VOL. 16/NO. 2
Summer 2015
Saving Water and Money:
Irrigation for Increased Nursery Profitability and Efficiency UT Gardens’ 2014 Best & Beautiful Edibles, Shrubs, Trees and Roses
Pick Your Pot... Are Container Alternatives Right for Your Nursery Operation?
VOL. 16/NO. 2 •
Cover Story Saving Water and Money: Irrigating for Increased Profitability and Efficiency
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In the landscape UT Gardens’ 2014 Best & Beautiful Edibles, Shrubs, Trees and Roses
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Summer 2015
In the nursery Pick Your Pot... Are Container Alternatives Right for Your Operation?
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more features Green Gatherings Tennessee Green Industry Expo, September 17–18, 2015, Nashville, TN..........................................................................7
DEPARTMENTS From the President, Jeff Harrell.....................................................................................6 Recent Event....................................................................................................................8 TNLA New Members.......................................................................................................9 Index of Advertisers.......................................................................................................21 Calendar of Events.........................................................................................................22
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The Tennessee Nursery and Landscape Association serves its members in the industry through education, promotion and representation. The statements and opinions expressed herein are those of the individual authors and do not necessarily represent the views of the association, its staff, or its board of directors, Tennessee GreenTimes, or its editors. Likewise, the appearance of advertisers, or their identification as Tennessee Nursery and Landscape Association members, does not constitute an endorsement of the products or services featured in this, past or subsequent issues of this quarterly publication. Copyright ©2015 by the Tennessee Nursery and Landscape Association. Tennessee GreenTimes is published quarterly. Subscriptions are complimentary to members of the Tennessee Nursery and Landscape Association Third-class postage is paid at Nashville, TN. Printed in the U.S.A. Reprints and Submissions: Tennessee Green Times allows reprinting of material. Permission requests should be directed to the Tennessee Nursery and Landscape Association. We are not responsible for unsolicited freelance manuscripts and photographs. Contact the managing editor for contribution information. Advertising: For display and classified advertising rates and insertions, please contact Leading Edge Communications, LLC, 206 Bridge Street, Franklin, TN 37064, (615) 790-3718, Fax (615) 794-4524.
From the President Jeff Harrell
Good News for Our Industry
W
inter 2015 was filled with sleet, snow and record low temperatures, which made for a messy digging season. However, summer looks promising. According to The Tennessean (Nashville’s daily newspaper), the U.S. economy saw its best year in 2014 since the 2008 recession. As we move forward in an upward economy, the housing market seems poised to make a real comeback, and this is good news for our industry. We’re all hopeful that fall 2015 will be prosperous for the nursery and landscape world. Now is the perfect time to book your booth in the 2015 Tennessee Green Industry Expo. TNGIE is always looking for plants, new equipment, products and services, and spaces are already being reserved. The show will be held September 17–18, at the new Music City Center in downtown Nashville (for more information visit tngie. com). I encourage you to get involved and take advantage of the opportunities that we offer. The Expo is a great place to showcase your products and meet with new clients. I look forward to continuing to work with the TNLA board of directors. We will do everything in our power to make this organization a useful resource to you. We challenge you to inspire others in the industry to join TNLA and to connect with current members to build lasting relationships. We encourage feedback — your input and ideas will help make this association better, stronger and more relevant. The TNLA board and I would like to extend our appreciation to all members for your involvement and support. I want to leave you with a fitting Chinese proverb: “The best time to plant a tree was 20 years ago. The second best time is now.” I hope to see everyone at the TNGIE Expo in the fall!
