THE ULTIMATE ROOT ZONE ››

Ultimate Root Zone! By Baron Wasteland

The first few days of a plant’s life are often overlooked but are among the most crucial to success. Getting the best root system possible at this stage will not only increase final yield dramatically, but also give a healthier plant in general. This in turn allows you to make the most of your time and space with a faster growing plant able to support more flowers. Here

we outline the ultimate method to get an outrageous root system in your plant from day 1.

We will cover how to easily make a homemade hybrid dripper system with integrated air pruning, which makes young plants produce an abundance of fresh healthy roots. Also we’re going to explore in depth the optimum nutrient feeding regime, so your young plants will get further, faster with their first tender steps. Kind of like a kindergarten for your little green babies.

Shopping List

To get the Ultimate Root Zone using this system you will need to aquire the fol-

lowing (you may already have a lot of this kicking around): standard height) peat that expand in water) as large as the space needed for your rockwool, at least 3 inches deep and watertight. (optional) the large plant tray (cheap greenhouse shelving works well) systems dripper manifold to each plant more than you need)

A gentle weaning.

There are plenty of articles about cloning and planting seed, so right now let’s skip that and assume you are already gleefully about to take some cuttings or plant some seeds in preparation for the next crop.

All healthy root zones are born from a high quality soil or hydroponic substrate. Every seasoned grower has their own favourite first planting medium, whether soil, rockwool, perlite, clay pellets or coco; pretty much any of these work just fine. But we don’t want to settle on “fine”, we want the ultimate!

Peat Pellets with no added NPK nutrient for the first couple of days give the best start to many of our favourite plants. Peat pellets are full of natural gentle nutrients, so by using them at this early stage we give an organic weaning when the plant is at it’s most fragile (this will ease the transition If you switch to mineral feed later in the grow). It also has a little more moisture retention than rockwool, which we will use to our advantage in the next few stages.

Soak the peat pellets in some warm water, pH adjusted to 5.6. At this stage you should not add any NPK fertiliser, only add a little root booster (Rhizotonic or similar). Adding Trichoderma fungus at this stage too (Biopak/Aktrivator or similar) adds an amazing secondary root system that grows with your plant’s own roots, allowing more efficient nutrient uptake and also guarding against pythium and other substrate horrors! Using a good enzyme product throughout the cycle helps the rhizosphere stay healthy, process dead tissue and convert it quickly into nutrients.

Fast flushing of rockwool.

After the first roots peek out from within your peat pellet it’s time to transplant into your rockwool cubes. Before you do this you need to remove the residual lime present in the rockwool from manufacturing. This must be flushed out fully to prevent the substrate’s internal pH being raised way too high. stable once flushed properly. The reason pH can rise in the substrate is actually due to the plants active growth and is a good sign (as long as you correct it back down before it gets too high!). More on this later.

Common practice is to soak rockwool cubes overnight, but this is overly time consuming. Much faster is a three stage flush:

them around, and generally being a little rough with them to break the cubes up a bit, giving a fast flush of the lime.

Leave them to soak for 5 minutes then squeeze the cubes out and discard all this liquid. treat them nicer this time, just a few light squeezes under the water then let them soak for half an hour. Discard this water. water adjusted to pH 5.5 in which they’re left to soak for half an hour. Discard this solution and squeeze most of the liquid out of your cubes. Now your rockwool is ready to receive nutrients & plants!

Because our babies have already got roots peeking out from the peat pellet, we can now prepare a very light solution of NPK veg nutrients, root booster, seaweed extract and trichoderma for the

rockwool – at this stage we only take the mix to 1.1 EC from seed (1.2 EC if from cuttings) and bring the solution to pH 5.5. Soak your rockwool cubes in this solution for an hour. Carefully drop your plants into the rockwool, gently close up any gaps between the peat pellet and rockwool, then sit back and feel pleased with yourself.

Make your rootin’ tootin’ root boostin’ hydroponic kindergarten!

a week to ten days, but it gives them the best start possible before you install them in their final home. Nutrient solution is pumped through the rockwool, dripping out from underneath into the tray to create a recirculating active system.

The magic comes with the screen – as the roots grow through, they hit air and the tips die off triggering an explosion of new root growth from within. We time the feed schedule and adjust the nutrient composition to encourage the most extreme roots possible before we transplant to their final site.

Sterilise your trays, pump and screen. Diluted Hydrogen Peroxide or isopropyl alcohol works well and doesn’t leave any residue that’s unfriendly to plants. Put your small tray down on the bench and attach your pump to the base, towards the back end of the tray and away from the centre. Lay your screen over the tray. Next fit your inline filter to your pump, then your dripper manifold and tubing. The pump filter and manifold should be sticking up through the hard screen.

