Maximum Yield CAN Nov/Dec 2012 by Maximum Yield

CANADA November-December 2012

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Organic Hydroponics

The Debate Continues...

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New Gear From the Grow World

Achieving the Perfect Harvest:

Consider the Climate Factor

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DIY Alert:

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LONG BEACH

CALIFORNIA

NOVEMBER 3-4, 2012

2012

CONTENTS November/December 2012

FEATURES 6 5

52 44 In Control

Choose Growing Media by Guy Sela

32 Master Media by Shane Hutto

38 Ventilation Systems for Greenhouses and Indoor Gardens

by Eric Hopper

26 DEPARTMENTS 6

From the Editor

You Tell Us

MaximumYield.com

Talking Shop

48 Perfecting the System

Letters to the Editor

Max Mart

Simon Says

Distributors

52 Mixing Your Grow Mediums

MAX Facts

Do You Know?

Product Spotlight

Coming up next issue

by Stephen Keen

by Lee McCall

by Chad Garbet

54 Ocean of Air by Grubbycup

56 Photosynthesis, Maximized. by Dr. Lynette Morgan

62 Small Space Oasis by Kristen McKenzie

26 How to Successfully

Maximum Yield Canada | November/December 2012

FROM THE EDITOR | Jessica Raymond Fall is here and many of you are ready to bring your crops inside if you haven’t done so already. This issue focuses on mediums and ventilation, two important components of a successful grow that often get overlooked. The industry experts who contributed articles this month share some great insight on these topics to help you grow bigger and better. On the topic of mediums, Guy Sela details the physical properties growers need to be concerned with when choosing between the options available and Shane Hutto helps you navigate the oftentimes confusing world of soil and soilless mediums. Are your plants too hot or too cold? Are they getting enough CO2 or are they getting too much? Air in a growroom or greenhouse can be hot, stale and suffocating thanks to grow lights and other heat-emitting equipment. Your plants simply want to be comfortable, which is why Eric Hopper’s article helps you Jessica Raymond, editor ensure your greenhouse or indoor garden is properly ventilated and Grubbycup instructs on how to deliver editor@maximumyield.com a life-sustaining breeze to your indoor crops. In addition to media maintenance and ventilation advice, this issue delves into some of the other top-of-mind growroom issues like maximizing photosynthesis, controlling climate and gardening for apartment dwellers. There is a lot here for you, so enjoy this issue and be sure to drop us a line with your success stories or queries. We are here to help!

VOLUME 15 – NUMBER 5 November/December 2012 Maximum Yield is published monthly by Maximum Yield Publications Inc. 2339A Delinea Place, Nanaimo, BC V9T 5L9 Phone: 250.729.2677; Fax 250.729.2687 No part of this magazine may be reproduced without permission from the publisher. If undeliverable please return to the address above. The views expressed by columnists are a personal opinion and do not necessarily reflect those of Maximum Yield or the editor.

Publication Agreement Number 40739092 Printed In Canada PRESIDENT/PUBLISHER - Jim Jesson GENERAL MANAGER - Don Moores BUSINESS MANAGER - Linda Jesson editorial editor@maximumyield.com Editor-in-chief Jessica Raymond Assistant Editor Jessica Skelton ADVERTISING SALES Ilona Hawser - ilona@maximumyield.com Ashley Heppell - ashley@maximumyield.com Emily Rodgers - emily@maximumyield.com Kelsey Hepples - kelsey@maximumyield.com DESIGN & PRODUCTION ads@maximumyield.com Art Director Alice Joe Graphic Designers Liz Johnston Jennifer Everts Dionne Hurd ACCOUNTING Tracy Greeno - accounting@maximumyield.com Tara Campbell - tara@maximumyield.com

CANADIAN DISTRIBUTION Brite-Lite Group • Biofloral • Eddis Wholesale • Greenstar Plant Products Inc. • MegaWatt • Quality Wholesale USA DISTRIBUTION Aurora Innovations • BWGS • General Hydroponics Humbolt Wholesale • Hydrofarm • Hydro International National Garden Wholesale/Sunlight Supply • Nickel City Wholesale Garden Supply • R&M Supply • Tradewinds UK DISTRIBUTION Direct Garden Supplies • Growth Technology • Future Harvest Development Europe • Hydrogarden Nutriculture UK • Dutch Pro • Maxigrow AUSTRALIAN DISTRIBUTION Dome Garden Supply • House N Garden • Futchatec • Growth Technology • Hydraspher

Share this issue and your love of growing with others! Direct your friends to maximumyield.com for their free digital subscription.

Maximum Yield Canada | November/December 2012

contributors Dr. Lynette Morgan holds a B. Hort.

Eric Hopper has over 10 years of

Kristen McKenzie spent the last

Lee McCall is an alumnus of Johnson

Grubbycup has been an avid

indoor gardener for over 20 years. His articles were first published in the United Kingdom, and since then his gardening advice has been published in French, Spanish, Italian, Polish, Czechoslovakian and German. He is also considered one of the world’s leading authorities on crochet hydroponics.

Chad Garbet considers plants the

& Wales University. His extensive culinary background helped him gain experience in and knowledge of fine dining and food production, which developed into a career in the hydroponics and year-round gardening industry. Lee and his business partner use their Denver-based businesses to educate the public on sustainable gardening and high-quality produce.

Shane Hutto is a technical advisor

Guy Sela is an agronomist and a

Stephen Keen has been an indoor

experience in the hydroponic industry as both a retail store manager and owner. He continuously seeks new methods and products that could help maximize garden performance. Eric resides in Michigan where he and his family strive for a self-sufficient and sustainable lifestyle.

Tech. degree and a PhD in hydroponic greenhouse production from Massey University, New Zealand. Lynette is a partner with SUNTEC International Hydroponic Consultants and has authored five hydroponic technical books. Visit suntec.co.nz for more information.

chemical engineer for his innovative software company, Smart Fertilizer (smart-fertilizer.com), which provides fertilizer management solutions. Applying his background in water treatment, he has lead a variety of projects on reverse osmosis, water disinfection and water purification, and providing high-quality water for irrigation.

at Grodan Inc. He earned a bachelor’s degree in horticulture at Oklahoma State University and received a research assistantship for his master’s degree. During his graduate studies he researched production and extraction of surface waxes on horticultural commodities. His passion for growing is complimented by his experience in many types of controlled environment operations and design.

10 years living in Vancouver, BC. Previously the communications specialist for Tourism Richmond, she also wrote for a variety of British Columbia publications including Vancouver View, VanCityBuzz.com and 24 hours Vancouver. You can follow her expat adventures on Twitter @MissAboutTown most fascinating things on our planet. Trying to get information about growing plants out to the general public is his goal. He works at Word of Mouth Hydroponics Inc. in Nanaimo, British Columbia where he passes his growing knowledge to customers. Chad wants to see jungles inside our major cities and on every corner on every street.

gardening hobbyist for nearly 10 years. His personal successes with his garden led him to want to bring new ideas, mainly water-cooling, to the mainstream, which led to the founding of Hydro Innovations.

COMING UP ON THE WEB Final Stop of the 2012 “Grow Like a Pro” Tour Combines Indoor Gardening and Hydrolife Expo This world-class event will be a combination Indoor Gardening and Hydrolife expo featuring leading O experts from the hydro, A PR! E snow, surf, skate and K LI TOUR bike industries. Held at the beautiful Long Beach Convention Center for the third year running, this expo provides the ideal location with the perfect mix of culture and climate. Visit indoorgardeningexpo.com for complete event details.

Free Digital Subscription to Maximum Yield Canada Now you can receive Maximum Yield Canada free to your inbox every month. Subscribe to the digital edition of Maximum Yield by simply filling out the form at maximumyield.com/digital-subscription

W GRO

We’re happy to announce we have special group flight rates with WestJet to our trade shows. Visit us online at indoorgardeningexpo.com to receive the promo code.

Got Questions? Get Answers. Maximum Yield’s resident experts are available and ready to answer your modern gardening questions. Email editor@maximumyield.com or fill out the “Ask the Experts” question form on maximumyield.com

Maximum Yield Canada | November/December 2012

Connect with US maximumyield.com facebook.com/MaximumYield indoorgardeningexpo.com twitter.com/max_yield

Maximum Yield Canada | November/December 2012

LETTERS TO THE EDITOR Commenting on Compost

First of all, I’d like to start by saying I love the magazine. The Greenhouse and Water issue (Maximum Yield Canada, July/August 2012) had a lot of pertinent subjects. I especially enjoyed the article on biodynamic compost. I think it would be great if you could fill people in a little more in a future issue on how to make their own; especially because here in eastern Canada, I’ve never seen it sold. Can you [also] publish an article on essential microbes? [It’s] a subject I’ve just heard of from a knowledgeable person working at one of the indoor gardening stores in your directory. When I asked for Alaskan humus, wanting compost that was supercharged with microbes and many beneficial strains of fungus like mycorrhizae, he told me to look into essential microbes, populations of microorganisms and beneficial bacteria you can harvest, colonize and breed yourself. Thanks for increasing awareness in diverse issues pertaining to this beautiful art and science of growing plants in progressive ways. Sincerely, Oskar Newsman, aka G.I. Grow Stay tuned for upcoming issues of Maximum Yield, which will highlight many of your requests, and hopefully, answer these questions and more.

via Facebook

Great Minds in Agreement “As humans, we tend to consider ourselves the most central entity in the universe. It’s called anthropocentrism and it is rampant in modern society. We think we have the world under our thumbs, and we have screwed it up in the process. Take artificial fertilizers, nuclear bombs, water fluoridation, table salt, clear-cutting virgin forests for paper, pharmaceuticals and processed foods. On every level, we have removed the magic and replaced it with materialism.” Evan Folds Evan, I couldn’t agree with you more. It’s like your right inside my head. I totally support this type of analytical and responsible thinking toward our modern world. I think a good way to start fixing our mistakes is by first acknowledging them as a community, then making baby steps to change our views and actions toward sustainability, healthy living and the value of life on earth and its delicate biological systems. Matt Stergiou

We’ve Got You Covered

Great magazine this month. I hate to judge a book by its cover, but I knew from the cover I would enjoy it; and sure enough, I am. Keep up the good work helping people get their maximum yield. Davy Stanford

Nuts About Nutes

Loving the new issue this month! The focus on the nutrients was especially awesome. North Country Hydroponics

From Stressed Out to Easy Street

Falling for You

Is there any way to get a subscription of Maximum Yield (MY) in the mail? I fell for MY and I always get excited for the next issue. I know there is the digital copy and it’s good for going green, and I know I can view the magazine on my smartphone, but it’s just not the same. I like having the actual magazine ... that I can carry with me everywhere. I love the magazine and articles. [As a new cultivator], I have learned much from the MY mag. Thank you for your time and producing such a great magazine for free! Phillip Good Of course! A subscription form is available for download from maximumyield.com/subscriptions 10

Maximum Yield Canada | November/December 2012

Because of your magazine, I was able to pinpoint the problem of my garden. It was in bad shape for a couple weeks. Turns out heat stress caused by 37°C weather and no airflow, plus a small case of chlorosis, is bad combo. I’m a first-time gardener; after about three years, [I became] seriously fed up with in-ground garden maintenance, weeding and such. It was too big of an area to maintain by myself, so I started a grow box. It’s much easier, I must say, as far as maintenance goes. I just want to say thank you for the education and I hope to [attend] your next garden trade show in Long Beach, CA. Juan Martinez

We want to hear from you! Maximum Yield Publications Inc. Snail-mail: 2339 Delinea Place, Nanaimo, BC V9T 5L9 Email: editor@maximumyield.com Twitter: twitter.com/max_yield Facebook: facebook.com/MaximumYield

Maximum Yield Canada | November/December 2012

simon says

Hey, I was wondering if organics, such as guanos, can be used for hydroponics, and is guano enough for a full schedule for the veg and bloom stages?

The awkward partnership of organics and hydroponics intersects once again! There is a lot of debate about using organics in hydroponics. While it is feasible in theory, it is very difficult to make it function in the real world. In the successes I have seen myself, they are generally based on compost-amended soilless mixes; if they are water systems, the crops are low-nutrient-requiring plants, such as lettuce and some herbs. Most of the problems associated with organics and hydroponics are related to the level of soluble nutrients. Nitrogen and calcium availability would be two of the biggest problems. Organic products, unless digested through enzymatic action, fermentation or chemical extraction are generally only partially soluble, if at all. Powdered guanos would be mostly insoluble, although they could be suspended in solution if agitated. However, just because something is suspended doesn’t mean that plants will be able to access it. In most cases, the best way to digest organic material is through microbial action. In hydroponics systems, there would be very low levels of microbial action and it’s unlikely that you could get enough activity to break down the guanos into usable forms. There are a range of guanos available in the market. Most are from bats and birds, and they all have various nutritional ranges due to the variety of food sources consumed by the animals. Guanos can be a great way to get a high-power organic option into your garden and, nutritionally, you are right that guanos could be a very strong nutrient foundation. Outdoors, in true soils, where guanos can break down over a season in the presence of vast amounts and diversity of microbes, it’s possible they could provide a stand-alone nutrient for your garden. Indoors, guanos will require a bit more preparation in order to give the results you want. If you are keen to use guanos, the best idea would be to choose a soilless mix with a high level of biological activity. Add as many microbes as possible with inputs 12

Maximum Yield Canada | November/December 2012

like worm castings, weekly doses of an aerated compost tea and microbial stimulants like kelp and humic acid. Mix the guanos into your potting mix prior to planting and let the microbes feed themselves and, in turn, your medium and plants. The organic material would break down over a few months and provide a natural slow-release nutrient supply for your plants. To fill the gaps and ensure the best crop possible, I would consider having a fermented liquid organic ready, just in case the release curve doesn’t keep up with your plants. Keep thinking organically and, as always, I recommend experimenting; every situation is different and you won’t know unless you try. MY

Do you have a question for one of our resident experts? Send it to editor@maximumyield.com or fill out the form on maximumyield.com and your answer might be printed in an upcoming issue.