Jeff Harrell 2015 TNLA President
Gold Membership Sponsors
Silver Membership Sponsors
Barky Beaver Mulch & Soil Mix, Inc. Hale & Hines Nursery Co. Nashville Landscape Systems, Inc. Putnals Premium Pine Straw Randall Walker Farms Samara Farms Swafford Nursery, Inc. Tennessee 811
Allen Landscape Management Common Grounds Evergreen of Johnson City Freedom Tree Farms Warren County Nursery
tennessee greentimes Summer 2015
Published by Leading Edge Communications, LLC 206 Bridge Street Franklin, Tennessee 37064 (615) 790-3718 Fax (615) 794-4524 Email: info@leadingedge communications.com Editors Dr. Bill Klingeman Dr. Amy Fulcher Associate Editors Dr. Donna Fare Dr. Nick Gawel Dr. Frank Hale Mr. Gray Haun Dr. John Sorochan TNLA Officers President Jeff Harrell Tennessee Valley Nursery 1st Vice President Kim Holden Holden Nursery 2nd Vice President Josh Woodlee David’s Nursery
TNLA Would like to THANK the following companies for being MEMBERSHIP SPONSORS
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The Tennessee Greentimes is the official publication of The Tennessee Nursery & Landscape Association, Inc. 115 Lyon Street McMinnville, Tennessee 37110 (931) 473-3951 Fax (931) 473-5883 www.tnla.com Email: mail@tnla.com
3rd Vice President Justin Stelter Justin Stelter Landscape Gardening Secretary-Treasurer James Hines Hale & Hines Nursery, Inc. Associate Director Bob Elliott Ewing Irrigation Ex-Officio Matt Dawson Samara Farms Executive Director Louree Walker
Recent Event
Highlights from the HRI/TNLA Classic Golf Tournament June 16, 2015 • WillowBrook Golf Course • Manchester, TN Congratulations to Our Lowest-Score Winners!
First-Place Team:
Jim Denning, Monroe Oakes, Jasper Adkins and Mike Denning
Second-Place Team:
Kenny Pryor, Gary Griffin, Milton Whitsett and Bill Arter
Third-Place Team:
Clint Moore, Robert Jones, Jeff Harrell and Jeff McMahan
Thanks to Our Sponsors!
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Bill Holt Chevy-Buick-GMC Black Fox Farms Botanico, Inc. Bouldin’s Gateway Tire BWI, Inc. Cherry Springs Nursery Dayton Bag & Burlap Co. Denning & Cantrell CPAs, PLLC East Jordon Plastics Everris Florikan ESA, LLC Forest Nursery Co. General Equipment Co. Griffin Greenhouse Supplies Hale & Hines Nursery Co. Hans Nelson & Sons Nursery Harrell’s Fertilizer, LLC Haviland Plastic Products Co. Hillis Trucking Huff & Puff Trucking John Holmlund Nursery, LLC Kidd Ford Lee Smith Isuzu Mize Farm & Garden Nursery Supplies, Inc. Osmocote ICL/Specialty Fertilizer Pleasant Cove Nursery, Inc. Riverbend Nurseries, Inc. Security Federal Savings Bank Swafford Nursery, Inc. Tennessee Valley Nursery Tennessee Valley Tractor Walker Nursery Co. C
Welcome,
TNLA New Members! Active Member
Green Pastures Landscape Co. David Shore P.O. Box 41791 Nashville, TN 37204
Associate Members Describeit David Marciniak 814 S. Blue Ridge Avenue Culpeper, VA 22701
Green Earth Solar Cory Anderson 9111 Cross Park Drive, Suite E-120 Knoxville, TN 37923
AFFILIATE Members Anthony Witcher TSU Nursery Research Center 473 Cadillac Lane McMinnville, TN 37110
Cover Story
Saving WATER, Saving
MONEY: Irrigating for Increased Nursery Profitability and Efficiency By Halee Jones, Recent Graduate, Department of Plant Sciences, and Amy Fulcher, Ph.D., Extension Specialist and Assistant Professor for Sustainable Ornamental Plant Production and Landscape Management, The University of Tennessee
In
the first article in this series, “Nursery Irrigation: The Importance of Water Availability and Efficiency,” published in the Spring 2015 issue of Tennessee GreenTimes, we discussed reasons why nursery growers may want to look closely at their water use, including issues that could lead to water scarcity and the economic and production benefits to refining water use. In this article, second in the series of three, we will cover how growers can make small or big changes to their irrigation practices that improve not only plant quality and profitability, but also reduce water consumption. Growers who use water effectively not only help reduce the demand for freshwater resources, but they also cut costs and increase production efficiency in their nursery. While water is critical to plants, both too much and too little can be harmful. Plants that don’t receive
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the needed amount of irrigation grow more slowly, which increases the amount of time it takes to reach a mature or marketable plant size. Conversely, too much water can also slow growth and lead to root rot, increased fungicide use (and related costs) and increased plant death. When the distribution within a zone is not even, growers will use more water to irrigate. For example, when water distribution (measured as distribution uniformity) is not consistent, an overhead irrigation system will often be operated to sufficiently wet the driest areas, meaning that plants in other areas of the zone are over irrigated. Let’s examine some ways that growers can increase the uniformity and efficiency of irrigation.