It is useful to use the smaller plant tray at this early stage, as you won’t need to make up such large quantities of feed just to get the depth high enough for the pump to work efficiently. Using less nutrients is also more economical for you and better for the environment too with less waste solution. As the plants grow too large for the small tray you can simply lift the screen, pump, plants and dripper in one convenient movement and swap the bottom tray to a larger one.

If your screen is unsupported anywhere you can place a couple of metal rods laying across the top of the tray under the screen, supporting the weight of your wet rockwool. Alternative methods are to fold the screen edges carefully up to give some rigidity or better yet just get a larger screen and cut it to fit, leaving an inch or so of overlap all around the large tray.

Think about your plant spacing and cut your dripper delivery tubing to reach each plant easily, but avoid leaving masses of

excess to get in the way when they are tiny and bunched closer together. Depending on what you are growing, you may need to allow for up to a 12 inch circumference of space per plant by the time you are ready to transplant again in about 10 days. Now it’s time to install the plants. Place them directly onto the screen and push a dripper stake into each rockwool cube. It’s easiest to work from the closest to the pump outwards. If you’re working with seedlings they are still absolutely tiny at this stage so you can bunch up the cubes

to make the best use of your light coverage. Space them out as they grow, so none of the plants ever touch each other at this early stage. If young plants feel restricted they won’t develop such good lateral branching.

Optimising your feed schedule strength and timing

Make a full spectrum vegetative nutrient solution with NPK+micro nutrients+root booster. We still keep the solution light at this stage, so we mix until we measure 1.1 EC for seedlings, 1.2 EC for cuttings. Tip this into your tray, which conveniently acts as your tank too. Test the pump & dripper are working as expected, with even flow from all the dripper stakes.

The nutrient solution should fill each cube and drip through back into the reservoir from multiple points on the base of the cube. Ensure that the dripper tubing isn’t pulling the stake back into the plastic wrapper on the rockwool, or you risk some nutrient running down the outside and missing the young plant altogether.

If growing from seed, increase nutrient strength to an EC of 1.2 after they’ve been in the rockwool for 3 days, and keep it there until transplanting next week. Often when people use dripper systems, they use a very fast timer to only replace a small amount of nutrient per feed. This approach will lead to inaccurate pH measurements, as when the plant grows, the pH inside the cube raises too. By only replacing tiny amounts of nutrient at a time you are simply compounding that problem! But by running the pump for 15 minutes at a time it allows the fresh nutrient to permeate through every part of the cube, pushing out the old solution. You should see it dripping out from different points across the base.

When plants are first installed in the rockwool the roots will be minuscule inside the peat pellet, so we only run the pump once a day for 15 minutes in the morning, as we want the cube to dry out slightly over the day to stimulate root growth. As soon as you see the first roots come out of the base of the rockwool cube, run the pump twice a day in the morning and early afternoon. When these first protruding roots have withered and died back and you see the following reactive cluster leaping out of the base you know the system has worked. Keep the feed strength at 1.2 EC, pH at 5.5 and feed this 4 times a day, 15 minutes each time. Have the last feed about 2 hours before lights out. As the plants grow you will see the most outrageous root system emerge. Allow the roots at the bottom of the cube to die repeatedly and hold your nerve… Keep them on the screen for about another week, until the cube is literally carpeted in fresh vibrant roots. Increase the number of feeds a day gradually over the week, judging how long it takes for the cubes to feel lighter. By the time you move the plants on you will need to feed about 8 times per day (in an 18 hour day), as there are literally too many roots to fit in the cube and it will be thirsty and dry out fast; this is why the extra water-retentive properties of the peat pellet works in our favour now, by holding a little extra moisture for longer right at the core.

Peek down the side of the plastic wrapper and you should see a mass of pure healthy white roots, looking like the cube in the picture. The plants are now ready to transplant into their final home. Enjoy your massive yield!

baronwasteland@gmx.co.uk

AERATING HYDRO WATER

Why are aquarium bubblers or aeration stones used in hydroponic reservoirs? Is it to enrich the water with carbon dioxide (CO2)? Should I use an aquarium heater to raise the water temperature? At what temperature should I keep the water?

MARLON S.

Aquarium bubblers are used to enrich the water with oxygen, not CO2. Plant leaves capture CO2 and use it as an ingredient for photosynthesis. The plants use light energy to cleave water into its two elements, hydrogen (H) and oxygen (O). Then they combine the H with CO2 to make sugar. Plants use the sugar as a source of energy to carry on life processes and also as a building block for the creation of new tissue.