MAX FACTS

hydroponic news, tips and trivia

Goats used to eliminate weeds in B.C. pilot project Instead of using herbicides, park officials in Kamloops, British Columbia are turning to goats to help get a handle on invasive species, such as knotweed, that can quickly take over the natural landscape. Armed with their appetites and a digestive system that will kill any seeds that are excreted, the herd from northern Alberta could solve, or at least slow down, the region’s weed problems. At the moment, the goats—which are herded to make sure they eat only weeds—are tasked with feasting on toadflax. (Source: ctvnews.ca)

MAXFACTS

hydroponic news, tips and trivia

Quebec’s Jardin de la Connaissance Sprout Mushrooms and Moss Two years after Quebec’s Jardin de la Connaissance was created using old books, giant mushrooms are starting to sprout. While some fungi have appeared naturally, the gardens’ creators are also cultivating large mushrooms between the pages and have recently begun to introduce moss graffiti to the garden. (Source: inhabitat.com)

B.C. and Ontario Score highest in environmental progress British Columbia and Ontario score highest in environmental stewardship, according to Corporate Knights, a Toronto-based quarterly focused on “clean capitalism.” The aim of the report was to assess the environmental progress of Canada’s 13 provinces and territories by looking at key indicators in seven categories: air and climate, water, nature, transportation, waste, energy and innovation. Corporate Knights based its findings on the most recent available data from Statistics Canada and Environment Canada, as well as a handful of reports from the provinces and industry associations. British Columbia and Ontario both score an A- in the survey, with Prince Edward Island finishing close behind with a B+. Alberta and Saskatchewan sit at the bottom, each with a rating of C. (Source: cbc.ca)

Maximum Yield Canada | November/December 2012

MAX FACTS

hydroponic news, tips and trivia

Vermicompost Beneficial for Organically Grown Tomatoes Marketable yields of organic horticultural crops frequently fall below those of conventional crops. However, researchers recently concluded that the addition of vericompost to organic substrate was beneficial for tomato growth. In addition to the benefit of higher yields, the substrates containing vermicompost also produced a significantly lower incidence of defective fruit. (Source: sciencedaily.com)

New Integrated Building Model Might Improve Fish Farming Operations Aquaculture researcher Andy Danylchuk and his colleagues at the University of Massachusetts Amherst are offering an affordable, more holistic and sustainable approach to indoor fish production. By melding building design, fish ecology and aquaculture engineering techniques, they created the first-of-its-kind “building-integrated aquaculture” (BIAq) model, which will allow fish farming operations to be located close to markets and to succeed even in cold climates. (Source: sciencedaily.com)

Underwater Carbon Storage Seagrasses are recognized for their many ecosystem benefits, such as filtering sediment, serving as habitats for marine life and protecting coastlines against floods and storms. Now researchers have found that seagrass meadows might also reduce greenhouse gas emissions and increase carbon stores. Studies show that coastal seagrass beds can store up to 83,000 metric tons of carbon per 3.99 sq km (mostly in the soils beneath them) and that the global carbon pool in seagrass beds is as much as 19.9 billion metric tons. Seagrass meadows can store up to twice as much carbon as the world’s temperate and tropical forests. (Source: nsf.gov) 16 16

Maximum Yield Yield Canada | November/December Canada | November/December 2012 2012 Maximum

Maximum Yield Canada | November/December 2012

MAX FACTS

hydroponic news, tips and trivia

How Plants Chill Plants elongate their stems when grown at high-temperature to facilitate the cooling of their leaves, according to new research from the University of Bristol. When grown at higher temperatures, plants have an elongated, spindly architecture and develop fewer leaf pores, known as stomata. The researchers suggest that the increased spacing of leaves observed in high-temperature-grown plants might promote the diffusion of water vapour from stomata, thereby enhancing the cooling process. Understanding why plants alter their architecture in response to heat is important as increasing global temperatures pose a threat to future food production. (Source: sciencedaily.com)

Fixing Flavourless Tomatoes Scientists now know flavour intensity in tomatoes traces to 12 different compounds and sweetness to another 12, including eight that were also important for overall flavour. “This is the first step to restoring good flavour in commercial tomatoes,” stated one of the researchers. “One could do worse than to be known as the person who helped fix flavour.” (Source: treehugger.com)

War on Food Gardens When Josée Landry and Michel Beauchamp of Drummondville, Quebec turned their front lawn into a vegetable garden this spring, city officials told them they would have to remove the garden or else face a daily fine of up to $300. The town code stated that a vegetable garden couldn’t occupy more than 30% of the area of a front yard. However, after receiving a petition with 30,000 signatures, the city announced in August that front yard kitchen gardens would be allowed. The couple was also invited to help shape new guidelines for urban food gardens. (Source: warmearth.com.au)

Maximum Yield Canada | November/December 2012

Maximum Yield Canada | September/October 2012

PRODUCT SPOTLIGHT YOUR GUIDE TO THIS ISSUE’S

HOTTEST ITEMS Ask for them at your local indoor gardening store

Introducing F5 Fans From DL Wholesale The ultra-powerful F5 Fans use advanced mix-flow technology and have a specially engineered aerodynamic design that allows them to achieve an unheard of level of performance and efficiency. These fans, available in 20.32, 25.40 and 30.48 cm, maintain high CFM ratings, have powerful internal drive motors, are aerodynamically designed, feature UL-recognized components and have an attached 20.32-cm power cord and mounting brackets. Visit your favourite hydroponics shop to learn more.

Sun System T5 HO Croplight 44 and 48 Sunlight Supply®, Inc. is excited to announce the arrival of the Sun System® T5 HO CroplightTM 44 and 48 Fluorescent Fixtures. The Sun System® CroplightsTM are affordable, energy-efficient T5 high-output horticultural light fixtures. With a low profile and lightweight commercial design, the T5 HO Croplights can be easily handled. This flexible fluorescent fixture can be operated vertically or horizontally to fit all of your gardening needs. Not only is the Sun System T5 Croplight reliable, but it includes durable Stucchi sockets for a long life. Visit your nearest indoor gardening shop to learn more.

Root Pouch Introduces Boxer Brown, the Most Durable Pot Available Root Pouch’s most rugged line is designed to be used season after season. Our Boxer Brown pot is perfect for the great outdoors and hydroponic growing systems, and is available with and without handles. The brown fabric is made of recycled water bottles. All seams and stitching are reinforced and done with an industrial-strength stitch to deliver a stronger, sturdier bag. In tests, the bag has been reused and washed 20 times. When a kangaroo fights with another kangaroo, it is often considered boxing, which is where the name Boxer Brown originated. For more information, visit your favourite indoor gardening shop.

Ideal Air 30-pint Dehumidifier If too much moisture in your grow area is an issue, Ideal-Air has you covered. The 30-pint Dehumidifer from Ideal-AirTM offers an easy-to-use digital display panel with humidity readings, 4.92-L reservoir and a removable, washable filter. The built-in defrost system is designed for operation down to 7°C. A versatile machine, this dehumidifier has an automatic shut-off when the reservoir tank is full or it can be plumbed for permanent drainage. It also offers automatic restart in the event of a power failure. Designed with a heavy-duty compressor and two-speed fan motor, the Ideal-Air 30-pint Dehumidifier offers flexibility in user applications. Perfect for Sun Hut® and Grow Lab® grow tents. Visit your favourite indoor gardening shop to learn more.

Maximum Yield Canada | November/December 2012

PRODUCT SPOTLIGHT

Inda-Gro’s Induction Grow Lights Inda-Gro Induction Lighting Systems only manufactures induction grow lights. First discovered in 1891 by Nikola Tesla, induction lamps have always been known for their energy efficiency (they consume up to 70% less power than HID lamps), long life and low operating temperatures. IndaGro Induction Grow Lights combines these proven efficiencies with broad-spectrum PAR-weighted phosphors for explosive growth and high yields all from a single lamp source. Our grow lamps also use an electrodeless fluorescent discharge lamp (EFDL) technology. With no internal electrodes, these lamps offer low lumen depreciation and a rated life of 100,000 hours. Visit an indoor gardening shop near you to learn more.

Grozone’s Ultra-simple CO2 Controller now Available

Forever Flowering Introduces the Breathable Wall Greenhouse and indoor growers now have the ability to move high volumes of air without transferring light. The Breathable Wall has only a 5% air restriction on any size fan. It comes in a variety of sizes and can be adjoined to create passive walls in greenhouses or single units for exhaust fans and intakes. Indoor growers can install the Breathable Wall at any intake or exhaust point. Plus, it can be used to create separate light zones without adding more cooling systems. Adapter plates for ducting are also now available. For more information, visit your favourite indoor gardening or specialty greenhouse retail shop.

Are you satisfied with the value line of CO2 ppm controllers? Do you want something better? If so, the new Grozone Ultra-simple CO2 (US CO2) Controller is your answer. It’s the ultimate in affordable and easy-to-use CO2 controllers. The US CO2 features one-button calibration, five pre-set CO2 control values (1,000; 1,125; 1,250; 1,375 and 1,500 ppm), five pre-set elevation values for improved CO2 control in higher altitudes (sea level, 304.80, 914.40, 1,609.34 and 2,133.60 m) and a three-LED display that shows ambient CO2 values. The controller also has a 5–A output and includes a photocell, so no timers are needed. For more information, visit your local indoor gardening shop.

LVC1 Grozone Low-voltage Relay A/C Controller Stop using high-amperage switchers to control your air conditioning (A/C); use the lowcost, easy-to-use LVC1 instead! The Grozone ETL-listed LVC1 is the module you need to convert any of your 120-V output into a low-voltage control relay—also called dry contact. Simply hook up the LVC1 screw terminals to the A/C low-voltage (24 V) control terminals—where the remote thermostat is normally connected—and you’re set. Only small gauge wires are necessary, since the 120- or 240-V power lines will be connected directly to the electrical box. Visit your local hydroponics shop to learn more.

Maximum Yield Canada | November/December 2012

PRODUCT SPOTLIGHT

Hydro-Logic’s SuperLogic Revolutionizing commercial water systems, the SuperLogic is smart and stylish. This fantastic system can handle up to 5,000 ppm, is available with a 2,500-gpd flow rate and even reverses the waste-toproduct ratio (one part waste to four parts product water, if purchased with a softener). Built to run all day, every day, the SuperLogic features built-in state-of-the-art diagnostic tools and even lets you control the total amount of TDS in your water. Want 37 ppm? No problem. Want zero? Done. For those who need the best in water filtration, Hydro-Logic’s SuperLogic fits the bill. Visit your favourite hydroponics shop to learn more.

Forever Flowering Introduces Their New Shade Cloth Forever Flowering has introduced the latest in shade screens. Traditional shade cloths are black or dark green. However, studies have proven that dark colors, like black and green, generate more heat. Our shades have been specifically designed with white reflective material to create the optimal shade of your choice. During the day, the screen’s open structure provides solar reflection and cooling, reducing greenhouse and plant temperature. At night, it helps reduce radiated heat loss from the plants. We have seen up to 30% more growth under these shades over the traditional style. They come in 30%, 40%, 50% and 60% transparency. For more information, visit your favourite indoor gardening or specialty greenhouse retail shop.

HT2 Digital Humidity and Temperature Controller With Photocell and Display This new Grozone product will evolve with your plants’ needs. The ETL-listed HT2 is a low-cost plug-in humidity/temperature controller with detachable digital sensor that can be positioned up to 7.62 m from the controller for precise temperature and humidity sensing in your garden. Whether you want to cool, heat, humidify or dehumidify your growroom, this specialty controller offers five operating modes to control different types of equipment according to plants’ growing stages or to the season of the year. The bar graph display shows accurate temperature and humidity readings at the sensor remote location. Different day and night set points are available to optimize your crop yield and plant quality. Visit your local hydroponics shop to learn more.

Measure Me Plastic Measuring Cups From DL Wholesale DL Wholesale now offers six sizes of super accurate Measure Me Plastic Measuring Cups. We offer sizes to fit all your growing needs including 250 ml; 500 ml; 1,000 ml; 2,000 ml; 3,000 ml and 5,000 ml. Each cup also has a detailed conversion chart conveniently printed on it to help you make sure all your measurements are accurate and on-point. All cups feature a sturdy handle and mess-free pouring spout. For more information, visit your local indoor gardening retailer.

Maximum Yield Canada | November/December 2012

by Guy Sela

Choosing the right growing medium for your crop is crucial to a great yield. Here, Guy Sela runs through all your choices of media according to their physical properties… 26

Maximum Yield Canada | November/December 2012

Container production has been expanding in recent years. Choosing the optimal medium requires special consideration because it is much more than just an anchor for the plant—it can be crucial to a successful crop. Physical and chemical properties of growing media differ from those of soil, and container production requires more attentive management.

Maximum Yield Canada | September/October 2012

how to successfully choose growing media

There are many advantages to using growing media: • High yields can be achieved in a limited area • Better control over irrigation and fertilization • Easier disinfection • Recycling of drainage water is possible • Growing media can be used as an alternative to an inadequate soil However, there are also some disadvantages: • Nutrient-holding capacity is low • Buffer capacity is low and, therefore, changes are rapid

water. Another important property is the medium’s weight. It should be light enough for easy and less expensive transport and handling, but it should also be heavy enough to provide physical support to the plant.

Growing medium and production system compatibility It might be surprising, but in order to choose the best medium, the first thing you should do is consider the production system’s specifications. These factors include

In this report, we focus only on the physical properties. The chemical properties will be discussed at a later date.

“Physical and chemical properties of growing media differ from those of soil, and container production requires more attentive management.” Figure 1

Physical properties of the growing media A balance between air content and available water is one of the most important requirements of good media. Ideal growing media provide plants with adequate water supply and, at the same time, contain enough air to allow gas exchange and supply oxygen to the root system. Aeration is critical for optimum plant development, as a lack of adequate aeration results in poor plant growth, susceptibility to diseases and nutrient deficiencies. Good growing media are also characterized by high hydraulic conductivity—that is, the ability to transmit

Figure 2

the type of irrigation technique (dripper’s density and discharge), container size and container shape. These specifications and the growing medium must be compatible in order to obtain effective and uniform distribution of the irrigation water.

Porosity and water-holding capacity Each growing medium has a characteristic particle-size distribution. The spaces (pores) between the solid particles can be filled with either air or water, and are referred to as “total porosity.”

Maximum Yield Canada | November/December 2012

how to successfully choose growing media

Each medium contains pores of various sizes. Smaller pores can retain water with more force than larger ones and a large pore cannot hold water against gravity. As such, the higher the pore is positioned in the container, the smaller it has to be in order to retain water against gravity. So, pores at the top of the container that are too large to hold water against gravity are empty; therefore, the top of the container will always be dryer than the bottom. At the bottom of the container, all pores— including the largest—are filled with water, making the bottom layer saturated. Let’s visualize... Pores in a growing medium can be viewed as a series of capillaries. In our model (see Figure 1), the width of the

“A balance between air content and available water is one of the most important requirements of good media.”

column represents pore size and the capillaries have been “ironed out” so they are straight and can be easily compared to each other. It is easy to understand why the bottom of the medium is always saturated, while the top of the medium contains less water and more air. There are forces that make the water climb in the capillaries against gravity—however, these will not be discussed here. We will only mention that they are called cohesion (which is the affinity between water and particles surface) and adhesion (which is the affinity between water and itself).

in centimetres and the data can be graphically presented as a water retention curve. Some labs refer to the height as “tension in centimetres.” Let’s take a look at an example of water retention curves for two different growing media (see Figure 2). The two media have completely different behaviours. Medium B drains more easily and holds less water than medium A at any given height (tension). For example, at 20.32 cm, medium A holds 60% water, while medium B holds only 23%. This is because medium A contains a higher percentage of smaller pores. Therefore, a grower who decides to grow in medium B under the same conditions (irrigation technique, container size and shape, and cultivar) has to give more frequent irrigations. On the other hand, if the grower decides to grow in medium A, his main concern would probably be lack of aeration. Figure 3

Water retention curves Labs can accurately measure the water percentage by volume (v/v in %) at given heights of the medium, after saturation and drainage. The height is measured

Other information that we can obtain from water retention curves is the amount of water available to the plant roots. We know that tiny pores can retain water extremely well; however, they might also hold water so forcefully that the plant cannot absorb it. In growing media, water at tensions of 50.80 cm to 1.02 m is generally considered unavailable to the plant because it is retained in very small pores. In addition, a high content of unavailable water can set the stage for fungal problems and other diseases present in high humidity conditions.

Container size and shape It was mentioned above that the size and shape of the containers in which the medium is placed determine the amount of water that it holds. Take a look at the containers in Figure 3: All containers are of the same

Maximum Yield Canada | November/December 2012

volume and are filled with the same medium. The blue area represents water. Since it is the same medium, the water reaches the same height in each of the containers. Moreover, according to the water retention curve of this medium, the same water content in percent is measured at this height. However, due to the different shapes, the actual amount of water is different in each container. This results in a different water/air ratio in each container and in different irrigation management needed. Irrigation frequency and amount of water applied with each watering are determined by the available water content of the medium and by the container shape and size. For example, one irrigation cycle a day is not enough if the daily water consumption of the plant is higher than the amount of available water in the medium.