Identifying inefficiencies The most common form of irrigation in the nursery industry is overhead irriga-
tion. Overhead irrigation is the cheapest and most effective method of irrigating relatively small container sizes. Overhead irrigation systems are useful when covering large areas of land. They also don’t require the messy and more expensive tubing that drip irrigation systems require. However, overhead irrigation is also the most wasteful form of irrigation. Inefficiency can easily occur with overhead irrigation due to poor distribution uniformity (as mentioned above), which can be caused by inappropriate system design or clogged, worn and/or damaged emitters or risers (see Photo 1). In addition, overhead irrigation of container crops is inherently wasteful due to poor application efficiency, specifically poor interception efficiency. Depending on pot spacing, up to 80% of overhead irrigation misses the intended target. By spacing pots closer together, we reduce
the amount of space between containers and usually increase the amount of water intercepted by containers, which increases efficiency (Photo 2). Weather also plays a role in application efficiency. Wind speed and sun intensity increase as the day progresses.
Greater wind and air temperature reduce overhead irrigation application efficiency due to drift and evaporation, and they increase the need for irrigation. This is why natural or constructed windbreaks should be used to minimize wind and improve irrigation application efficiency and uniformity. Wind, evaporation, inappropriate plant spacing, poor system design and clogged emitters will lead to over or under irrigation of part or all of the target crops. The potential consequences of inefficient irrigation include wasted water, increased nutrient and pesticide leaching (removing nutrients and pesticides from the foliage and container substrate), increased water runoff and movement of contaminants in runoff from production surfaces, increased insect, mite and disease problems and water stress, reduced plant growth, increased plant death and increased production duration.
Irrigation and IPM Many nursery growers now use Integrated Pest Management (IPM) strategies to produce their crops. Not only does IPM help control pests, but also it can reduce pesticides in runoff. In fact, a study conducted at Clemson University shows that the implementation of IPM strategies effectively reduces the amount of fungicides transported in runoff water, without compromising container plant health or marketability. Combining IPM along with refined irrigation practices can lead to many benefits, both for the producer and the environment.
How can you tell if plants have similar water needs?
Section Name
Photo 1. Risers that are not 90 degrees can lead to poor irrigation uniformity.
Nutrient and pesticide leaching can create a number of problems. The need to reapply controlled-release fertilizers and preemergent herbicides and other pesticides more frequently or to use higher rates will have a negative impact on nursery profits. Nutrient or pesticidecontaminated leachate can also cause harm to the environment. Luckily, many practices — some of them easy and inexpensive — can be integrated into nursery production to improve irrigation efficiency and avoid the problems associated with inefficient irrigation.
Improving irrigation efficiency
Photo 2. When they are small, plants can be spaced pot-to-pot (like the boxwoods in the foreground) to increase the interception of irrigation water. Carefully space the plants as they grow so that excess spacing doesn’t cause inefficient irrigation.
