Sustainable Small-ScaleATTRA Nursery Production    A Publication of ATTRA - National Sustainable Agriculture Information S...
• Lawn and garden centers draw                     • Mass merchandisers want large volumes of a                           ...
Table 1. Types of nurseries                              plants. A concerted effort at the federal                        ...
Container and field production will be dis-  Grower profile: Santa Ana Garden Center and Santa Ana                         c...
Table 2. Comparison of water systems for container nursery stock (7)                                         Overhead spri...
of ornamentals grown in 2.8-liter contain-      practices. The researchers recommend                 ers, the mean relativ...
Container production                              NCAT’s Organic Crops Workbook and otherA wide selection of ornamentals i...
Copper-treated fiber pots, made from recy-        strong tap-rooted species such as black wal-                        cled ...
A container system that emphasizes hardy, fibrous roots   Cherry Lake Tree Farm in Groveland, Fla.   Inc. (17). Larger line...
Hand weeding is costly, but it may be appro-                 Alternatives to herbicides                                   ...
weeds than corn gluten meal (24) and can         Final Rule, more nursery growers explorebe applied at less than half the ...
Table 3. Analysis of organic and synthetic slow-release fertilizersOrganic fertilizers         %N             %P          ...
Table 4. Materials for organic fertigation*Element                      Material                                       Ben...
nutrients are deficient and must be incor-                  porated into the plant quickly. Use fi ltered      Chris Starbuc...
mass plantings, inexpensive establishment       The advantages of field grow bags areand large caliper (trunk diameter) si...
implements including a brush hoe for preci-     inches wide, from 1/2 inch to 10 inches                       sion weeding...
Table 5. Organic mulchesType                            Source of weeds           CommentsGrass clippings                 ...
Harvest and storage                                    • Prices and quantities offered by                                 ...
Sustainable Small-scale Nursery Production
Sustainable Small-scale Nursery Production
Sustainable Small-scale Nursery Production
Sustainable Small-scale Nursery Production
Sustainable Small-scale Nursery Production
Sustainable Small-scale Nursery Production
Sustainable Small-scale Nursery Production
Sustainable Small-scale Nursery Production
Sustainable Small-scale Nursery Production
Sustainable Small-scale Nursery Production
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Sustainable Small-scale Nursery Production

  1. 1. Sustainable Small-ScaleATTRA Nursery Production A Publication of ATTRA - National Sustainable Agriculture Information Service • 1-800-346-9140 • www.attra.ncat.orgBy Steve Diver and Sustainable nursery practices can increase plant marketability and reduce a nursery’s impact on theLane Greer environment. This publication focuses on the sustainable production of woody and herbaceous nurseryUpdated June 2008 plants, both in containers and in the field. It is not a primer for inexperienced growers, but a comple-by Katherine L. Adam mentary source of information that concentrates on sustainable production techniques. Topics coveredAgriculture Specialist include integrated pest management, weed control and alternative fertilizers. The publication also© 2008 NCAT introduces business management practices.Contents IntroductionMarketing ......................... 2 This publication is for small-scale nurs-General ery managers who want to use sustainableproduction ....................... 3 practices and large-scale nursery managersIntegrated pestmanagement .................. 6 interested in converting from conventionalContainer to sustainable practices. In this publication,production ....................... 7 small-scale defines a nursery with fewerField than five acres in container production andproduction ..................... 14 fewer than 15 acres in field production. ThisCosts.................................. 18 publication does not include everything aSummary ......................... 19 nursery manager needs to know before goingReferences ..................... 19 into production.Resources ....................... 21 A nursery can be part of a diversification strategy to make a farm more profitable or a nursery can be a sole enterprise. In either case, it is important to start small and expand later. For general information on standard nursery production, please refer to publications and bulletins published by the Rows of greenbean beanstalks. Photo by Jandre Venter Cooperative Extension Service and common horticultural texts and trade magazines. See the Resources: Publications section Department of Agriculture National Agri- at the end of this document for a listing of cultural Statistics Service fi gures show a nursery literature. slight increase over 2006 in wholesale value of U.S. floriculture crops, the largest seg- Sustainable nursery practices aim to reduce ment of the nursery industry (1a). The most levels of synthetic fertilizers and pesticides, important things to consider before start- use integrated pest management systems to ing production are what crops to grow andATTRA – National SustainableAgriculture Information Service is deal with insects, diseases and weeds and how to market them. In today’s economy, itmanaged by the National Center for focus on building the soil to promote plant is no longer possible to grow crops withoutAppropriate Technology (NCAT)and is funded under a grant health. This document discusses sustain- fi rst considering the crop’s marketability.from the U.S. Department of able nursery production in general before Here are some facts to keep in mind beforeAgriculture’s Rural Business-Cooperative Service. Visit the moving to sustainable container and field starting out:NCAT Web site ( production techniques.sarc_current.php) for • Container-grown crops generatemore information onour sustainable agri- The nursery industry appears to be hold- about 10 times more sales per acreculture projects. ing its own through 2007. The latest U. S. than field crops (1).