Roots do not contain chlorophyll, the pigment that captures and converts light energy, so they have no need for CO2. They do require oxygen, which they use to burn the sugar to create energy.

Air bubblers enrich the water with oxygen, which comprises about 21 percent of the atmosphere. They do it in two ways: First, the water absorbs oxygen directly from the bubbles floating up to the surface. Second, by circulating the water more water comes in contact with air at the surface. There, the water exchanges CO2 released by the roots for oxygen that the roots absorb.

As water warms, its ability to hold free oxygen lessens, so roots are more likely to encounter anaerobic conditions in warm water. Water holds sufficient free oxygen at 20ºC–22ºC. At higher temperatures, when it holds less oxygen, oxygenating the water becomes much more important.

LIGHT INTENSITY

I use 16 1000-watt HPS lamps with Adjust-A-Wings reflectors. I like them because their parabolic shape spreads the light more evenly over the entire garden, which eliminates shadows and ultimately increases overall yield. Unfortunately, it’s difficult to use these types of reflectors and get higher than 54,000 lumens per square meter at the canopy without heat issues, especially when multiple strains are being grown and the canopy becomes less uniform.

My question: If my priority is to grow the highest-quality product instead of maximizing yield, should I use focused reflectors instead?

JOE

Ed Rosenthal is recognized worldwide as a leading authority on marijuana. In his 30-plus years as America’s “guru of ganja” he has written or edited more than a dozen books about marijuana cultivation and social policy that cumulatively have sold over one million. His first book, Marijuana Grower’s Guide, is the only title on marijuana cultivation to be reviewed by The New York Times Book Review. After almost two decades, his Ask Ed advice column continues to answer questions on all matters of marijuana from readers around the world.

Most cannabis plants grow very well and produce high yields under 54,000 lumens per square meter. The plants that are most likely to improve with increased light are sativas and sativa–indica hybrids.

The problem with the parabolic lights you are using in terms of increasing light intensity is that the reflectors have a big footprint and cannot be placed close to each other.

One solution to your problem of trying to increase light intensity is to use HO or VHO fluorescent lamps in addition to the lamps that are already installed. These 120cm tubes vary between about 50–100 watts. High-watt compact fluorescent lamps are also available. All these tubes are fairly efficient and can be mounted between or under the HPS lights.

WHEN TO SPRAY

After spraying the plants with a pesticide or fungicide is it best to keep their lights off for a bit afterwards?

ASHLEY

Yes. When spraying a pesticide or fungicide it is usually best to keep the lights off for a while so the spray will have more time as a liquid and have a greater chance to reach its targets.

CO2 SHUTOFF

When should I shut off CO2 during flowering? Should I run it until the end of flowering or should I stop it earlier?

MR. FERTILIZER

As long as plants are photosynthesizing, which they continue throughout the flowering period, CO2 enrichment increases the rate of photosynthesis so it speeds growth and maturity. Keep it on throughout the flowering process. Cannabis does not gather CO2 during the dark period, so there is no need to enrich the air during the dark period.

OVER-FERTILIZATION

After watering it yesterday the leaves curled. Still super green leaves and the plant is vibrant and bushy. Did I overwater?

JULIA

Overwatering did not cause the problem your plants have. When plants are in a constant state of being “overwatered” and are suffering from anaerobic conditions (not enough oxygen) at the root level, first the leaves droop and lose their luster and then the stem and roots may be attacked by pathogens.

The reason the leaves started curling is the result of too much nutrient in the soil or water. The plant is having trouble drawing up water because the nutrient levels in the water are so high.

The solution to the problem is to flush the container with pH’d water to remove some of the nutrients. When this happens the concentration of salts in the plant will be higher than in the soil and the plants will once again be able to draw up water and resume healthy growth.

This plant is suffering from nitrogen toxicity in late flowering. Tapering off the use of nitrogen toward flowering

CONSTANT GREEN LIGHT

I left a green light on at night in the final week of flowering. What effect will this have on the plants?

TIMOTHY C.

Marijuana is a short-day plant, which means that its flowering cycle is based on the number of hours of uninterrupted darkness it receives. It measures light and darkness based on red and far-red light and, to a much lesser effect, based on blue light.

Short-day plants are not affected by green light in regard to the flowering cycle, so it is safe to leave a green light on during the flowering period. Both LED and fluorescent green lights do not emit red light so they are excellent sources of green light.