Cyclic Irrigation
6 am
11 am
3 pm
Standard Timer-Based Irrigation
6 am Figure 1. In cyclic irrigation (top), the volume of applied water needed per day is divided among three smaller irrigation events, as opposed to standard timerbased irrigation (bottom) that typically comes on in the early morning and is left on for a long time. 12
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Some simple practices that improve efficiency include choosing a substrate with adequate or enhanced water-holding capacity, grouping plants into zones based on water requirements, spacing plants within a zone and refining irrigation timing and volume (collectively known as irrigation scheduling), along with irrigation system design and delivery. However, until the distribution uniformity is at an appropriate level, the benefits of these efforts will not be maximized. As mentioned above, distribution uniformity is the measure of an irrigation system’s ability to apply water evenly within a zone, which in turn will affect how much water is being applied. Measuring distribution uniformity will be described in detail in our third article (to be published in the Fall 2015 issue of Tennessee GreenTimes). Along with checking, and if needed, improving your distribution uniformity, consider adopting some of the low-tech and/or high-tech ways to improve irrigation efficiency that are discussed in the following paragraphs. Grouping plants into zones based on water requirements can lead to more efficient water use. See the sidebar (above, right) for information on how to determine water requirements for different species. Decreasing the space between each plant will decrease the amount of water that falls between containers, hits the ground and becomes runoff. However, consider the role that canopy shape and size play on intercepting overhead irrigation and rainfall. The smaller a plant is (for example, early in the production cycle), the less of a
With a bathroom scale, you can use this simple technique! 1. Water plants. 2. Weigh after plants stop dripping. 3. Weigh again 24 hours later. 4. The difference is water used by the plant (and evaporated from the substrate) in one day. 5. Compare different species’ water use to decide how to group plants in irrigation zones. factor the canopy is, and close spacing can be used to increase interception efficiency. The larger a plant becomes, the more canopy size and shape play a role in funneling water down into the container or, conversely, shedding water away from the container. When water is channeled by the canopy toward the container, space plants adequately so that they are sure not to “rob” one another of water. Also, adjust irrigation time accordingly, as more water than the application rate would indicate is going into the container. Knowing your application rate is an important step in refining nursery irrigation efficiency and will be described in our Fall 2015 article. Adjusting irrigation timing is a simple and cheap way to increase irrigation efficiency. Irrigating in the early morning hours can decrease losses to evaporation and drift, but will negate some of the plant growth benefits of irrigating in hotter parts of the day. By using cyclic irrigation — dividing the same irrigation volume into three separate events throughout the day — water has time to soak in (see Figure 1). Cyclic irrigation can decrease water use by 25% and prevent runoff, as well as increase growth. Refining irrigation volume is another easy way to irrigate efficiently. One method to refine the irrigation volume is by calculating the leaching fraction. The leaching fraction is the amount of water applied during an irrigation cycle that drains out of the container compared to the amount that is applied (easily defined as excess water). A leaching fraction of 10% to 20% allows for water and nutrient conservation. Our Fall 2015 article will describe how to determine LF. Basing irrigation on the soil or container-substrate moisture level is
another way to refine irrigation. Water in soil and container substrates is divided between plant-available water and unavailable water. A tensiometer is a probe-like device that can be used to determine the amount of water available to plants growing in field soil, which is very valuable, but generally does not perform well in container substrates, which are coarse in comparison to soil. Capacitance sensors determine volumetric water content, and while very useful, they do not account for the amount of water actually available to the plant. However, even without probes it is easy to determine irrigation volume needed by weight. Start by watering a plant thoroughly, let it drain to container capacity (when it stops dripping, usually after 30 minutes to 1 hour, depending on container size), and then weigh it. Reweigh it 24 hours later. The difference in weight is used to determine the water lost in one day. This water loss is a combination of evaporation from the substrate and the transpiration from the plant, what is collectively referred to as evapotranspiration. By knowing the system’s application rate and that 1 gram of water equals one milliliter of water (varies slightly by temperature), a grower can adjust the irrigation duration to precisely apply the amount of water lost in the previous 24 hours. A similar type of daily water-use system can be automated by using capacitance sensors to sense the change in water content each day and trigger irrigation solenoid valves to replace the amount lost in the previous 24 hours.
Summary Increasing irrigation efficiency can lead to many benefits, including shorter production cycles, decreased root rot and use of fungicides, and increased intervals between preemergence herbicide applications. The concepts described above range from very simple to using automated moisture-sensor-based irrigation systems. Consider trying one new technique this summer, and see what benefits you experience! C This article was sponsored by the Southern Risk Management Education Center, USDA NIFA and The University of Tennessee Institute of Agriculture.