“Smaller pores can retain water with more force than larger ones and a large pore cannot hold water against gravity.” Hydraulic conductivity As the name suggests, hydraulic conductivity is the rate at which a medium transmits water. Hydraulic conductivity of media is not routinely measured in lab tests. Nevertheless, it is extremely important to understand its significance. Hydraulic conductivity is, in fact, the limiting factor of water uptake by plants in container media (rather than the water quantity in the medium). When transpiration rate exceeds the hydraulic conductivity of the medium, the plant cannot efficiently use the water contained in the medium and could wilt. In materials used for container media, the hydraulic conductivity decreases exponentially as the medium dries. This is because continuity of water is disrupted after the larger pores empty. MY

Maximum Yield Canada | November/December 2012

Master Media by Shane Hutto

Mr. Hutto takes us on a tour of all the different mediums you can use to grow healthy, happy plants. 32

Maximum Yield Canadaâ&#x20AC;&#x201A;|â&#x20AC;&#x201A;November/December 2012

Master Media For most of us, the beginning was all about what to grow—and we thought about that long and hard—but what we’d grow that stuff in was an afterthought. Once you have your light source and your space set up, though, you’ll finally start thinking about what medium to use. Most of the time, you start with what your mentor uses: whether it’s your buddy, your local retailer or an author who’s work you’ve read on the Internet. Typically the first person who tells you what they use and sounds like they know what they are talking about is who you end up following. This usually gets you at least something in the way of yield if you’re lucky, but we all want to get the most out of our garden. Today’s consumer is bombarded with choices. Rockwool, expanded clay, coco coir and peat mixes (what most call soil or soilless mixes) all have their pros and cons, and each of these choices is available in its own particular varieties and brands; so, obviously, a beginner can be overwhelmed quickly. The fundamental questions to ask yourself before making this decision are: how well do you read instructions and how often do you plan to check on your plants? As a beginner, you will have to learn when and how much to water and feed your plants, regardless of the type of medium you are using. Getting the most out of your garden is about finding a balance between how much effort you need to put in and how much time you have to devote to your hobby.

Follow the instructions When preparing your medium, the most important advice I can give you is to follow the instructions; they are on the bag for a reason! Most peat mixes are ready to go and require very little preparation other than filling up your plastic pots. Rockwool is rather easy to prepare as well— the whole 24-hour soak requirement is simply a myth; you just have to rinse the rockwool in ph-5.5adjusted water for , a few minutes. After the presoak, it’s ready to use. Expanded clay is similar in preparation to rockwool in that it must be rinsed—with plain water—but it must then also be agitated to remove the excess sediment. Then you just need to fill your system and you’re good to go. Coco coir is a preparationintensive medium. It does come in bags, but it still usually needs the salts rinsed out. Mostly, though, it comes in bricks, which are convenient to carry, but expand significantly once water is added. The bricks must be soaked and broken up—I like to use a garden spade and break them up while they are soaking. Coco coir must also be rinsed after it is broken up to ensure the high salt content is flushed away.

eXPANDED Clay has a very good structure and will allow plant roots to penetrate outside the clay forming massive roots.

Maximum Yield Canada | November/December 2012

Regular sanitation Another task that is a big consumer of time is regular sanitation. In any controlled growing environment, whether it’s indoors or in a greenhouse, regular cleaning is a must. Whether it involves picking up dead leaves and bugs or just general floor cleaning, there’s always something to do. Which medium you use will make a difference in how long your cleaning chores will take. Coco behaves a lot like peat in this category; when dry, it flies all over the place and seems dusty. Expanded clay is good in that it doesn’t fly around, but drop part of a bag or a net pot full of those round clay balls, and they roll everywhere. Rockwool tends to be dust-free after the initial wetting and once it’s in place, it pretty much doesn’t move unless you move it!

Watering and feeding The next major task that needs to be figured out is to determine how often you need to water or feed your plants. This is also the job that is the easiest to mess up, no matter which medium you’ve chosen to use. The answer a horticulturalist will tell you is “when the plant needs it.” You can certainly overwater plants in an indoor garden—if you watered peat two times a day in an indoor environment, the plants would be dead in a couple of weeks! Soilless mixes should be checked for moisture by feeling the weight of the pot or by sticking your finger a few centimetres below the surface to feel the moisture yourself. Another characteristic of the soilless mixes is they change to a lighter colour as they dry and if you practice, this can be a good indicator of when to water. Expanded clay feeding is almost the opposite; it can pretty much be watered throughout the daily light cycle and remain viable because it retains virtually no moisture. Coco retains nutrients well, but it also drains well. Rockwool also falls in the middle: it’s designed to hold air and water evenly so it can be watered frequently, but it still holds enough air for the roots to breathe. The amount of water your plants need will fluctuate the most in rockwool. On the hottest days (or under strong light) they should be watered often with short-duration soakings, but for cool, windless days, they might be watered only once. Factor in all these considerations when deciding whether a medium is going to be easy for you to work with. The truth is that they

When preparing your medium, the most important advice I can give you is to follow the instructions; they are on the bag for a reason!

Maximum Yield Canada | November/December 2012

Master Media

are all user-friendly to a degree and you must decide which is best for your needs. The peat mixes are user-friendly in that you do not have to monitor the pH too much and you’ll still get a nice plant. Expanded clay is great because it’s really hard to overwater. Rockwool and coco both have their ups and downs for new growers. Rockwool is an easy medium to use because what’s in it is what you feed it; there are no hidden nutrients or other factors to consider in the root zone and it allows you to know exactly what you’re doing—whether you’re doing it right or wrong. I do tend to advise most new growers of the somewhat temperamental nature of coco as a growing medium.

Which medium you use will make a difference in how long your cleaning chores will take.

Cost comparisons Once you have chosen your preferred medium, you’re off to the store to compare prices. Many of us start rethinking our options at this point! On first impression, the peat mixes seem like the clear winners for cost, but then you must consider the amount of peat it will require to handle the size of plants you plan to work with. Expanded clay has a very good structure and will allow plant roots to penetrate outside the clay, forming massive roots. Coco holds nutrients very well; it’s expensive, but can produce quality root masses. Rockwool actually has the best root mass-to-product volume in the hydro industry—it is manufactured so that a rock will expand to 50 times its size, with an equivalent amount of rock fibre. All that extra space is air space, into which roots can grow.

Media maintenance All growing media require regular maintenance, which means that at some point your crop’s life cycle will come to an end and the media will have to be replaced or reused. The one thing to keep in mind when reusing any medium is that plant diseases are almost always species-specific. Media like expanded clay are cost-effective because they can be reused several times, but must be thoroughly washed between crops. The other thing about expanded clay reuse is that after several 36

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uses the rocks begin to break down and fall apart; remember, we are dealing with water—the same destructive force that made the Grand Canyon! Rockwool can be reused, but it has to be reprocessed first, back at the factory. In Europe, a high percentage of commercial growers send back their used rockwool to be melted down and made into ‘new’ rockwool again. In North America, used rockwool from indoor growers is sometimes made into bricks for house building. Your used rockwool can be tilled into the garden for aeration, or it can also be reused for other species in potting containers. Coconut coir is not reused often, due to its propensity to hold high microbial counts. This happens because root zones establish beneficial fungi and bacteria that thrive as long as plants continue to grow, but once they are harvested the roots will begin to decay and diseases will be present in the medium. Peat mixes are very similar to coconut in this respect—it can be steam sterilized under high temperatures and pressure, but not everybody has the kind of expensive equipment this process requires. Once you’ve mastered growing in each of the media we’ve discussed, you’ll probably begin to think about plant quality. However, that’s material for another column. For now, you should realize that each medium offers its own set of challenges and benefits, but finding the one that’s right for you and your situation is key to success in your early gardening experience. Maximum Yield Canada | November/December 2012

Ventilation Systems

for Greenhouses Indoor Gardens by Eric Hopper

Ensuring your greenhouse or indoor garden is properly ventilated is every bit as important to the health of your plants as adequate water and proper nutrition. Here’s a quick guide to the basics…

Maximum Yield Canada | November/December 2012

Ventilation Systems for Greenhouses and Indoor Gardens

The ventilation system is the most important aspect of environmental control in any greenhouse or indoor garden. Plants can be given perfect lighting conditions and the most complete diet of nutrients, but without a properly functioning ventilation system, they will inevitably suffer and fall short of their potential. Ventilation systems for both greenhouses and indoor gardens serve the same four very important purposes: temperature control, humidity control, air circulation and—if it is not being supplemented—CO2 replenishment.

Temperature Probably the most obvious reason for ventilation systems is to control temperature. Ventilation systems are commonly used to remove excess heat—either created by trapped radiant energy from the sun or by high intensity discharge lighting—from the growing environment. An exhaust fan, like its name suggests, exhausts unwanted heat and stale air from the garden and is usually the first piece of equipment purchased for any ventilation system.

Humidity The humidity level within an enclosed garden is affected by multiple variables. Temperature differences between the inside and outside of an enclosure can cause condensation, which directly affects humidity levels. Plants naturally transpire water, which will also raise the humidity level within an enclosed space. Exhaust fans used to remove unwanted heat can also serve the secondary purpose of removing excess humidity, which would otherwise be trapped in the garden space.

Air circulation Air circulation refers to the air movement within the physical garden space. Greenhouses and indoor gardens alike can benefit greatly from oscillating fans, which create consistent air movement. Not only does consistent air movement result in uniformity of temperature and humidity within the growing environment, it also helps strengthen the structural integrity of your plants.

CO2 replenishment

Plants consume CO2 for photosynthesis and they expel oxygen. If the CO2 in an enclosed environment gets used up by the plants and is not replenished, the plants’ ability to photosynthesize will be compromised—ventilation systems replace stale, CO2-depleted air with fresh air containing new CO2 for plants to process.

Ventilation set-up for indoor gardens Heat naturally rises, so it is most efficient to have your exhaust fan positioned high in the growroom. The fresh air intake point should be placed low in the grow room, preferably on the opposite side of the room from the exhaust—this will ensure fresh air movement across

Maximum Yield Canada | November/December 2012

the garden. Air follows the path of least resistance, so it is important when setting up a ventilation system to determine where the air will flow. Imagine a string from the fresh air intake point to the point of exhaust—assuming there aren’t any large physical obstacles impeding airflow, this will be the ventilation path.

Fan sizing for indoor gardens Many factors will influence what size of fan you choose. Additional equipment like air conditioners, dehumidifiers and CO2 burners will all affect your choice of ventilation fans. For a starting point, let’s assume there will be no additional equipment and that the climate of your garden is about average. A good rule of thumb is to have 7.95 cubic metres per minute (m3/min) of air movement per 1,000-W light—for example, a room with 4,000-W should have an exhaust system a rating of 30.6 m3/ min or higher. For growers who decide to use a passive intake—with no fan—a slightly higher cubicmetre-per-minute rating for their exhaust might be necessary to create enough negative pressure to allow sufficient airflow. The opening for a passive air intake should be a minimum of twice the size of the exhaust. Gardeners who utilize an intake fan should choose one with a slightly lower rating than the exhaust fan, which will ensure a slight negative pressure in the growroom. An air conditioner can dramatically decrease the cubic metres per minute needed to exhaust heat and this should be taken into consideration when setting up any ventilation system. Generally speaking, every 10,000 BTUs of air conditioning will replace 7.95 m3/min of exhaust and should be able to efficiently cool a 1,000-W light. On the other hand, dehumidifiers and CO2 burners add heat to a growroom and might require you to install a larger exhaust fan.

Natural ventilation New cooling technologies and ventilation systems There have been many technological advances in indoor garden heat management in recent years, all of which can affect the sizing and set-up of ventilation systems. Air or water cooled reflectors will drastically reduce heat in the room, minimizing the required size of your exhaust fan. Some cutting-edge growers are now combining air- or watercooled reflectors, dehumidifiers and super-efficient mini-split ventless air conditioning units. Used in conjunction, these technologies reduce heat to a minimum and—as long as CO2 is being supplemented— make exhaust fans unnecessary.

Greenhouse ventilation Excess heat or stale air within a greenhouse will result in slow growth and poor overall crop performance. Ventilation systems can often prove the downfall of the novice greenhouse grower; many will never associate the mould, insects or diseases they have managed to acquire with having poor ventilation. There are two common ways to set up a ventilation system in a greenhouse: naturally or mechanically.

“ If possible, set up your fans to work in conjunction with the prevailing winds—this can help ventilation systems work up to 20% more efficiently.”

The keys to natural ventilation are wind and thermal buoyancy. Thermal buoyancy refers to the rising of warm air within the greenhouse, a process that actually contributes to efficient ventilation. A greenhouse utilizing natural ventilation will have either retractable or removable sides or roof panels, or a series of vents. Hoop houses with retractable sidewalls are great examples of using natural ventilation—when the sides are raised, the wind can flow through the greenhouse and replace warm, stale air with fresh air from outside. Greenhouses with a series of roof and sidewall vents remove heat via wind and natural thermal buoyancy. As wind passes over a roof vent it creates a vacuum within the greenhouse, which draws air through the sidewall vents and out the roof vents. Thermal buoyancy is most effective when there is a large temperature difference between the outside air and the air in the greenhouse. Cooler air enters the greenhouse through the sidewall vents and as the air heats up it rises and exits the greenhouse through the roof vents. On warm days—where the temperature difference is minimal— the buoyancy effect is not as powerful.

Maximum Yield Canada | November/December 2012

Ventilation Systems for Greenhouses and Indoor Gardens

Mechanical ventilation

Fan placement

Mechanical ventilation in greenhouses is very similar to that found in indoor gardens. Fan systems create air movement, which brings fresh air into the greenhouse and exhausts unwanted heat and humidity.

Exhaust fans should be positioned high on the wall opposite the intake vents so that air flows over the plant canopy on its way through the greenhouse. If possible, set up your fans to work in conjunction with the prevailing winds—this can help ventilation systems work up to 20% more efficiently. Passive intakes (with no fan) should be 1.5 times the size of the exhaust fan in order to ensure sufficient intake and to make sure exhaust fans aren’t overworked. If strong negative pressure is apparent—for example, if doors are hard to open because they are literally being sucked shut or the greenhouse plastic is being pulled tightly against the frame—the size of the passive intake opening needs to be increased. One highly efficient way of taking in and distributing fresh air in a greenhouse is by using a perforated polyethylene tube that inflates and extends among the plants. The intake fan fills the tube with fresh air and pushes it through the holes in the plastic, which allows fresh air to reach

Greenhouse fan sizing Fan systems operating during summer months should be sized to provide one volume of air exchange per minute, to a height of 3 m. We use 3 m as a constant when determining fan capacity for year-round greenhouses. The general rule of thumb for sizing fans is to multiply the greenhouse’s length in metres by its height in metres and then multiply by the constant—3 m. That number will give us the cubic metre per minute capacity needed to sufficiently cool the greenhouse—for example, calculating the fan capacity required for a 4.5 by 18 m greenhouse would look like this: 4.5 m x 18 m x 3 m = 243 m3/min capacity required for year-round cooling. Ventilation needs will vary with the seasons, and cooler months will require a less aggressive amount of air exchange. Most ventilation systems can be reduced to one third of full fan capacity in winter months, so it is advantageous for growers who plan on using their greenhouses year-round to invest in variable speed fans or fans that can be controlled by a dimmer or thermostat. Larger greenhouses might require multiple large fans for cooling during the summer months, but a reduced number of fans will be required during the winter.

“ The general rule of thumb for sizing fans is to multiply the greenhouse’s length in metres by its height in metres and then multiply by the constant—3 m.”

the plants in a direct and uniform manner. This technique is especially effective in larger greenhouses that would otherwise only have fresh air entering one end of the building. The use of perforated polyethylene tubes does require intake fans and—as with an indoor garden—these fans should have a slightly lower cubic-metre-perminute rating than the exhaust fans so they’ll produce a gentle negative pressure within the greenhouse. The ventilation systems we install in our greenhouses and indoor gardens are a vital component in our attempt to recreate nature indoors. Just as the wind strengthens, revitalizes and nourishes plant life outdoors, the ventilation systems in artificial environments directly influence plant health and production. Sufficient air movement—combined with proper fan sizing and placement—will reduce the potential for problems and can help create ideal conditions for efficient horticultural production.