WHITEFLIES

My plants are in week 5 of flowering. How can I safely remove whiteflies at this point of flowering? The plants have many nice size buds and I don’t want to harm them or the end user.

GOLENDER

Whiteflies are true bugs and are close relatives of aphids. They use a proboscis, a mouth modified into a straw, to puncture the plant and suck its juices. They are very prolific and can quickly drain a plant of its energy.

There are several ways you can get rid of them. Pyrethrum, a natural organic pesticide, or an herbal pesticide can be used to knock the population down and, with several sprays about five days apart, can eliminate the population.

Encarsia formosa is a solitary parasitic wasp that lays eggs in whitefly pupae. They cannot sting you and are so small that you may never see them again once you release them. Adults emerge from the dead host ready to reproduce. They are very effective in warm climates, greenhouses, and indoor gardens. You will see a gradual reduction of whiteflies and they will be virtually eliminated.

My ideal program is to use organic pesticides twice, about four days apart, to knock the population down. Then wait a few days and introduce the wasps.

Several plants in one container cover the area more completely than a single plant whether topped or untopped.

TIGHT PLANTING

In Marijuana Grower’s Handbook you say that three plants in one container had a greatest yield over the topped plants. What size container would you recommend?

FARBERGE

Increasing the number of plants in a container to increase yield works on both small containers (30cm in diameter) as well as large ones such as outdoor raised beds. With more plants the canopy becomes more fully colonized so the space is fully used.

This technique is more effective when growing sativas and sativa hybrids than with indicas, which fill the space more completely.

BANANAS ON BUDS

Is it normal for male flowers to appear on the buds as the plant is ripening? Are these the little yellow flowers? Is it best to pull them when they appear in ripening to avoid seed production?

AMBER

Male flowers sometimes grow on buds just as they are ripening. It is safe to leave them on if there are no young buds around because the buds they are on are about to be picked and will not continue growing.

The problem with these flowers, often called bananas, is that they are considered undesirable commercially and lower the price of buds substantially. For this reason processors remove them as they manicure.

These male flowers contain all female genetics because they grew on female plants that have no male DNA. Seeds produced using this pollen to pollinate female flowers will produce only female seeds.

HOT ROOTS

I am having trouble keeping canopy and hydroponic roots at acceptable temps. The roots are too warm, way above 21ºC. What should I do?

DAN AND TINA H.

Use a water chiller designed for aquariums. It will keep the water cool without contaminating it with unwanted metals such as copper. Units not made specifically for plants or aquariums should not be used because the plants risk contamination.

HIGH TEMPERATURES

Do high temperatures [over 32ºC] slow the growth of plants?

STEFAN

Yes. When the temperature gets into the high 30s (ºC) plants stop photosynthesizing, and instead go into a stress mode. During this period the stomata (plant pores) transpire water to cool the plant (the equivalent of our perspiring to cool off).

As the temperature increases to 30ºC photosynthesis and metabolism speeds up, just as it does in cold-blooded animals. However, when the temperature rises above that level, cannabis quickly changes from fast processing to preservation mode. During periods of heat stress, plants transpire water to keep cool.

This chart shows the drop in rate of photosynthesis as temperatures get too high

BENEFICIAL NEMATODES

What species of nematodes should I use to get rid of root aphids?

HAZE MAN

Beneficial nematodes are microscopic organisms that look like worms. They attack soil-dwelling insects by entering their bodies and eating them from the inside and laying eggs inside the host. The host dies and the newborns emerge, all looking for a meal. As long as there are insect hosts they keep reproducing.

The best species to use is Steinernema feltiae. They hang out in the first few inches of soil, where many root aphids dwell. Another species, Heterorhabditis bacteriophora, is also helpful. They live deeper in the soil. Once they are introduced to the medium the population will grow as long as there are insects to feed on.

Powdery mildew spreading throughout the plant

WHITE WEBBING IN BUDS

I recently harvested. While breaking up my dried cured nugs I noticed very fine weblike strands coming from the bud. Even when I pinch a tiny piece and pull it apart I can see a bunch of these little hairs. Is it a mold?

ALTER TEE

The webbing or strands you see are signs of powdery mildew or a close relative. The buds are thoroughly infected.

Although it is not associated with human disease I feel uncomfortable about smoking it. The buds can be used for water concentrates or BHO because the infection will be washed away.

To control powdery mildew you must be ever vigilant and check your plants. There are several methods of preventing powdery mildew infections. They are detailed in Marijuana Grower’s Handbook, Marijuana Pest and Disease Control, Protect Your Garden, and Marijuana Garden Saver.

Close-up of filamentary strands of powdery mildew hyphae