In the landscape
By Susan Hamilton, Ed.D., Director of the UT Gardens; Beth Willis, Trials Coordinator; James Newburn, Assistant Director; Holly Jones, Kitchen Garden Manager; Jason Reeves, Curator of the Jackson UT Gardens; Carol Reese, Ornamental Horticulture Specialist; and Andy Pulte, Plant Sciences Faculty Instructor, The University of Tennessee
INCREDIBLE EDIBLES Brazelberries® ‘Peach Sorbet’ Blueberry, Vaccinium hybrid This is a relatively new blueberry cultivar from Fall Creek Nursery’s Brazelberry collection. Plump, sweet blueberries were only part of its appeal. New growth was a nice variety of peach, pink and pale-green, and fall colors ranged from purple to red. The robust compact plants stayed under 2' wide and 3' tall and were perfect for containers.
‘Juliet’ Tomato, Solanum lycopersicum ‘Juliet’ An extremely productive, indeterminate, hybrid plum-shaped cherry tomato, it had good flavor, and the fruit did not crack. The disease-resistant plants stayed green and full all season, with fruit ripening almost daily.
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Mizuna Mustard, Brassica rapa japonica Mizuna is a mild-tasting Asian green that can be eaten fresh, steamed, sautéed or boiled. It grew quickly from seed (20 to 40 days) and performed well in both summer heat and winter chill. In the UT Kitchen Garden, we have had some survive temperatures into the low 20s.
‘Prevail’ Bush Bean, Phaselous vulgaris This bush bean stood up to the heat of summer better than any other variety we have grown. It produced multiple crops of mildly sweet, tender, uniform pods and showed good disease resistance. The disease-resistant characteristic meant greater productivity, as well as a longer-lasting aesthetic value.
TREMENDOUS TREES AND SHRUBS Betula nigra ‘Little King’ Fox Valley™ River Birch This wonderful, dense and compact landscape-scale birch is more like an irregularly rounded-spreading large shrub than a tree, with interesting cinnamon-colored bark and an ideal size for use in a garden setting. It has dark-green foliage throughout the season. The pointy leaves turn an outstanding yellow in the fall. This can be a high-maintenance dwarf tree that will require regular care and upkeep, and it should be pruned only in summer after the leaves have fully developed, as it may “bleed” sap if pruned in late winter or early spring. Fox Valley River Birch will grow to be about 10’ tall at maturity, with a spread of 12'. It performs best in full sun to partial shade.
Caryopteris ‘Snow Fairy’ and Sunshine Blue®, Blue Mist Shrub Brighten up the landscape with these fall-blooming shrubs that have wonderful foliage interest. ‘Snow Fairy’ (shown) has an almost pure white variegation along the leaf margins. Compact growth habit (to 24") with deer-resistant leaves that tolerates full sun to partial shade makes this a must-have for the garden. Sunshine Blue® is a bit larger (2' to 3'), with golden foliage that retains that color even in the heat of summer. Flowers on both are an amethyst blue and are great bee and butterfly attractants.
Cercis canadensis ‘Little Woody’ ‘Little Woody’ is one of the most distinctive, compact eastern redbuds introduced to date. Distinguished by its thick, blue-green, large rounded, heart-shaped leaves that develop with extremely short internodes along the stems, it exhibits strong leaf texture and prominent veination. Before leaves emerge in spring, its brown branches become covered with clusters of small sweet pea-like flowers of rosy pink. This graceful, compact tree with a vase-shaped canopy makes a unique and excellent specimen plant. Preferring partial to full sun and a moist but well-drained soil, this moderately paced grower reaches up to 6' to 8' tall and 8' to 10' wide.
Hydrangea paniculata ‘Silver Dollar’ This hydrangea has strong stems and dense, white flowers that flush to pink from summer through fall. An RHS Award of Garden Merit winner, it reaches 4' to 5' wide and 5' to 6' tall, although it may potentially reach 8'. It is, though, more compact than some other cultivars of H. paniculata. It prefers full sun to partial shade. Not patented.