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In Control: A Guide to Achieving the Perfect Indoor Climate

BY Stephen Keen

Does it seem like you’ll never achieve your ideal harvest? If you consider all the climatic factors, it might finally be within your reach.

Maximum Yield Canada | November/December 2012

As every gardener knows, hydroponics and indoor farming can present a number of challenges. Cycle after cycle, it seems there are always obstacles that have to be overcome. After each harvest, though, we challenge ourselves to do better next time—regardless of the hurdles, we keep at it and eventually we usually end up getting it right. One of the common early mistakes that gardeners make is failing to consider how absolutely vital climate is to the health and well-being of their plants. Temperature, humidity and CO2 levels in the garden have every bit as big an effect on the success of a plant as nutrients or lighting. And it’s not just the direct effect that climate variables have on your plants that must be considered, but also the indirect results—the more controlled the climate, the less inviting your garden will be to pests, pathogens, fungi and other harvest killers. Deciding exactly how to control the climate in your garden can be intimidating and we often underestimate our needs. The goal of this article is to help you consider all of the factors that will affect the climate in your own garden.

Heat Rarely is the novice gardener prepared for the sauna that their first garden can become! This is usually an early hurdle for the small gardener and an enormous consideration for commercial farmers. When you consider the size of your cooling system, remember that cooling anything is simply the removal of heat, which is measured in BTUs. You don’t add coolness to something—you take heat away from it. So, if you’re going to cool your garden, you have to consider how much heat is being produced in the garden and how many BTUs you will have to remove. Most cooling systems are measured in tons and one ton of heat is the equivalent of 12,000 BTUs. Lighting is the biggest contributor to your garden’s heat load. A standard 1,000 W HID bulb produces approximately 4,000 BTUs of heat (watt for watt, the heat production of an

"Rarely is the novice gardener prepared for the sauna that their first garden can become!"

Maximum Yield Canada | November/December 2012

In Control

"Gardeners in moderate or humid environments nearly always have to use a dehumidifier in the garden."

LED is similar to that of an HID lamp). Air cooling the reflector is commonly the first measure for removing this heat, but you aren’t really addressing the problem if the ambient temperature outside is hotter than you need your garden to be. Under most circumstances, air cooling can remove between 10 and 40% of the heat your lights produce. There are custom-fitted heat shields available through major reflector manufacturers that can be utilized to boost the efficiency of your air cooling—these reduce the amount of heat that can escape from the reflector, which increases the amount of heat being removed by your fans. There are some drawbacks to exhausting air outside of your garden as well—some of the circulated air will escape into the garden and it can carry pests and fungi with it. Also, if you’re using CO2, some of it will be drawn into your reflector airstream and out of the garden, increasing your need for CO2 production. If you’re using a CO2 burner, this actually adds to your heat load. Venting your room or exhausting air from the garden out and bringing fresh outside air in will present similar obstacles on a much larger scale. In this circumstance, the outdoor temperature is even more important, as venting won’t help you when it’s 32°C outside. We also often fail to consider the heat load created by the other equipment in our garden. Ballasts, for instance, are big contributors to overheating. Magnetic ballasts create approximately 3,500 BTU of heat and digital ballasts create about 2,500 BTU per 1,000 W. The most energy-efficient solution for ballasts is to keep them out of the garden entirely—while you don’t want them baking, it’s just not necessary to keep them at the comfortable temperature you’re probably shooting for in the garden, so there’s no need to expend the same amount of cooling energy as you do in the garden to offset their heat load. If it’s not possible to get them out of the garden, you must account for their heat production when you size your cooling system.

Maximum Yield Canada | November/December 2012

CO2 generators are also a huge contributor to the garden’s heat load. The BTU rating on your generator is a “per hour” rating, so if it’s capable of 12,000 BTU per hour but is only running for 15 minutes an hour, it will produce 3,000 BTU of heat per hour. Most manufacturers of CO2 generators will have a chart available that will help you determine how often your generator will run and therefore how much heat it will produce. Water-cooled CO2 generators are also available; these can be used in a drainto-waste capacity or on a chiller and recirculating pump. In these units, most of the heat produced by the flame is removed by the water, which reduces the heat load on the climate control system dramatically. As mentioned, air cooling your reflectors or venting your garden will affect the run time and heat production of any CO2 generator. Outdoor climate will be a consideration for you no matter what your circumstances. When it’s really hot outside, your garden will need a certain amount of air conditioning regardless of whether you have equipment running or not. Most manufacturers of cooling equipment will provide reference materials to assist you with determining the amount of heat that must be removed from the garden even when no equipment is running (the ambient heat load). In cooler climates where the temperature stays moderate all year, this is often not an issue, but in warmer climates, seasonal outdoor temperatures are a big consideration. Your garden’s ambient heat load number is going to be arrived at by calculating a combination of square metres, insulation quality and the average high outdoor temperature. Consider also that the hotter it is outside, the less efficiently most air conditioners will run—the same is true of chillers in watercooled applications, but to a much lesser extent.

Humidity Humidity is also a big factor in the health and success of your crop. Humidity levels that are too high will give certain fungi a perfect breeding environment, which will in turn result in a less-healthy plant and a smaller—and usually lower-quality—harvest. Humidity levels that are too low will often result in rapid transpiration of moisture by your plants, which will usually result in reduced nutrient uptake. Gardens by their nature are generally humid environments, so the addition of humidity is usually only necessary in exceptionally dry environments—high humidity is a much more common problem. When venting or air cooling, the humidity outside

is going to have a direct effect on the humidity inside the garden. If you’re striving to maintain a humidity level "Chiller systems are extremely of 50% and you introduce air that’s energy-efficient alternatives for 90% humidity, you have to offset that climate control." somehow. Gardeners in moderate or humid environments nearly always have to use a dehumidifier in the garden. Dehumidifiers are also a source of heat (usually anywhere from 1,000 BTU to 5,000 BTU per hour, depending on the continues, the dreaded size of the dehumidifier and the amount of time it’s running), pathogen pythium is so this will need to be considered when the cooling system is the usual result. being sized. Liquid cooled dehumidifiers are available as well. If the garden is warmer All air conditioning and chiller systems will dehumidify than the recommended to some extent, but if you’re able to maintain the humidity nutrient solution temperatures where you want it with lights on using only the a/c or for your application, a nutrient chiller, the humidity will build quickly during the lights-off chiller will need to be employed. cycle because the cooling system doesn’t need to operate as If you’re using a standard a/c, the chiller is a separate frequently; less dehumidification will occur as a result. For piece of equipment that must be accounted for as part of gardeners who prefer not to use a separate dehumidifier, the heat load when sizing the a/c system—unless you’re some air conditioning systems are available with a 24-hour able to keep it outside the garden—because all of the heat dehumidification option, which utilizes a heater in being removed from your nutrient reservoir is eventually conjunction with the a/c system to achieve dehumidification exhausting out the back of your chiller. Complete water without adding cooling. These same options are also cooling systems are available that will allow you to utilize a usually available in chiller systems, as well as an “extended” single chiller to control both the climate in the garden (or dehumidification option, which utilizes a thermostat in gardens) and maintain the proper nutrient temperature conjunction with a humidistat for tighter control. as well. If you are utilizing a water-cooled CO2 generator, this can be incorporated into the single chiller system too. Nutrients Chiller systems are extremely energy-efficient alternatives for climate control. In hydroponic applications, maintaining the correct nutrient temperature is absolutely vital. A certain amount of dissolved What you’re doing when you cultivate a garden indoors is oxygen is necessary to maintain the health of your plant’s trying to create the perfect environment for your plants to roots and its ability to uptake nutrients—if the nutrient thrive. In order to be successful—regardless of what you temperatures get too warm, the level of dissolved oxygen grow—each gardener’s specific environmental challenges in the nutrient solution goes down, which results in slower must be considered and overcome. As long as you take nutrient uptake by the plant. Compounding this problem is into account all the relevant factors, you can eventually the fact that the warmer the nutrient water temperature, the achieve that perfect climate. And if the climate is perfect more dissolved oxygen the plants need for proper nutrient for your plants, that perfect harvest will finally be within uptake—so they require more dissolved oxygen in this your reach. circumstance, but they’re actually getting less. If the problem

Maximum Yield Canada | November/December 2012

Perfecting the System by Lee McCall

Lee McCall walks us through the set-up for a comprehensive new growing system that he thinks just might be the start of something big in the grow biz.

Maximum Yield Canadaâ&#x20AC;&#x201A;|â&#x20AC;&#x201A;November/December 2012

We’re at the beginning of a very exciting time in the hydroponic industry—and although the concept of delivering custom-tailored, high-performance nutrients directly to your plants in precise proportions with exact timing in an ideal environment featuring the most advanced horticultural technologies is not really new, it does seem like more knowledge surfaces daily. Every new breakthrough in technology encourages more individuals to invest their time and money into what is now a blooming industry worldwide. This chain reaction is the industrial revolution of our market—and these crucial years will change the way we grow from here on out. Let’s talk about plants and gardening. Recently, a new friend introduced me to a brilliant concept that combines all the micro-worlds of growing into one seamless system,

“ Recently, a new friend introduced me to a brilliant concept that combines all the micro-worlds of growing into one seamless system, compatible with both soil and hydroponic gardens.” compatible with both soil and hydroponic gardens. This is the first growing style that I can truly say is both simple and advanced—meaning the method employs simple tactics in a systematic series that allows for advanced technical results. Starting with clones or cuttings, the new method uses an automated cloning machine to initiate root production.

Instead of dipping the clone into a gel, try a liquid concentrate of NPK, B vitamins and hypochlorous acid. Maximum Yield Canada | November/December 2012

Perfecting the system Neoprene inserts were used in this case, but net cups and plugs will also work. The application of B1 vitamins is also recommended for cloning stages as it reduces the effects of shock on newly spliced cuttings. B vitamins can be applied either by way of root drench or foliar spray approximately 24 hours prior to taking new clones off the selected parent plant. After the cutting has been separated from its host, the bottom portion of the clone is dipped into a liquid concentrate with a mild NPK of .009 to .011 and B vitamins in conjunction with a hypochlorous acid additive. These two products are diluted into a simple millilitre-per-4-L solution in order to fill the clone machine reservoir. Clones should then be placed immediately into either a holding container with the solution or directly into the plugged-in clone machine—the light solution of nutrition and sterilizing agents helps encourage healthy growth, reduce stress, deflect negative pathogens from infecting the clones and prevent

“ A fairly small amount of space is all that is needed to produce a healthy group of pre-vegetative clones.” yellowing in the plant once the cuttings have callused or begun to root. Generally, the rooting phase (from the time they are cut) can take anywhere from five to 10 days before the plant is mature enough to transplant into its first week of a vegetative growth cycle. Cloning machines do not necessarily work better than tray-and-dome methods with plugs, but for larger-scale operations involving higher plant counts, they definitely consolidate the risk on a broad spectrum in terms of propagation maintenance—rather than having to check multiple tray-anddome set-ups to ensure consistency among each

A dilute nutrient solution is recommended for young clones, so measure before you transplant and measure often. 50

Maximum Yield Canada | November/December 2012

Proper temperature and humidity levels will dictate success regardless of the method used for starting clones.

individual group of clones, the automated machine forces the clones to all have the same root zone conditions. Overall, however, proper temperature and humidity levels will dictate success no matter which method is used. Once properly rooted, the small cuttings are transplanted into small 7.62-cm net cups with hydroton and light expanded clay aggregate (LECA) and placed into a floodand-drain or ebb-and-flow system. Make sure to always thoroughly rinse off clay growing media before introducing it to new plants. Here they can marinate in an in-between— or pre-vegetative stage—and build up structural support before a final transplant into the primary growth medium or hydroponic system. A and B or three-part nutrient systems are great candidates for this stage in development; these nutrients will stimulate fresh and aggressive growth from the newly transplanted cuttings without drastically shocking them while they are still young and fresh out of the cloner. A very dilute solution is recommended at first in order to see how the new clones respond to immediately available plant food. This preliminary vegetative stage basically supercharges your rooted clones into vibrant 20.32- to 30.48-cm plants that should now easily transplant into any growing medium or system with virtually no slowing in growth. A fairly small amount of space is all that is needed to produce a healthy group of pre-vegetative clones. After your plants achieve the desired height, the small net cups holding the roots and containing the hydroton can then be transplanted right into organic soil mixes in 7.58-L containers, cup and all—there is no need to remove them. During this transplanting phase, a select granular blend of endomycorrhizal fungi, kelp extract, humic acid and a few bacillus strains should be inoculated into the plants’ systems by placing the net cups directly on top of a small amount of the mix in each transplanting hole. The beneficial microbes will help the plants absorb water and nutrients at an accelerated rate. Some of the pre-veg net cup clones should

nutrients that stimulate microbial activity in and around the root system. The end result is impressive: you’ll see enhanced aromatic properties stemming from the increased essential oil production that fruits, flowers and vegetables exhibit when they are introduced to high-quality organic elements like molasses, cold-pressed kelp, guano, worm castings and glacial rock dust. Perhaps some of the salts or heavy metals found in the synthetic nutrients decrease microbe activity, but the organics being reintroduced on a consistent basis help balance out the plant system in a way that allows for enhanced nutritional uptake from multiple sources. Hydroponic reservoirs are initially filled up with the synthetic

“ This preliminary vegetative stage basically supercharges your rooted clones.”

Rooted cuttings can marinate in a flood-and-drain or ebb-and-flow system and build up structural support.

also be transplanted into the same 7.58-L containers, but placed in silica rock for continued flood-and-drain systems that will finish out the plant cycle. The new ebb-and-flow transplants are not left un-inoculated because they will be hydroponically grown—they receive the same inoculated mix, but in a finer grade that allows it to be mixed directly into the hydroponic solution and applied with the first feeding after being transplanted. This nutrient system is especially intriguing to me because it combines all the performance benefits of synthetic base nutrient systems in a cycle with premium, organic-base

nutrient system and, as the water level decreases from plant uptake, they are then topped off with the organic solutions. Approximately every 10 to 14 days, the reservoir should be drained and completely sprayed out and the cycle restarts. The soil plants will generally alternate between organic and synthetic feedings on an as-needed basis. Different varieties of plants will require more watering than others, so spot-check each plant if possible to ensure it is ready for a drink and that you are not overwatering. This system, though simple enough, was custom tailored for a specific individual in order to meet their large-scale growing needs. After years of hobby gardening, greenhouse and big agriculture developments in horticulture, systems of this nature are revolutionizing the process again—just when you thought you had seen it all, the industry sprouts a new root that looks like it will branch into another dense network of niche markets. More products, more gardens, more growers and healthier plants—all these mean that our industry is continuing to grow and mature as we head into the future.

Maximum Yield Canada | November/December 2012

MIXING YOUR

GROW MEDIUMS by Chad Garbet

No one wants to grow their plants in poor soil. However, even if you have the best soil, you can always add certain things—or mix together mediums— to help your plants grow. Everyone strives to get the best soil to grow the best plants, but there is always a way to make it even better. Improving soil is called soil conditioning or soil amending. Some conditioners that improve plant growth include lime, peat, diatomaceous earth, clay, vermiculite, hydrogel and shredded bark, which all increase the water retention. Conditioners that add to the soil’s nutrients include manure and composts. I make a special mix of soil, and it works wonders for my soil plants. The soil I use is usually a general purpose mix. Then I add all my fertilizers, such as black worm castings, kelp, seaweed and some powdered minerals. This is to make sure the soil has a good nutrient value for plants. Also, the organic fertilizers will take a while to breakdown, so the plant will be fed slowly over a period of time. The water retention is the next step, and rocks are an easy fix for that. I prefer to use diatomaceous earth, a porous, silica-rich stone that retains

Maximum Yield Canada | November/December 2012

water and helps drain it too. My mix also contains another water retention aid: coco coir. Coco coir has great drainage and keeps perfect water retention, as well as helps hold in precious nutrient values while keeping the soil aerated. All in all, the ratio I use to about 50% soil and fertilizer mix, 25% diatomaceous earth and 25% coco coir. I have never seen soil-based tomato plants grow so fast and lush as they do in this mix, and I have used a lot of different soil throughout my gardening lifetime. Growing a soil garden in the summer is always a great escape from everyday life. Build a small getaway, let your plants flourish in the soil mix and you will have a lush jungle or some vigorous veggies in no time. Just remember that the nutrients in the soil deplete, so try to stay on top of fertilizing the soil and to turn the soil over after your garden is done for the winter and again in early spring.

This will keep the soil aerated and help distribute the nutrients evenly throughout the soil mix. Hydroponics also has a pretty big list of grow mediums, including diatomaceous earth, coco coir, coco polymer, rockwool, clay pebble and perlite. These mediums are all usually used alone; however, strange combinations are always fun to try (it’s important to have fun while you garden). That being said, knowing about growing mediums before doing so is always a good idea—you can’t be too sure before putting seedlings into a medium. The hydroponic grow medium that I prefer is a form of diatomaceous earth. Its high silicate content is a major benefit to plant cellular structure, and it has very good water retention. It’s also a natural pesticide that causes pests to dehydrate. My second choice is coco polymer. While it’s usually a bit unstable and plants can have a habit of falling right over, polymer holds perfect moisture retention—not too wet and not too dry—that is perfect

“All growing mediums have benefits and downfalls. This is why some gardeners like to mix things up.” for plant growth. If you try mixing the polymer with the diatomaceous earth, you will find it doesn’t mix very well (all the rocks will fall to the bottom and the polymer will come out on top). There is a solution to this, however; using equal amounts of each medium, first put down a layer of polymer, then a layer of diatomaceous earth, followed by more polymer and finally finishing with more diatomaceous earth on the top. This builds “shelves” for the roots to expand into the coco polymer, resulting in huge healthy root masses. All growing mediums have benefits and downfalls. This is why some gardeners like to mix things up (some people have even tried soil with hydroponics). There is no limit to the combinations. Taking the time to make the best grow mediums always pays off in the end; experimenting with grow mediums can help expand one’s garden knowledge and lead to the greatest garden ever grown. It’s also fun to try new things, even though they sound a bit out to lunch. Try something bold and make your own mix, and enter the world of the new and strange; you might find you quite like it. MY

Maximum Yield Canada | November/December 2012

Ocean of

Air by Grubbycup

Outdoors, plants live in an ever-moving ocean of air; however, once they’re brought inside, gardeners must find a way to replace this lifesustaining breeze. An ocean of air washes over and through plants that are grown in a natural setting, such as a meadow. Tides of air currents even out the environment; they normalize temperature and humidity, wipe away excess oxygen and bring in needed carbon dioxide (CO2). When a plant is brought indoors, however, this free flow of air is cut off by walls. Plants grown in still air tend to sit in a cloud of oxygen—thus, not receiving enough CO2—and have more problems with moulds and insects. However, a good gardener will replace what is lost—in this case, moving air. Moving air helps dry excess moisture before it

Maximum Yield Canada | November/December 2012

goes stale or encourages mould spore growth. In a garden, nothing good grows in stagnant water. As such, there must be enough air circulation to dry out spills and excess moisture to maintain a healthy growroom. Moving air is also useful in controlling a growroom’s temperature. When lowering your room’s temperature, it is often more efficient to vent off the hot air than try to dilute it with cold air. Also, try to remove the hot air close to the heat source so it can’t transfer much of its heat to the rest of the surrounding environment. For example, a 1,000 W HID light puts out a lot of energy, and passing the heated air though a vented hood can quickly remove it from the room. In an ideal situation for cooling, outside air is brought in, run through ductwork to the hood, passed through the hood and returned by ducting to the outside. The first fan in the system should either be connected to the light hood or at least be near the lamp to remove the worst of the waste heat. When designing your ducting, keep in mind that wide turns are

better than sharp turns and that the hot air you are trying to get rid of rises. Also, it is best to run the ballast outside the garden so its heat doesn’t contribute to the overall room temperature. If the heat from the lights can be dealt with, then ambient room environment can be controlled with much less effort. If the area needs additional cooling, vent off the air from the hottest part of the room. Depending on how airtight the garden is, a passive air vent might be required to replace the vented hot air. This incoming air should be taken from a cool source—for example, cooler outside air or air-conditioned cold air. Solar-powered fans can also be used to give an extra boost to ventilation systems during the hottest part of the day without adding to your electric bill (if needed, this should be the second fan in the system). Speaking of fans, in a basic three fan set-up the first fan should vent the lights, the second should vent the garden and the third should circulate the air within the garden. Keep in mind the room itself needs air circulation as well, both to encourage evaporation and to supply fresh CO2. CO2 is sometimes added to the environment artificially, although my preference is for the gardener—

who is as much a part of the system as anything else—to spend time in the garden and contribute breath to the system. (If you think your garden isn’t getting enough CO2, consider bringing a friend in and do some breathing together. Human beings are fairly large animals and generate quite a bit of carbon dioxide when exercising.) To calculate how many cubic metres per minute (m3/min) of ventilation you need, calculate the size of the room in cubic metres by multiplying the height, length and width of the room. For example, a 2 m by 3 m by 3 m room is 18 sq m. A single 18 m3/min fan would move the room’s area worth of air every minute, and a 9 m3/min fan would do the same every other minute. Fans are usually rated at a low load, so ducting will reduce m3/min dramatically. Every situation is different, and common sense must be used. In a cold winter room, heat retention might be more important than removing waste heat. We live in an ocean of air, complete with currents, flow and volume. By giving plant the fresh air and airflow they need, not only will the plants be happier, but it can help keep moulds and moisture-loving insects like fungus gnats at bay.

Maximum Yield Canada | November/December 2012

by Dr. Lynette Morgan

Photosynthesis,

Maximized.

Dr. Morgan explains just how much light your indoor garden needs. 56

Maximum Yield Canadaâ&#x20AC;&#x201A;|â&#x20AC;&#x201A;November/December 2012

Photosynthesis is the process that drives plant growth and development, and while most of us have some idea of its importance, there is a lot to understand if we are to fully optimize the potential of our plants. We all know plants need light and this radiation energy—as light is technically known—can either be supplied by the sun or artificially, by the highly efficient grow lamps used by indoor gardeners and the plant scientists who study photosynthesis. However, it is not just the light source that affects the rate of photosynthesis—there are a number of external and internal plant factors that influence the production of sugars for plant growth as well. Maximizing all the variables that play a role in photosynthesis at the same time can lead to some fantastic growth rates, but it takes a little understanding of plant physiology to get things just right.

What is photosynthesis? The basic principle behind photosynthesis is fairly well understood—light energy is used to synthesize sugars (or, assimilate) from carbon dioxide and water. Light is absorbed by pigments in plants—the most common being chlorophyll— and energy provided by light is used to combine hydrogen (H) from water (H2O) with carbon dioxide (CO2) from the air to form sugars, such as glucose (C6H12O6). The energy from light is stored within the sugar molecules, which are then also used as a raw material for the synthesis of many other compounds required by the plant for growth and development. Photosynthesis is actually a very complex biochemical process involving many different enzymes; however, the simplified equation looks like this:

6CO2 + 6H2O in the presence of light turns to C6H12O6 + 6O2 (oxygen)

Ideally,

all the plants in the growing area should receive sufficient light to allow them to reach a point termed light saturation— that is, the point when further amounts of light don’t provide any additional increase in photosynthesis.” Maximum Yield Canada | November/December 2012

photosynthesis, maximized.

Indoor lighting can be used to grow a wide range of plants.

In the equation above, we can see that plants need not only a light source of sufficient intensity and the correct wavelengths for photosynthesis, but also a supply of CO2 and H2O. What the equation doesn’t tell us is that other factors play a role in the rate of this process as well—temperature, for example, determines the rate of photosynthesis; the nutritional status of the plant affects light harvesting; leaf area and plant pigments, such as chlorophyll, determine how much light can be intercepted; and stomata apertures influence the flow of CO2 into the leaf. Just to complicate matters even more, the internal flow of water required for photosynthesis into the leaf can be affected by drought, high EC, root damage and other factors, while CO2 levels directly around the leaf surface are affected by airflow and the use of CO2 enrichment. light

additional increase in photosynthesis. However, what usually occurs is that most of the plants will remain at a point below the light saturation level, as leaves and plants end up shading each other as they grow and develop.

Not enough and too much light for photosynthesis

A common situation in indoor gardens is insufficient light for photosynthesis. This is often because too many plants end up crammed into a small space—plant hoarding is, after all, pretty common with gardening enthusiasts—or because small plants have rapidly become large mature ones, filling intensities the available area with dense will break down foliage. In this type of situation, How much light is needed photosynthesis is limited by light chlorophyll, for photosynthesis? availability and if the situation is imparting a white, severe, the crop might even fall Most indoor growers sooner or later have to so far below the light saturation grapple with the concept of how much light bleached appearance point that it reaches what is needs to be provided for maximum plant to the leaves and termed the light compensation photosynthesis. There is no hard and fast resulting in a point. This is where the energy rule for this, as different plant species have gained from photosynthesis various optimal light-level requirements. A decreased ability equals that lost in the process of densely planted growing area will need a to carry out respiration so that no net growth higher light input than a sparsely planted can occur. Between the light photosynthesis.” one and plants’ requirements for light compensation point and light tend to change from seedling through saturation point, any increase in to maturity. Ideally, all the plants in the light will increase the rate of growth; growing area should receive sufficient light to however, the ideal situation is to remain closer to allow them to reach a point termed light saturation—that light saturation than light compensation. is, the point when further amounts of light don’t provide any

Very high

Maximum Yield Canada | November/December 2012

Having too much light for photosynthesis can occur in indoor gardens as well—more commonly with younger plants or with those that have been grown under lower light and then planted out under a greater light intensity. Very high light intensities will break down chlorophyll, imparting a white, bleached appearance to the leaves and resulting in a decreased ability to carry out photosynthesis.

In a test

tube, it is true that chlorophyll a and b strongly absorb red and blue light and reflect yellow and green, but inside plant tissues things are different.”

Limiting factors In an indoor garden, the most likely limiting factors for photosynthesis—apart from a lack of light intensity or light of unsuitable wavelengths—are the availability of CO2 and temperature control. If temperatures become too high, plants will effectively shut down photosynthesis as the stomata (pores in the leaf that allow gas exchange) close to conserve moisture and prevent desiccation. Closed stomata prevent CO2 from the air diffusing into the leaf and so photosynthesis will stop. Low temperatures have a similar effect since the rate of enzyme reactions within a plant is temperature dependent, photosynthesis will slow when conditions are cooler than optimal and will be most rapid

High density and overcrowding of plants lowers light penetration and overall plant photosynthesis.

when temperatures are ideal for the particular plant species being grown. Carbon dioxide is also a limiting factor—particularly in enclosed indoor growing spaces—and CO2 depletion in densely planted indoor gardens or even in closed greenhouses is common. Plants can rapidly strip CO2 from the air surrounding their leaves under good light conditions when high rates of the gas are being utilized for photosynthesis. Since CO2 is only naturally present in the air at rates of 390 ppm, fresh supplies will need to be vented into the area or CO2 enrichment supplied. Many growers opt to enrich the air with CO2 up to levels of 1,400 ppm as this is proven to boost photosynthesis and growth in most plant species; however, very high levels of CO2 can cause plant damage and should be avoided—enriching with CO2 above 1,400 ppm for most crops does not tend to give any increase in photosynthesis in the long term anyway. For growers without CO2 enrichment, ensuring there is sufficient ventilation to remove stale air and pull in fresh air to replenish CO2 levels in the indoor garden is vital for photosynthesis and the rate of this air exchange is often much higher than many growers realize.

Photosynthesis with artificial lighting

Measurement of light is an important factor when aiming to optimize photosynthesis in an indoor garden.

When light hits the surface of a plant, some is reflected back to the environment and some is transmitted through the leaf, but most is absorbed by the pigments in the leaf cells. The best-known light-absorbing pigments are green chlorophyll a and chlorophyll b. However, these are not the only lightharvesting pigments in plants—there are also a number of accessory pigments, which allow photosynthesis to use quite a large proportion of the visible light spectrum. Some of Maximum Yield Canada | November/December 2012

photosynthesis, maximized.

these light-absorbing pigments are the xanthophylls, the carotenoids, lutein and lycopene and the number and ratios of these within the plant cells vary between different plant species. all these factors If we look back at the history of plant will allow plants to lighting for indoor gardening, in the take full advantage early days the light-absorption spectrum of those cellular was commonly displayed as peaks for reactions, which chlorophyll a and b (see Figure 1). provide both energy These two peaks are in the red and blue wavelength ranges. Thanks to this and assimilate for sort of graph, an assumption was often maximum growth and made that providing full-spectrum development.” light with wavelengths in the green and yellow bands would just be a waste of energy since there are narrow bands in the red and blue wavelengths doing all the work as far as photosynthesis goes. However, there is a major problem with using this sort of information—this graph shows what happens when these two pigments, chlorophyll a and b, are isolated in a test tube and not how they act within a complete plant system. In a test tube, it is true that chlorophyll a and Chlorophyll, which gives many plants a green colour, is not the only b strongly absorb red and blue light and reflect yellow and pigment that can absorb light; red plants use a range of different green, but inside plant tissues things are different. pigments to harvest light. Figure 2 is a graph we should be more familiar with these

Providing

Chlorophyll b Chlorophyll a

380

430

480

530

580

630

680

Wavelength (nm)

Figure 1: Absorption spectrum for chlorophyll a and b in vitro

days as it reflects actual photosynthesis inside plant tissue— not what happens in a test tube, as was shown in Figure 1. There is still a peak in the blue and red wavelengths, but there is much more photosynthesis going on in the 500 to 600 wavelength band—the green and yellow area—than we generally recognize. Obviously plants do reflect more green light, which is why foliage looks green to us; however, there are pigments present in the plant trapping this green light and passing the energy on to chlorophyll for photosynthesis, so green light still drives the process. This graph is an average response taken from a large number of common plant species, so it reflects accurately what occurs in most crops. It shows that the role of green and yellow light in triggering photosynthesis inside plant tissue is actually surprisingly 60

Maximum Yield Canada | November/December 2012

important. The reason behind this is that chlorophyll is not the only pigment that can absorb light—there is a range of other accessory or antenna pigments that use green and yellow light as well. For example, much of the photosynthesis occurring in the green waveband (540 nm) results from absorption by active carotenoids. Many of the light-harvesting pigments also make use of a wide range of light wavelengths and pass the energy on to chlorophyll for photosynthesis. So, while chlorophyll itself might not absorb much in the way of green or yellow light, other pigments can—and the entire spectrum can then be used by the plant. The use of accessory pigments allows photosynthesis to use a large proportion of the spectrum—not just red and blue wavelengths—and that’s an exciting opportunity for indoor growers to take advantage of. Photosynthetic Action Spectrum 100 90 80

Relative Net Photosynthesis (%)

Absorption Spectra of Chlorophylls a and b

70 60 50 40 30 20 10 0 350

380

400

450

480

500

550

600

650

690

700

Wavelength (nm)

Figure 2: The effect of different wavelengths on photosynthesis

710

The Emerson Enhancement Effect and photosynthetic lighting While it’s commonly known that there are a wide range of wavelengths absorbed and used by plants for photosynthesis, the enhancement effects of certain bands of the spectrum are more complex, but still important for indoor growers wanting to maximize photosynthetic growth effects from their lighting to consider. Some of the shorter light wavelengths—when combined with longer wavelengths—act to boost photosynthesis more effectively than if either of the wavelengths was present alone. This is termed the Emerson Enhancement Effect and it is an important aspect to take into consideration when deciding between different types and outputs of lamps and bulbs. Photosystems 1 and 2, and the Emerson Enhancement Effect Net Effect Photosystem II

Absorption / Activity

Photosystem I

300

400

500

600

700

800

Wavelength (nm)

Figure 3: The Emerson Enhancement Effect

This enhancement effect means there is a synergy between red and far red wavelengths and, therefore, a benefit to providing plants with both—even if the plants are not flowering. Figure 3 below shows how the Emerson Enhancement Effect works—up at the 700 nm range, it appears as if photosynthesis drops off (this is called the red drop off), so it might appear that there is no point in providing plants with light in this waveband. However, when wavelengths in this far red range are combined with the shorter wavelengths of red light (680 nm), a photosynthetic enhancement effect occurs. This is why we have begun to see more lighting bulbs developed featuring output in this far red range, allowing indoor plants to take advantage of a fuller spectrum in the same way that outdoor plants have always been able to do.