Ilex x ‘Whoa Nellie’, Gold Nellie R. Stevens Holly ‘Whoa Nellie’ was found by Dr. Mike Dirr on the University of Georgia campus and named by Tony Avent. New growth is bright gold and does not burn in the sun, while the inner growth retains a dark-green color. In 8 to 10 years, it should make a dense 12' tall by 8' wide pillar in a garden with average soil. ‘Whoa Nellie’ will produce an abundance of bright-red berries when a male pollinator is grown in the same area. ‘Edward J. Stevens’ works well as a pollinator. ‘Whoa Nellie’ works well as a focal point and will make a nice addition to any mixed privacy screen. Siting in full sun will ensure its best golden color. Zone 6.
Juniperus chinensis ‘Angelica Blue’ The bright-blue color of the fine-textured foliage is intensified by cool winter temperatures. It creates excellent texture and color contrast when mixed with dark-green-foliaged plants. Preferring a well-drained soil and full sun, it grows 3' to 5' tall and 5' to 10' wide.
tennessee greentimes SUMMER 2015
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In the landscape
REMARKABLE ROSES Cinco de Mayo™
Pumpkin Patch™
A floribunda rose with multiple blooms that were varying degrees of smoky coral-pink to dusty lavender on one cluster. AARS 2009 Winner.
Unique bloom color opened from a copper-colored bud to a caramel-orange bloom that then lightened with age.
‘Good As Gold’ A new introduction of hybrid tea that had a rich, orange-gold to yellow-gold color that finished with a light margin of pinkish red.
Love and Peace™ A visitor favorite, this hybrid tea had a bushy habit, resulting in lots of blooms of soft yellow and rich pink.
Tahitian Treasure™ Rosa ‘Radtreasure’ Introduced last year by Star Roses, this was a breakthrough in breeding, as it is a grandiflora that performs like a landscape rose. Trialed as a potential introduction in the UT Gardens, we had our eye on this rose for a couple of years. It was truly amazing, and we’re excited it has been introduced to the market. It’s an outstanding re-bloomer with a beautiful, rich, pink bloom color, great flowering density and good growth habit, and it’s very disease resistant. This rose has it all.
Vavoom™ We included this floribunda again because it was consistently a visitor favorite and about as orange as you can get in a rose. A ‘Big Orange’ orange. C
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In the Nursery
Pick Your Pot‌ Are Container Alternatives Right for Your Growing Operation?
By Susmitha Nambuthiri, Ph.D., University of Kentucky; Amy Fulcher, Ph.D., University of Tennessee; Robert Geneve, Ph.D., University of Kentucky; Genhua Niu, Ph.D., Texas A&M; Diana Cochran, Ph.D., Iowa State University; and Sven Verlinden, Ph.D., and Renee Conneway, West Virginia University
P
lastic has been the predominant container material in the U.S. green industry because plastic containers are available in many sizes, shapes and colors and are relatively inexpensive. Currently, production of ornamental plants consumes an estimated 1.66 billion pounds of plastic every year (Photo 1). The sheer volume of plastic consumption poses many problems, from limited access to recycling centers, high collection costs, liability for poorly sanitized containers and chemical-contamination concerns. Not surprisingly, 98% of used plastic containers are disposed of in landfills. Consumers are questioning the use of plastic products as a sustainable practice in a truly “green� industry, and some consumers are even willing to pay a premium for non-plastic or recyclable containers. Meeting this consumer interest gives growers and retailers an opportunity to offer more eco-friendly products.