Maximizing the photosynthetic potential indoors Maximizing photosynthesis in an indoor garden is dependent on a number of factors: the correct wavelength spectrum (as explained earlier, these days that means fullspectrum lamp outputs), sufficient intensity of light for the

There are a wide range of wavelengths absorbed and used by plants for photosynthesis.

stage of plant development, CO2 replacement or enrichment to levels over 1,000 ppm, sufficient warmth to maximize the rate of photosynthesis, good rates of water uptake and cell turgor, overall plant health and sufficient nutrition. Providing all these factors will allow plants to take full advantage of those cellular reactions, which provide both energy and assimilate for maximum growth and development. Maximum Yield Canada | November/December 2012

Small Space Oasis:

Gardening for

Apartmentdwellers by Kristen McKenzie

Even though apartments have little or no space for gardening, that doesn’t mean people who live in them can’t grow plants. Here are a few tips on how to turn a tiny space into a green oasis…

Maximum Yield Canada | November/December 2012

As real estate prices soar and space becomes sparser, more and more people are turning to rental units within apartment complexes— residences that often have little to no yard space for gardening. But that doesn’t mean apartment-dwellers can’t still enjoy growing their own flowers, shrubs and produce. Matthew Carroll, spokesperson for Nursery and Gardening Industry Australia, says more and more apartment folk are finding ways to create their own little garden havens despite the limited space. It just takes a little time, creativity and imagination. “There are definitely space wars going on,” he says. “But there’s plenty of ways to integrate green space into people’s lives.” Here are some of his top suggestions for creating an apartment-friendly garden retreat.

Say hello to herbs

Even apartment-dwellers can reap the benefits of growing fresh food, flowers and herbs.

Carroll says herb gardens have become a trend among urban dwellers and it’s not hard to see why: they’re easy to maintain and can be grown indoors in a variety of tight spaces. Moreover, they’re visually appealing, aromatic and can make a great addition to any recipe. Even if you don’t have a balcony, herbs can still thrive on a windowsill or kitchen counter. All that’s really required for success is regular watering and adequate access to sunlight. And to make things extra simple, ready-to-grow herb kits are available for sale at a number of garden centres and nurseries. Tip: some of the easier herbs to start with are chive and parsley, as they both require less light than other varieties.

“If you pair the right plant with the right pot, you can minimize your upkeep.” Your local garden centre will be able to advise on which numerous plants or seeds are suitable for indoor potting. In addition to growing an appealing array of flowers and houseplants, Carroll recommends trying out dwarf varieties of crops that will produce smaller fruits and vegetables, but still yield great results from pots and smaller garden spaces. These include apples, quince, cherries, peaches, plums, figs, avocadoes and blueberries.

Get passionate about pots

Think vertical

“Container gardening has become more and more popular,” Carroll says, adding there are now new varieties of stylish, lightweight products available for purchase.

“If you don’t have a lot of floor space, you can take [your plants] up the wall,” Carroll says, referring to the hot new trend of vertical gardening systems.

The most innovative and aesthetically pleasing of these systems is the greenwall, a soilless, vertical patch of garden that grows along the flat surface of a structure. The plants used for greenwalls are those that can adapt and survive in difficult growing conditions, including ferns, grasses, herbs and perennials like the begonia. You can get tricks and tips on how to create your own greenwall at your local nursery centre. There are also many landscaping companies that have begun specializing in these visually stunning gardens. An alternative to the greenwall is to espalier, a vertical gardening method in which a lattice or wire provides support for branches and offshoots, so they can continue to grow upwards. Finally, there’s always the trusty hanging basket, a space-saving gem that grows a variety of plants and flowers and even certain edible crops.

Maximum Yield Canada | November/December 2012

You tell us What is the Controller, why are three-part nutrient systems better than one- or two-part, and why are there explosions coming from the lab? Adam Hanscom, sales manager at General Hydroponics, answers these questions and more for Maximum Yield.

GENERAL HYDROPONICS

Founder of General Hydroponics, Lawrence Brooke

Maximum Yield: Tell us a little of your company history. Adam Hanscom: General Hydroponics (GH) was founded over 35 years ago by Lawrence Brooke. Lawrence’s inspiration for his first hydroponic system was a mountain stream and the plants thriving beside it. This system was prototyped and GH began. Lawrence forged relationships with renowned botanists and chemists while attending UC Berkeley in the 1970s. Cal Hermann was one of Lawrence’s colleagues during that time, and he is still the head chemist for the company today. GH’s legendary pH stability was also developed in those early years of university research. And the UC system—where it all began— continues to test GH’s formulas in their state-of-the-art research centers at UC Davis and Berkeley. Situated in the heart of Sonoma County, California, GH sits on 10 beautiful, sun-drenched acres. When visitors come to our facilities, they are greeted by our soccer field, greenhouses and our hydroponically grown roses. The warehouse and production factory is a 45,000-sq.-ft., state-of-the-art industrial space with a roof covered in a multi-million-dollar solar array. The massive greenhouses are filled with plants—basil, lettuce, peppers, tomatoes, sunflowers and more—for testing systems and nutrients. Impressive ornamentals are grown there as well. Behind the greenhouses, GH also grows everything from giant pumpkins to a ¼-acre of delicious strawberries in the lush soil. GH is proud of its tradition of bringing nature and technology together. GH will always continue to strive for quality, simplicity, innovation and a sustainable future. MY: What is your company’s philosophy? AH: Sustainability, quality, simplicity and innovation: these four words reflect our commitment to our customers, our families and our planet. They have been our guide to growth and will continue to lead GH into the future.

Maximum Yield Canada | November/December 2012

Sustainability, quality, simplicity and innovation: these four words reflect our commitment to our customers, our families and our planet.”

MY: What is your most popular product? Why do you think this is? AH: Flora Series is without question our most popular product. Growers choose Flora Series because it has consistently produced top-quality results for over 35 years. It’s cost-effective, reliable and available in all hydro shops across the country. MY: What types of products are available in your General Organics (GO) line? AH: The GO line consists of two single-part base nutrients, BioThrive Grow and BioThrive Bloom. To compliment BioThrive are seven supplements: BioRoot is a digested compost tea, Bioweed is a veryhigh-quality seaweed/kelp extract, BioBud is the line’s flower booster, Diamond Black is a soil-building humic acid and CaMg+ is a natural source of calcium and magnesium. Then there is Bio Marine, a cold-processed squid emulsion that can be used as both a standalone fertilizer and a supplement to BioThrive Grow and Bloom. Last, but not least, is Ancient Forest soil amendment, which is composed of an incredibly diverse array of microorganisms. MY: For beginner gardeners in colder climates, what are your basic nutrient and supplement recommendations for a successful garden? For more advanced gardeners? AH: One of the greatest advantages of indoor gardening is being able to control the growing environment. GH publishes feed programs for gardeners ranging from greenhorns to green thumbs. Our simple programs allow minimal inputs with proven success. Our expert programs utilize more products that provide additional benefits to both soils and plants. MY: What is the Controller, and what does it do? AH: GH’s Controllers consist of two connected reservoirs that help ensure an ideal nutrient level is maintained in

hydroponic systems. The Controller is the reservoir that sits on the bottom and has a float valve connected to a line of growing units. The Master Reservoir sits on top of the Controller and holds additional nutrient solution. As plants draw water from their individual reservoirs, the liquid levels drop, which causes the float valve in the Controller to open and draw fresh nutrient solution from the Master Reservoir above. This automatically maintains the ideal nutrient solution level in all connected units. MY: Why are there three parts to the General Hydroponics Flora Series nutrients? What are the benefits of a three-part nutrient system versus a one- or two-part? AH: There are a few reasons why Flora Series has three parts. The most important to note is the diversity of nutrient profiles and the great flexibility to use the products with all plants because the nutrients are separated and can be blended in so many different ways. With a two-part, you have a lesser ability to do so, and with a single-part, the only thing that can change is overall concentration of the finished nutrient. MY: Are your products designed for use in hydroponic systems only? AH: GH produces many products, including quality hydroponic systems. All GH’s fertilizers and supplements can be used in all growing systems, not just hydro. MY: Is there anything exciting happening in the R&D stage that you are at liberty to tell us about? AH: Yes, there are always exciting developments and crazy experiments going on in our R&D department. They never tell us sales guys about them until they crawl out of the catacombs, exhausted and near death from working so hard. I personally haven’t seen anyone from R&D for about six months, but the explosions in the lab have subsided and we expect new products to emerge any day now. Maximum Yield Canada | November/December 2012

talking shop

AT A GLANCE

Company:

Hygro Gardening Supplies Inc.

Owner:

Christa Fernau

Hygro Gardening

Location:

1791 Tamarac St. Campbell River, B.C. V9W 5Y7

Phone:

1-250-286-0424

Email:

treetop1791@shaw.ca

Maximum Yield Canada | November/December 2012

Supplies Inc.

I got into this industry because of my background in greenhouses and everything to do with growing. During my years in forestry, I learned about propagation, watering, fertilizing, breeding trees, planting and nurturing seedlings in greenhouses. I was immersed in growing at every level, and was fortunate to be able to take courses on pesticides, native plants and greenhouse management. I even took courses on ergonomics. With government cutbacks, however, I started to see important programs being cut in forestry. I also didn’t like the constant insecurity of my job. I was a single mom raising two daughters and being laid off every season, not knowing if I was being called back, was wearing on me. So, I left forestry and took a temporary job as a salesperson for a hydroponic company (much thanks to the help of my awesome sister, who owns Duncan Plants and Ponics). Selling nutrients to hydroponic stores was fun and pretty easy compared to the physically hard work I was used to. I soon decided to start my own business in beautiful Campbell River, where there was no immediate competition at the time. Hygro Gardening Supplies Inc. has been running for almost 10 years now. There have been a lot of challenges along the way, but also some great experiences. In the beginning, I was living on my piece of raw and rugged land on the north end of Quadra Island—I actually lived in a tent for quite a few months until I had enough money for building a home. During those days, I remember getting on the little ferry every day for my hike to work feeling pretty dishevelled beside the women commuting to their bank and teaching jobs. It also took a while to get established and get to know

my customer base. The most difficult thing, however, was constantly being away from my family because I needed to keep the shop running. Still, I soon found myself connecting with some amazing people in Campbell River. I remain grateful for my early loyal and patient customers who believed in me and supported me during the learning curves of running a store. Also, I’m grateful for the patience and trust of our steadfast suppliers. Being a single woman running a hydro store without a big budget wasn’t always easy, so one of my best memories was realizing that the empty cardboard boxes on my shelves (there to make the shop look fuller) were slowly turning into real stock and product. I am proud of my staff for being good Canadians; we strive to keep it as local as possible. That being said, my biggest goal is to keep an open mind and keep on learning. I’ve been fortunate to attend some great seminars in the past 10 years. By meeting people in the industry who are passionate about growing with integrity and learning about quality (in all aspects of the industry, such as service, loyalty, nutrients and gear), my staff and I have focused more and more on educating our customers and helping them produce optimum crops. The exciting thing is that we are always continuing to learn together. We love to teach people about the health benefits of ingesting food grown with seaweed and humic acid, for example. To hear customers come back and report how consuming their own products are drastically improving their health is enough to make it all worthwhile. I feel like we have learned something too, and all of this keeps us humbly striving to serve our North Island customers for at least another 10 good, happy and busy growing years.

Owner Christa Fernau Maximum Yield Canada | November/December 2012

MAX-mART

Maximum Yield Canada | November/December 2012

MAXIMUM YIELD distributors ALBERTA Double AA Garden Supplies Ltd. Bay 9 2820 Centre Avenue Calgary, AB T2A 7P5 403-273-9188 -------------------------------------------------------

Sundogz Garden Supply 1824 Alberni Hwy. Coombs BC V0R 1M0 Art Knapp 2855 Wentworth Road Courtenay, BC V9N 6B7 250-334-3024 Just-N-Tyme Greenhouse and Hydroponics Supply

Garden Centre

Your Plant’s Personal Trainer

IncrediGrow Garden Centre 103-7500 MacLeod Trail SE Calgary, AB T2H 0L9 403-255-0740 ------------------------------------------------------Quick Grow 1-1204 Edmonton Trail Road NE Calgary, AB T2E 3K5 877-426-4769 Smart Grow 2422 - 23 Avenue, NE Calgary, AB T2E 8J4 403-236-9999 Twins Greenhouse 13 - 2235 30th Avenue, NE Calgary, AB T2C 7C7 403-273-2881 Hydro-Lite 12249 Fort Road Edmonton, AB T5B 4H7 780-477-7860 Niloc Wholesale Inc. Box 82008 Yellowbird RPO Edmonton, AB T6J 7E6 780-885-4769

1094 McKenzie Avenue Courteney, BC V9N 3C5 250-703-0476 Pacific NW Garden Supply 1139B Industrial Road 3 Cranbrook, BC V1C 5E3 250-489-4761 Cowichan Hydroponic Supplies 4 - 2955 Jacob Road Duncan, BC V9L 6W4 250-746-0244 Duncan Plants & Ponics 6512 Bell McKinnon Road Duncan, BC V9L 6C1 250-746-5591 Better Than Nature Enderby 1900 George Street Enderby, BC 250-838-5502 Growing Solutions Box 650, 1150 Bowlby Road Errington, BC V0R 1V0 250-248-1101

Fusion 5 Organic Gardens Inc. Box 5821, 120B 1 Street, SW High River, AB T1V 1P3 866-652-2594

Kamloops Sunshine Gardens Greenhouse Superstore 5 - 1744 Kelly Douglas Road Kamloops, BC V2C 5S4 877-372-2270 Room 2 Grow 901 Laval Crescent Kamloops, BC V2C 5P4 250-372-3663

BRITISH COLUMBIA

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Interior Gardener’s Supply 221 - 1 McDermid Road, Box 1779 100 Mile House, BC V0K 2E0 250-395-3399 Solar Greenhouse and Hydroponic Supply 4752 Imperial Street Burnaby, BC V5J 1C2 604-438-7244 Hygro Gardening Supplies Inc. 1791 Tamarac Street Campbell River, BC V9W 5Y7 250-286-0424 Canadian Garden Supply 1730 Highway 3 Castlegar, BC V1N 4W1 250-304-2911 Sun Beam Central 3444 River Road Chemainus, BC V0R 1K4 250-246-1379 Chilliwack Indoor Garden Centre Ltd. 311 - 44500 South Sumas Road Chilliwack, BC V9R 5M3 604-824-2944 -------------------------------------------------------

Retail Stores listed alphabetically by city in each province.

Planting Plus Greenhouse Supplies and Hardware 22394 Dewdney Truck Road Maple Ridge, BC V2X 3J2 604-466-5949 Triple Tree Nursery 20503 Lougheed Highway Maple Ridge, BC V2X 2P9 604-465-9313 Nutty Zone 5 & 6 - 33201 London Avenue Mission, BC V2V 4P9 604-814-2223 Long Lake Nursery Hydroponic Supply 4900 Island Highway, North Nanaimo, BC 250-758-5012 Progressive Growth 41 - 1925 Bowen Road Nanaimo, BC V9S 1H1 800-405-4769 Word of Mouth Hydroponics Inc. 1-1611 Bowen Rd., Nanaimo, BC V9S 1G5 250.591.1180 -----------------------------------------------------------------------------------------------

Tridon Hydroponics 12 - 1708 Bowen Road Nanaimo, BC V9S 1G9 250-755-1900

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Garibaldi Nurseryland & Florist 38917 Progress Way, Squamish Industrial Park Squamish, BC V0N 3G0 604-892-3892

PG2 1798 Nicholson Street Prince George, BC V2N 1V6 250-612-4769; 1-888-817-4769

Coastal Growers Supply 103 - 12824 Anvil Way Surrey, BC V3W 8E7 604-599-1778 -----------------------------------------

Skytek Indoor Solutions 833 4th Avenue Prince George, BC V2L 3H5 800-975-9835 Spruce Capital Feeds 1694 Quinn Street Prince George, BC V2N 1X3 250-564-6010 Omega Garden Inc. 1695 Peligren Place Qualicum Beach, BC V9K 2S3 250-752-1301; 888 976 6342 Garden Effects 200-2288 #5 Road Richmond, BC V6X 2T1 604-214-6620 Pacific Rim Indoor Garden & Lighting 170- 12111 Bridgeport Road Richmond, BC V6V 1J4 604-232-4468 Natural Choice Garden Centre, The 5500 48th Avenue, SE Salmon Arm, BC V1E 1X2 250-832-7151 -------------------------------------------------------

------------------------------------------------------Vancouver Island Garden Supply Ltd. 4770 Wellington Rd Nanaimo, BC V9T 2H3 250-585-8881

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S.A. Ecoline Products Ltd. 5671 Auto Road, SE Salmon Arm, BC V1E 4S1 250-833-4769

Kootenay Grower’s Supply Nelson 721-G Front Street Nelson, BC V1L 4B8 250 353 1887

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Better Than Nature Kelowna 725B Evans Court Kelowna, BC V1X 6G4 250-868-8978

Pacific NW Garden Supply Unit 14- 104 Silica Street Nelson, BC V1L 4M1 250-354-4767

2S7 250-804-2004

Oasis 12 - 1771 Cooper Road Kelowna, BC V1Y 7T1 250-763-4769

Buckerfields 587 Alberni Highway Parksville, BC V9P 1J9 250-248-3243

Pacific NW Garden Supply Unit C1 - 1810 Kyle Court Kelowna, BC V1Z 3Z4 250-769-4791

Sundogz Garden Supply & Hydroponics 30 - 1365 Old Alberni Highway Parksville, BC V9P 2B8 250-954-2046

West Coast Hydroponic Garden Shop 113 - 805 Notre Dame Kamloops, BC V2C 5N8 250-851-2992 -------------------------------------------------------

BC Hydroponics 3 - 20092-93A Avenue Langley, BC V1M 3Y4 604-888-5716 Green Earth Garden Supplies Unit 5, 19300, Langley Bypass Langley, BC V3S 6K2 604-532-7106

Better Than Nature Penticton 101 - 78 Industrial Avenue, West Penticton, BC V2A 6M2 250-770-8978

Excel Air Systems 200 - 20170 Stewart Crescent Maple Ridge, BC V2X 0T4 604-728-0757 Pacific NW Garden Supply 109 - 20110 Lougheed Highway Maple Ridge, BC V2X 2P7

Maximum Yield Canada | November/December 2012

Nico’s Nurseryland 830 - 28th Street, NE Salmon Arm, BC V1E Mylo’s 3837 Squilax Anglemont Hwy Scotch Creek BC V0E 1M0 250-955-0525 Green & Clean Energy Co. Ltd. 2875 Cudlip Road Shawnigan Lake, BC V0R 2W0 250-732-7224 Happy Acres Greens & Backroad Hydroponics Equipment 2058 Cambie-Solsqua Road Sicamous, BC V0E 2V0 250-836-3878 -------------------------------------------------------

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GreenStar Plant Products Inc. 9430 198 Street, Langley, BC V1M 3C8 604-882-7699

Valley Indoor Geenhouse Supplies 103 - 44195 Yale Road West Chilliwack, BC V2R 4H2 877-702-1169

Backwoods Hydroponic & Garden 10590 Carlson Road Prince George, BC V2K 5E5 250-963-9541

Kootenay Bubble Refinery Aurora Lighting 750 3rd Avenue Prince George, BC V2L 3C5 250-564-9888 -------------------------------------------------------

PO Box 81, Slocan Park, BC V0G 2E0 250-226-7753 -------------------------------------------------------

Fat Eddies Systems Inc. 108 - 18760 96th Avenue Surrey, BC V4N 3P9 604-888-2499 ----------------------------------------Garden King Supplies 7533 135 Street, Unit 109 Surrey, BC V3W OM8 604-598-1912 Pacific NW Garden Supply 15374-103A Avenue Surrey, BC V3R 9V8 604-588-4769; 800-443-4769 Warehouse Garden Supplies & Hydroponic 109 - 8173 128 Street Surrey, BC V3W 4G1 604-543-3177 A+ Gardening Supplies 1450 Venables Street Vancouver, BC V5L 2G5 604-876-4769 BN Garden Supply 4493 Boundary Road Vancouver, BC V5R 2N3 604-431-2977 Double AA Garden Supplies Ltd. 2908 Commercial Drive Vancouver, BC V5N 4C9 604-876-8837 Pacific NW Garden Supply 2137 East Hastings Street Vancouver, BC V5L 1V2 604-254-4765 Vancouver Garden Supply 4894 Fraser Street Vancouver, BC V5V 4H5 604-879-8167 Advanced Garden Supplies 7979 Aspen Road Vernon, BC V1B 3M9 250-545-9545 AJs Pets & Things 3219 - 31st Avenue Vernon, BC V1T 2H2 250-549-3222 Better Than Nature Vernon 3506 25th Avenue Vernon, BC V1T 1P4 250-260-4466 Northern Lights Greenspace 3 - 2706 45th Avenue Vernon, BC V1T 3N4 250-558-4757

Indoor Jungle 2624 Quadra Street Victoria, BC V8T 4E4 250-388-5611

Craft N’ Grow 60 Micmac Road Eel Ground, NB E1V 4B1 506-624-9317

Mr. Fertilizer 9 Burnside Road, West Victoria, BC V9A 1B2 250-381-4644

Ultimate Hydroponics Box 1191, Hampton, NB E5N 8H2 506-639-5948

Progressive Growth 111 - 1790 Island Highway Victoria, BC V9B 1H5 250-391-9519

Scott’s Nursery Ltd. 2192 Route 102 Highway Lincoln, NB E3B 8N1 506-458-9208

Sunwest Garden Supply 2035 Unit B Louie Drive Westbank, BC V4T 1Y2 50-768-1636 Good Guys Gardening Center 250 McKenzie Avenue, South Williams Lake, BC V2G 1C6 250-392-2069 Trees Company Nursery & Garden Supplies G9 C17 RR1, 7030 Powell Road Winlaw, BC V0G 2J0 250-226-7334

MANITOBA All Grow Distributors 410 Madison Street Winnipeg, MB R3J 1J1 204-231-1694 Better Than Nature Winnipeg 2B - 2 Donald Street Winnipeg, MB R3L 0K5 204-453-3032 Gro Pro International Hydroponics 101-904 Porthee Avenue Winnipeg, MB R3G 0P4 204-956-1389 Kleen Gro Hydroponics 218 Osbourne Street South Winnipeg, MB R3L 1Z3 204-475-7096 My Two Sons 2 - 2055 McPhillips Street Winnipeg, MB R2Y 3C6 204-339-3489 Nature’s Nutrition 1819 Portage Avenue Winnipeg, MB R3J 0G4 204-889-2979 Northern Lights Hydroponics 129 Regent Avenue East Winnipeg, MB R2C 0C2 204-415-5106 Ready Set Grow! 375 Henderson Highway Winnipeg, MB R3C 2H2 204-668-GROW

Atlantic Hydroponics & Greenhouses Inc. 42 Brandon Street Moncton, NB E1C 7E8 506-858-0158 Jardins Notik Gardens 798 Gray Road St-Charles, NB E4W 4N9 506-876-9100 21st Century Gardening 20 Bayside Drive St. John, NB E2J 1A2 506-657-9982

NOVA SCOTIA

Den Haan’s Garden World 12688 Highway 1, Brickton Annapolis County, NS B0S 1M0 902-825-4722 Woodland Farm Nursery 3544 Highway 1, Annapolis Royal, NS B0S 1A0 902-532-7617 -------------------------------------------------------

S&L Worx Hydroponics 135 Main Street, Unit 14 Dartmouth, NS B2X 1R6 902-434-GROW (4769) -------------------------------------------------------

Sweetleaf Smoke Shop and Hydroponics 3132 Isleville Street Halifax, NS B3K 3Y2 902-454-6646 ------------------------------------------------------Plant Manager Gardening 12 Industrial Drive, Richmond County Industrial Park Lennox Passage, Cape Breton, NS B0E 1V0 902-345-2112

NEW BRUNSWICK Canadian Green Products 811 Central St. Centerville, NB E7K 2B9 506-276-3555 -----------------------------------------

Greenfield Grow & Brew 69 Wilson Mountain Road Murray Siding, NS B6L 4N7 902-897-6568 ------------------------------------------------

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Canadian Hydrogardens Ltd. 1330 Sandhill Drive Ancaster, ON L9G 4V5 905 648 1801 Homegrown Hydroponics Inc. 521 Dunlop Street West Barrie, ON L4N 9W4 705-721-8715 Homegrown Hydroponics Inc. 5386 Greenlane Road Beamsville, ON L0R 1B3 905-563-6121 BMA Hydroponics 404A Maitland Drive, Unit 2 Belleville, ON K8N 4Z5 613-967-9888 D&M Gardens 2961 Main Street Blezard Valley, ON P0M 1E0 705-897-3727 Home Hydroponics 289 Rutherford Road, South 22 Brampton, ON L6W 3R9 905-874-GROW In-Home Gardens 279 Colborne Street Brantford, ON N3T 2H3 519-754-9090 Homegrown Hydroponics Inc. 79 Woolwich Street South Breslau, ON N0B 1M0 519-648-2374 AKA The Indoor Gardener 3014 Highway 29 Brockville, ON K6V 5T4 613-342-2700 Indoor Harvest 3040 New Street Burlington, ON L7R 1M5 289-337-9169 J & C Hydroponics 343 Elgin Street, Unit A Cambridge, ON M1R 7H9 519-622-9969

Steve’s Hydroponic Headquarters 131 Sackville Drive Lower Sackville, NS B4C 2R3 902-865-7764

Dieppe Hydroponics 988 Champlain St. Door #3 Dieppe, NB E18 1P8 506-384-4769

ONTARIO

Woodin Nickel Hydroponics 3393 Central West, Highway 4 Pictou County, NS BOK 1H0 902-695-7640 -------------------------------------------------------

Pro Grow Indoor Garden Supplies 1710 Bishop St. Unit 2 Cambridge, ON N1T 1T2 519-624-7692

Garden Depot 605 Justus Drive Kingston,ON Canada K7M 4H5 613-384-8882 Brite-Lite Indoor Garden Centre 1659 Victoria Street, North, Unit 6 Kitchener, ON N2B 3E6 888-670-0611

All Grow Hydroponic 391 Marwood Drive, Unit 14 Oshawa, ON 866-606-4723

Best of Hydroponics 360 Richmond Street London, ON N6A 3C3 519-858-1533

Paradise Gardens Hydroponics 2158 Chiefswood Road Oshweken, ON N0A 1M0 519-445-2275

Ontario Growers Supply 1540 Fanshawe Park Road West London, ON N6H 5L8 519-641-3992 Vantage Hydroponics 1 Adelaide Street North London, ON N6B 3P8 519-451-4769 Markham Hydroponics 95 Royal Crest Court 18 Markham, ON L3R 9X5 905-305-0698 Nature’s Garden Supplies 24-340 Don Park Road Markham, ON L3R 1C5 905-470-7887 All Seasons 1000 Dundas Street East Mississauga, ON L4Y 2B8 905-848-2619 Green Thumb Hydroponics 3075 Ridgeway Drive, 25 Mississauga, ON L5L 5M6 Hydro Culture Emporium Inc. 150 Robertson Rd Unit 22 Nepean, ON K2H 9S1 613-715-9472 Harvest Time Hydroponics 5918 Main St., Niagra Falls, ON L2G 5Z8 289 296 7754 -------------------------------------------------------

Second Nature Hydroponics 4 - 2133 Royal Windsor Drive Mississauga, ON L5J 1K5 905-403-4769 -------------------------------------------------------

Agrogreen Canada Inc. 1938 Hwy #20, RR#1 Fonthill, ON L0S 1E6 866-650-1136

Nature’s Elements Box 119 500 Mill Street Neustadt, ON N0G 2M0 519-799-5323

Diatomite Canada 1938 Hwy #20, RR#1 Fonthill, ON L0S 1E6 866-650-1136

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Brite-Lite Indoor Garden Centre 1677 Cyrville Road, Meadowbrooke Plaza Gloucester, ON K1B 3L7 613-842-8999 Happy Hydroponics 68 Princess Street Hamilton, ON L8L 3K9 905-545-8434

Supply For You 3615 Weston Road, Unit 6 North York, ON M9L 1V8 416-741-8062

AKA The Indoor Gardener 207 Exeter Road, Unit D London, ON N6L 1A4 519-652-4224

Hydrogarden 1122 Paul Street Cornwall, ON K6H 6H5 613-360-6996

Northern Lights Green Supply 1938 Highway 20 (at 406), RR 1 Fonthill, ON L0S 1E6 905-892-3743

Brite-Lite Indoor Garden Centre 4373 Steeles Avenue West North York, ON M3N 1V7 416-663-2999

Ontario Hydroponics 103015 Grey Road 18 Owen Sound, ON N4K 5N6 519-372-1144 Envirotex PO Box 21069 Paris, ON N3L 4A5 519-442-1237 Peterborough Hydroponic Center 347 Pido Road, Unit 32 Peterborough, ON K9J 6X7 705-745-6868 Sweet Hydroponic Gardens 776 Bruce Street Renfrew, ON K7V 3Z8 613-433-9600 Bluewater Hydroponics 1173 Michener Road, Unit 12 Sarnia, ON N7S 5G5 519-337-7475 Planetary Pride 372 Queen Street East Sault Ste Marie, ON P6A 1Y7 1-888-215-8970 Indoor Gardens Canada 2952 Thompson Road Smithville, ON L0R 2A0 905-957-6969 Green And Clean 761 Barrydowne Road Sudbury, ON P3A 3T6 800-246-5503 Northern Hydroponics 236 Simpson Street Thunder Bay, ON P7C 3H4 807-623-3666 Greenthumbs Garden Supply 338 Kingston Road Toronto, ON M4L 1T7 647-345-GROW (4769) -------------------------------------------------------

grow it all hydroponics for everyone

Grow It All Hydroponics Inc. 165 Geary Avenue, Unit 3B Toronto, ON M6H 2B8 416-588-9595 -------------------------------------------------------

Yield of Dreams Hydroponics 559 Steven Court 12 Newmarket, ON L3Y 6Z3 877-778-7960 -------------------------------------------------------

Green Kingdom Hemp 1103 Cassells Street North Bay, ON P1B 4B3 705-494-7169 -------------------------------------------------------

Homegrown Hydroponics Inc. 26 Meteor Drive Toronto, ON M9W 1A4 416-242-4769 Hydrotech 2436 Kingston Road Toronto, ON M1N 1V2 416-267-4769 Jungle Hydroponics 2215 Gerrard Street East Toronto, ON M4E 2C8 416-699-0861

Maximum Yield Canada | November/December 2012

MAXIMUM YIELD distributors

Retail Stores listed alphabetically by city in each province.