Available choices Growers have a range of alternative container types to select from, each with slightly different characteristics (Photo 2). Plantable containers can be planted directly into the soil by the end user. These containers are intended to withstand watering and handling during relatively short-term production (approximately 12 weeks to 12 months, depending
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on climate, production practices and container material). Plantable containers eliminate container removal and disposal costs and reduce the time required for transplanting and cleanup at installation by 20%, which can be a big boon to landscape customers. Examples of plantable container materials include: composted cow manure, paper, peat, rice hulls, rice straw, spruce fibers, wheat or wood pulp. A second container type is compostable containers, which are removed at installation, and the containers are either composted in backyard or industrial facilities, which consumes energy. Most bioplastics, as well as solid rice hull, keratin and thick-walled paper and/or cardboard-based containers intended for a production duration of approximately a year, fall into this category. Some containers marketed as compostable did not meet de-gradation standards during our trials, but for simplicity we refer to them as compostable. Containers made from recycled plastic, water and soft drink bottles blended with biodegradable natural fibers, such as cotton, jute, vegetable fibers or bamboo, are neither plantable nor compostable but disintegrate slowly. These containers have a reduced carbon footprint compared to plastic containers made entirely from petro-chemicals. Because not all of these containers are made from 100% biodegrad-
able materials, we refer to them as alternative containers rather than biocontainers.
Production trials As alternative containers gain popularity, growers and retailers question what to expect from them during a production and marketing cycle. Researchers from Arkansas, Illinois, Kentucky, Michigan, Mississippi, Tennessee, Texas, Utah and West Virginia have been working on a USDA Specialty Crop Research Initiative project to evaluate alternative containers during and after greenhouse production and aboveground and pot-in-pot nursery production. Containers tested during greenhouse production and subsequently tested during landscape establishment include: recycled paper and cardboard (Western Pulp, Fertil Pot), cow manure (CowPot), straw (StrawPot), rice hull (NetPot), peat (JiffyPot), coir and bioplastic (SoilWrap). The aboveground nursery containers (1-gallon) tested were: recycled paper and cardboard (Western Pulp, Kord Fiber Grow), chicken-feather-based keratin, coir and recycled plastic (Root Pouch). Containers tested for pot-in-pot production were two types of recycled paper and cardboard (Western Pulp, Kord Fiber Grow). Researchers examined water use and rootzone temperature associated with alternative containers; assessed container
Section Name and plant performance, both during production and after planting in the landscape; tested container strength, durability and appearance; and conducted economic and environmental analyses of production using alternative containers. The following represents a portion of the results. Comprehensive, detailed research results are available in an alternative container special issue of HortTechnology published in February 2015.
Photo 1. The green industry generates an estimated 1.7 billion pounds of plastic waste each year. (Photo by Amy Fulcher, Ph.D., University of Tennessee.)
Trial results Numerous herbaceous and woody plants species were grown in alternative and black-plastic containers in greenhouses and nurseries with little or a positive effect on growth and plant quality at most test locations. The porous nature of wood pulp and fabric containers allowed evaporative cooling, reducing potting substrate temperature by about 11ºF during aboveground nursery production compared to blackplastic containers, which increased plant survival under hot summer conditions. Not surprisingly, porous alternative containers used, on average, 20% to 40% percent or more water, which could erode the economic feasibility and environmental sustainability of alternative containers, particularly in regions with perpetual water shortages (Photo 3). Keratin containers, which are slightly smaller and lighter in color, used less water than plastic. Alternative nursery containers had good durability under typical growing conditions and even after overwintering. In other studies, biocontainers (e.g., molded fiber, cow manure, peat) used for more than six to eight weeks of production in the greenhouse had algal and/or fungal growth and became fragile, reducing aesthetic qualities and shipping and handling properties. These containers may be best suited for short-term greenhouse production and subsequent landscape planting rather than retail sales. This is the tradeoff between durability and biodegradability, but one that environmentally conscious producers may be willing to accept. Following some of the production trials, ‘Sunpatiens Compact Magenta’, New Guinea impatiens, ‘Luscious Citrus’ lantana and ‘Senorita Rosalita’ cleome
Photo 2. Containers made from coconut coir (marketed as plantable) and recycled paper and cardboard (marketed as compostable) are compared with black plastic containers. (Photo by Robert Geneve, Ph.D., University of Kentucky.)
Photo 3. Some containers with porous sidewalls required more water than traditional black plastic containers. (Photo by Robert Geneve, Ph.D., University of Kentucky.)