Toronto Hemp Company 665 Yonge Street Toronto, ON M4Y 1Z9 416-920-1980

Jardinages Gilles Robert Inc. 574 St-Hubert Granby, QC J0H 1Y5 450-375-3441

Hydro Expert 12752 Industriel Montreal, QC H1A 3V2 514-624-3091

Hydroculture Guy Dionne 1990 Cyrill-Duquet Local 150 Québec, QC G1N 4K8 418-681-4643

Grower’s Choice Hydroponics 1621 McEwen Drive 14 Whitby, ON L1N 9A5 905-725-GROW

Méristème Hydroponique 871 Dufferin Granby, QC J2G 9H8 450-991-1514

B&S Electrique Inc. 2240 Pitt Street Montreal, QC H4E 4H1 514-931-3817

Pousse Magique 515 rue Lanaudiere Repentigny, QC J6A 7N1 450-582-6662

Northern Lights Hydroponics 2690 Oulette Ave Windsor, ON N8X 1L7 519-254-4015

Jardinage d’intérieur Huntingdon 72 Dalhousie Huntingdon, PQ J0S 1H0, Canada 450-322-6079

Distribution De la Plante 5498 Hochelaga Suite 910 Montreal, QC H1N 3L7 514-255-1111

Urban GreenHouse Hydroponics & Aguaculture 7635 Tecumseh Road E. Windsor, ON N8T 3H1 519-944-8444 urbangreenhousehydroponics.com -------------------------------------------------------

Hydroponique Plus Inc. 405 - 18 Avenue Lachine, QC H8S 3R1 514-634-3677 Biofloral 675 Montee, St. Francois Laval, QC H7C 2S8 877-38-HYDRO -------------------------------------------------------

Ozone Environmental Technologies 361 Rowntree Dairy Road Unit 4 Woodridge, ON L4L 8H1 905-264-6618

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QUEBEC Un Monde Sans Terre 565 Beausejour Alma, QC G8B 5V3 418-480-3274 Hydro-Tonyque 761 Avenue Gilles Villeneuve Berthierville, QC J0K 1AO 450-836-8088 -------------------------------------------------------

Plant-O-Maxx 3169 Blais, Boisbriand, QC, J7H 1H2 514-968-7799

Brite Lite Hydroponics 940 Bergar, Laval, QC H7L 4Z8 450-669-3803

Fernand Corbeil Produits Horticoles - Horticultural Products 17 boul. Ste-Rose Est Laval, QC H7L 3K3 450-622-2710

Les Grands Jardins Lavel 2900, Boul. Cure-Lavelle Chomedey, Laval, QC H7P 5S8 250-729-2687

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Les Entreprises Fernand Pigeon Inc. 174 Beaudoin Nord Durham-Sud, QC J0H 2C0 819-858-2777 Hydromax Gatineau 3-1695 Atmec (porte 6) Gatineau, QC J8P 7G7 819-663-7470 Naturexpert Inc. 828 Chemin du Sixième Rang Gatineau QC J8R 3A4

Pousse Magique Atwater 3522 Notre-Dame, ouest, Montreal, Qc H4C 1P4 Qué-Pousse - Montreal 2215 Walkley Montreal, QC H4B 2J9 514-489-3803

Gerard Bourbeau & Fils Inc. 8285, 1 re Avenue Charlesbourg, QC G1G 5E6 418-623-5401

Pablo Jardinage Drummondville 2080 Joseph St-Cyr Drummondville, QC J2C 8V6 819-475-2525

Momentum 11289 London Avenue Montreal, QC H1H 4J3 888-327-4595

Espace Culture Boutique 17 boul. Ste-Rose Est Laval, QC H7V 3K3 450-622-2710

Hydromax Laval 295 Boulevard Curé Labelle Laval, QC H7L 2Z9 450-628-8380

Les Serres Binette Inc 2568 Boul. Mercurre Drummondville, QC J2A 1H2 819-478-7195

International Hydroponique 5478 Hochelaga St Montreal, QC H1N 3L7 514-255-2525

514-481-3939

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Hydrosphere 2000 2400 rue Canadian, Suite 104 Drummondville, QC J2C 7W3 819-478-9791

Hydromax St-Henri 3522 Notre-Dame Montréal, QC H4C 1P4 514-481-3939

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Hydro Times 1533 Boulevard Cure Labelle Laval, QC H7V 2W4 450-688-4848

Simplement Vert 8B Georges-Gagne Delson, QC J5B 2E1 514-913-8378 (VERT)

Hydromax Montreal 9300 Lajeunesse Montreal, QC H2M 1S4 514-381-0111

------Qué-Pousse - Laval 940 Bergar Laval, QC H7L 4Z8 450-667-3809 ------------------------------------------------------Point De Vue 880 chemin St-Féréol Les Cèdres, QC J7T 1N3 450-452-2878 / 1-877-510-2991 Hydro Rive-sud 4721 Boulvard de la rive sud Levis, QC G6W 1H5 418-835-0082

Summum Bio Teck 2100 Ontario Est Montreal, QC H2K 1V5 866-460-2226 Univert 4 Saisons 2100 Ontario Est Montréal, QC H2K 1V5 514-527-2226 Vinexpert De L’Est 6384 Beaubien est Montreal, QC H1M 3G8 514-354-8020 XXXtractor Inc. 1228 St. Marc Montreal, QC H3H 2E5 514-931-4944 www.xxxtractor.com Qué-Pousse - Mont. Tremblant 462 Montée Kavanagh Mont-Tremblant, QC J8E 2P2 819-429-6145 MegaWatt Hydroculture 636 Route 364 Morin Heights, QC J0R 1H0 450-226-2515 Fleuriste Savard Inc. 1833 boul. Louis-Frechette Nicolet, QC J3T 1M4 819-293-5933 Qué-Pousse - Point-Claire 1860D Sources Blvd Pointe-Claire, QC H9R 5B1 514-426-5057

Fred Lamontagne Inc. 356 Chemin du Sommet Est, Rimouski, QC G5L 7B5 418-723-5746 Qué-Pousse - Sherbrooke 4394 Bourque Rt. 112 Rock Forest, QC J1N 1S3 819-563-0353 Hydro Plus 149 avenue Principale A Rouyn Noranda, QC J9X 4E3 819-762-4367 Rap Hydroponique 5700, rue Martineau Local 7 Saint-Hyacinthe, QC J2S 8B1 450-768-5188 Culture Uni Vert 36 rue de Martigny E Saint-Jérôme, QC J7Z 1V4 www.cultureunivert.com Comptoir Richelieu Inc. 350, du Collège Sorel-Tracy, QC J3P 6T7 800-363-9466 Ferme Florale Inc. (Botanix) 2190 Blvd. Laurier (route 116) St. Bruno de Montarville, QC J3V 4P6 450-653-6383 Hydrobec 2145 Lavoisier Suite 4 Ste-Foy, QC G1N 4B2 418-687-1119 Chanvre du Nord Inc. 38 DeMartigny est St-Jérome, QC J7Z 1V4 866-565-5305 Hydro Sciences 4800 de la Cote-Vertu Blvd. Saint-Laurent, QC H4S 1J9 514-331-9090 Pablo Jardinage Shawinigan 5023 Boulevard Royal Shawinigan QC J9N 6T8 819-731-9766 Sherbrooke Hydroponique 3545 King Est, Sherbrooke, QC J1G 5J4 819-829-9299 Plant-T-Plantes 3439 boulevard Fiset Sorel-Tracy, QC J3P 5J3 450-780-0008 Qué-Pousse - St-Constant 6264 Route 132 Ste-Catherine, QC J0L 1E0 450-635-4881 Benoit Dupuis Extincteurs Inc. 2503 Victoria Street Ste-Julienne, QC J0K 2T0 450-831-4240

Boutique Grunge 364 rue Sherbrooke Magog, QC J1X 2S1 819-847-4141

Boutique Echologik 829, cote d’Abraham Quebec, QC G1R 1A4 418-648-8288

Hydromax Mont-Laurier 388 Rue Hebert Mont-Laurier, QC J9L 2X2 888-609-4476

Boutique Echologik 790 St - Jean Quebec, QC G1R 1P9 418-648-2828

Hydroponique 2000 84 Boul. Curé Labelle Ste-Therese, QC J7E 2X5 450-971-0726

Hydroculture Guy Dionne 8473 - 19th Avenue Montreal, QC H1Z 4J2 514-722-9496

échologik 798 St Jean Québec, QC G1R 1P9 418-648-2828; 418-648-8288

Pépinière Eco-Verdure 965 Boul. Sauvé St-Eustache, QC J7R 4K3 450-472-6474

Maximum Yield Canada | November/December 2012

Amazonia Hydroponique 394 Boulvard Arthur-sauve St. Eustache, QC J7R 2J5 450-623-2790 -------------------------------------------------------

P.P.M. Hydroponique 504 Rue du Parc St. Eustache, QC J7R 5B2 450-491-2444 ------------------------------------------------------Hydrotek 12300 Rue de l’avenir St. Janvier, QC J7J 2K4 St-Jean Hydroponique 747 rue St-Jacques St-Jean-Sur-Richelieu, QC J3B 2M9 450-346-9633 Hydromax Terrebonne 1674 Chemin Gascon Terrebonne, QC J6X 4H9 450-492-7447 Hydromax Trois-Rivières 6157 rue Corbeil Trois-Rivières Ouest, QC G8Z 4P8 819-372-0500 Pablo Jardinage Intérieur 2 Des Ormeaux Suite 500 Trois-Rivières, QC G8W 1S6 819-693-6000 Rap Hydroponique 326 Rue Vachon Trois-Rivières QC G8T 8Y2 819-376-5959 Hydromax Val-David 895 route 117 nord Val-David, QC J0T 2N0 888-320-0129 Val d’Or Hydroculture 1261 3e Avenue Val d’Or, QC J9P 1V4 Horticulture Piégo 228 Pierre Bertrand Sud Vanier, QC G1M 2C4 418-527-2006 Qué-Pousse - Vaudreuil-Dorion 3666-D, boul. Cité des Jeunes Vaudreuil-Dorion, QC J7V 8P2 450-424-0306 Centre Jardin Denis Brodeur 15 Nord C.P. 658 Waterloo, QC J0E 2N0 Sonador Horticulture Inc. 819-479-2941

SASKATCHEWAN Busy Bee Upholstery Box 811, 134 5th Avenue East Gravelbourg, SK S0H 1X0 306-648-3659 B&B Hydroponics and Indoor Gardening 1404 Cornwall Street Regina, SK S4R 2H7 306-522-4769 Waterboy Supply 401 Dewdney Avenue East Regina, SK S4N 4G3 306-757-6242

YUKON, NUNAVUT and NORTHWEST TERRITORIES Porter Creek Indoor Garden Centre 1307 Centennial Street Whitehorse, YT Y1A 3Z1 867-667-2123

wIN BIG! GROw BIG!

MAXIMUM YIELD’S

4 Chances to wIN

every 2nd month for the entire year! Enter now at maximumyield.com/winbig

1 wIN

2 wIN

Xtreme Prize Pack

Nutrifield Prize Pack

The Xtreme prize pack includes 1 qt. (1 L) each of: xtreme Veg, xtreme Juice and Xtreme Boost. Xtreme Veg is an all-in-one root and grow stimulator made from organic matter and seaweed kelp. Xtreme Juice increases efficiency of mineral fertilizers. Xtreme Boost promotes enzyme production, improves resistant to disease and encourages fruit swelling. Visit xtremenutrients.com

The Nutrifield prize pack includes: Lucius Maximus digital ballast, NF Coco, NF zyme and EP FM2 fans. The Lucius Maximus durable, energy-saving digital ballast works on HPS and MH lamps. NF Coco’s improved formula features amino acids, phyto nutrients, vitamins enzymes and more. NF Zyme’s unique formula will optimize root growth. EP FM2 centrifugal fans are built for highouput conditions. Visit nutrifield.us

3 wIN

4 wIN

ExHale Homegrown CO2 From Urban Agricultural

Current Culture H2O Prize Pack

ExHale® Homegrown Co2 is a revolution in indoor CO2 production. ExHale cultivates CO2 24 hours a day with no need to refill bottles or use expensive CO2 production units. ExHale is designed for a 4- by 4-ft. area and is guaranteed to produce CO2 for at least six months. Maintenance free! No heat! No electricity! Just CO2. Visit exhaleco2bags.com

Current Culture H2O is giving away a UC Solo™ single module water culture system and Cultured Solutions™ premium plant nutrient sample pack. Includes a 13 gal. growth module, Heavy Harvest lid with convenient porthole, custom-molded heavy-duty net pot, drain valve kit, Eco Plus dual air pump, air hose, two medium round air stones and Growstones™. Visit cch2o.com

Draw closes on December 15, 2012. For complete contest rules, go to maximumyield.com/winbig Prizes might not be exactly as shown.

COMING UP NEXT ISSUE

DO YOU KNOW?

Moving air within the plant canopy has a cooling effect, keeps the plant foliage dry and the carbon dioxide concentration within the canopy air at the ambient level, and stimulates the evaporation of transpiring water from leaf surfaces.

Very high light intensities will break down chlorophyll, imparting a white, bleached appearance to the leaves and resulting in a decreased ability to carry out photosynthesis.

Clean and Green: Hydroponic Hygiene The warm and moist environment that is ideal for plants in an indoor garden is also ideal for a host of nasty life forms that we don’t want in our gardens. In keeping the grow space “clean and green,” proper hygiene and regular maintenance can go a long way.

Garden Pharmacy: Grow Your Own Vitamin C Vitamin C is one of the most important nutrients in the human diet, and it’s especially needed during a Canadian winter. Grow your own vitamin-C-rich crops indoors all winter long.

Are You Ready for 4G Acceleration? What is the history of the LED movement and where is it heading? What does all this mean for the indoor gardening industry? Learn the answers to these questions in this article about LEDs, the fourth generation!

Plus: Hydroponic news, tips and trivia; hot new products; exclusive giveaways and more!

www.maximumyield.com Maximum Yield Canada (January/February) will be available in January for free at select indoor gardening retail stores across Canada, and on maximumyield.com Subscriptions are available at maximumyield.com/subscriptions and maximumyield.com/digital-subscription

If the CO2 in an enclosed environment gets used up by the plants and is not replenished, the plants’ ability to photosynthesize will be compromised—ventilation systems replace stale, CO2-depleted air with fresh air containing new CO2 for plants to process.

Ventilation is an essential component of evaporative cooling as the evaporation of water causes humidity levels to rise.

The air around us contains roughly 200 to 300 ppm (or, 0.02 to 0.03%) CO2. Plants do well in this range, but we have learned that you can supercharge your garden by enriching the atmosphere in your grow room to 1,200 to 1,500 ppm (or, 0.12 to 0.15%).

The base ingredients of a soil are the substances that make up the bulk of the soil itself. They are most responsible for the soil’s physical properties and texture, and some of them also make up the backbone of the nutrient content.

Many commonly used rooting media are derived from naturally occurring substances; therefore, they contain some, or many, of the essential plant nutrient elements.

Soils with added perlite will dry out quickly between each watering, which gives a grower more control over a feeding regiment.

Maximum Yield Canada | November/December 2012

Unlike other soilless substrates that arrive pre-sterilized, chemically inert with a low CEC and with a minimal effect on the composition of the nutrient, coco contains naturally occurring potassium.