In the Nursery
grown in plantable containers were installed in the landscape. At the end of the season, manure-based containers had nearly completely degraded (88%), while straw, wood fiber, soil wrap, peat, coir, and rice hull degraded 18% to 47%. Even at the low end of the range of container decomposition, plantable containers did not hinder plant establishment after planting into the landscape. In isolated cases, plants in straw and coir containers were smaller than plants in other containers but still grew to an appropriate size in the landscape.
Additional comments Container type is one of the most visible and recognizable sustainable changes that growers and retailers can make. However, depending on petroleum prices, alternative containers can be more expensive, typically 10% to 50% more than their plastic counterparts. An increased cost means that growers must be able to realize a price premium or reduce production costs. A recent study showed that consumers found plants grown in 4" recyclable, plant-
able and non-plastic (i.e., compostable) containers to be worth an additional $0.16, $0.12 and $0.23, respectively. Certain segments of the population will pay a price premium greater than those listed, so depending on the end consumer demographic, the reward for adopting alternative containers can be greater. Other studies report an increased customer demand for biodegradable containers compared to the traditional plastic container. Similar to results from groundcover production in Quonset huts and some of our greenhouse studies, John Ruter at the University of Georgia found that ‘Aztec Gold’ daylily grown in fiber containers produced more fans than those grown in plastic containers. ‘Otto van Luyken’ laurel was 53% larger, and survival was double, in a fiber container compared to a black-plastic container. Growers, especially those in southern locations, may want to try porous, alternative containers to see if they shorten the production duration and/ or improve survival, increasing the cost effectiveness of alternative containers.
Consumers are becoming increasingly interested in the green industry’s impact on the environment and the impact of their own purchasing decisions. Using containers made of alternative materials can be good for production and for the bottom line. As with plantable containers for landscape contractors or evaporative cooling in hotter locations, there may even be some value-added aspects of alternative containers. However, growers must consider the potential increase in container cost, inability to reuse and increased water use for some containers and any changes in their production that may need to be made to successfully integrate alternative containers. C The authors wish to recognize the USDA (Specialty Crops Research Initiative Grant number 2010-01190) and their respective land grant institutions for support for the research reported in this article. Editor’s Note: This article originally appeared in Nursery Management, March 2015, www.nurserymag.com.
Index of Advertisers
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Calendar of Events
July 19–21
PLANET Legislative Day on the Hill Washington, D.C. Contact: 800-395-2522 www.landcarenetwork.org
July 21–23
SNA 2015: Research Conference, Perennial Plant Conference & Tradeshow (Southern Nursery Assn.) Georgia International Convention Center Atlanta, GA Contact: 678-809-9992 mail@sna.org www.sna.org
July 27—August 1
August 12–14
Perennial Plant Symposium Hilton Baltimore Baltimore, MD Contact: 614-771-8431 Email: ppa@perennialplant.org www.perennialplant.org
Summer Green Road Show (NC Nursery & Landscape Assn.) Hickory Metro Convention Center Hickory, NC Contact: 919-816-9121 https://ncnla.memberclicks.net
July 29–30
September 10
Penn-Atlantic Nursery Trade Show (PANTS) Pennsylvania Convention Center Philadelphia, PA Contact: 723-449-4004 www.pantshow.com
University of Tennessee Turf & Ornamental Field Day University of Tennessee Knoxville, TN
September 17–18
Tennessee Green Industry Expo To be held in conjunction with The Middle Tennessee Nursery Association (MTNA) Music City Center Nashville, TN Contact: 931-473-3951 Fax: 931-473-5833 Email: mail@tnla.com www.tngie.com
October 10–14
IPPS Southern Region Annual Meeting Tampa, FL Contact: 803-743-4284 Email: scplant@bellsouth.net ipps-srna.org
October 21–23
PLANET Green Industry Conference Louisville, KY Contact: 800-395-2522 www.landcarenetwork.org/GIC
October 22–24
GIE+Expo – Green Industry Equipment Expo and School of Grounds Management Kentucky Expo Center Louisville, KY Gie-expo.com/gieexpo
November 6–9
ASLA – Annual Meeting & Expo (American Society of Landscape Architects) McCormick Place Chicago, IL Contact: www.asla.org