  2. 2. • Lawn and garden centers draw • Mass merchandisers want large volumes of a approximately 80 percent of their few popular plant species. Mass merchan- customers from a 5- to 15-mile disers purchase smaller plants. These cus- radius (2). More than 60 percent tomers may not care about buying specific of an average wholesale nursery’s plants, but focus on obtaining a good mix sales are to customers from within of fast-moving materials. Demand from the state. Small nurseries sell about these customers is seasonal (1). Plants in 20 percent of their plants to out-of- fashion vary from year to year. state customers (1). • Retail garden centers usually want There are several disadvantages to deal-Related ATTRA small plants in 1- to 3-gallon con- ing with mass merchandisers. These cus-Publications tainers. Landscaping firms and tomers want instant shipment, pay theSolar Greenhouse landscapers want larger container lowest price for plants and often do notResources (Web only) plants in 3- to 5-gallon containers take care of plants after receiving them, and balled and burlapped woody which can reflect poorly on a nursery.Renewable EnergyOpportunities on plants. • Landscapers look for large, high-qualitythe Farm • The nursery industry is dependent specimens carefully identified by cultivar.Energy Saving Tips on the construction industry and Landscapers generally want to buy plantsfor Irrigators on the rate of unemployment in the from a limited number of producers but vicinity of the nursery (1). also want to choose among many plantsWoody Ornamentalsfor Cut Flower and plant sizes. Landscaper purchasesGrowers Marketing are spread out through the year, with anPhenology Web Links: Before entering the nursery business, a mar- emphasis on spring planting (1). Horticul-Sequence of Bloom, ket analysis is necessary to determine what ture degrees with specialization in land-Floral Calendars, opportunities exist to sell plant materials in scape architecture were popular careerWhat’s in Bloom the local area. Most new fi rms begin with choices in the 1980s and 1990s, creating(Web only) only a few acres of production and market a solid base for nursery customers.Agricultural Business in a 50-mile radius, unless growing for mailPlanning Templates order or on contract (1). A market analysis • Lawn and garden centers fall somewhereand Resources includes finding out what crops other nurs- between the mass merchandiser and theBiointensive eries grow successfully in the region. The landscaper. Some centers want variety inIntegrated Pest analysis also evaluates competition potential plants and plant sizes, some do not.Management from area nurserymen. When considering the market, bear in mind this advice from Other retail outlets include mail order, WebNematodes: Lynn Byczynski, editor of Growing for Mar- sites, farmers’ markets and starting a land-Alternative Controls ket, a newsletter for small-scale producers: scaping business. Sales at farmers’ marketsUse of Baking Soda as will be local, but local can mean weekly “I feel quite strongly that it is a serious mis-a Fungicide take to commit to growing for anyone before travel of 200 to 300 miles to a large metro-Notes on you have become extremely confident of your politan area. Potential customers all shareCompost Teas skill as a grower. My recommendation for a common need to get uniform, well-grown marketing is a simple one: Start where no plants from a producer without having toIntegrated Pest one is depending on you. If you have nothingManagement for to sell, no one will have to know”(3). inspect the crop before each purchase (1).Greenhouse Crops Marketing starts with a decision about what 2) Keep up with trends in buyer preferences. to produce and at what volume. Nursery Constant monitoring of customer character- managers need to: istics and purchases is crucial. Advertising 1) Determine what kind of customer the nurs- and promotion never end. Chain stores now ery will attract and what size of plants those carry nursery items. Convenience and esca- customers want. lating gas prices promote one-stop shopping.Page 2 ATTRA Sustainable Small-Scale Nursery Production
  3. 3. Table 1. Types of nurseries plants. A concerted effort at the federal level to limit introductions of plant speciesType Description to the United States raised concerns on theGrower/retail Grows and sells plants part of some plant explorers and nurserynursery on-site owners. However, it encouraged renewedWholesale Grows plants for sale to interest in native species formerly put at anursery other nurseries, disadvantage by foreign imports, not only for landscapers or retailers, in situ conservation, but also for increased may grow plants on a contract basis use in landscaping. Several plants on inva- sive lists throughout the United States areLandscape Provides landscape important to the nursery trade. Plants suchnursery services and retail sales as Norway maple, butterfly bush, JapaneseFarmers’ Grows plants to sell locally barberry and miscanthus have been lucra-market at retail prices tive sellers (4).Mail order/ Grows plants to sell at theWeb site national level* The USDA now maintains a Web site on*Note: Recent legislation made it easier for states to invasive flora and fauna species at www.collect sales tax on Internet sales. The National Park Service provides plant fact sheets and a helpful list of natural area invaders at www.3) Know what combination of plants will Consulting such lists is maximize profits. advisable when making decisions on offer- ing nursery stock to the public.Ornamental plants fall into general catego-ries of shade trees, conifers, perennials,vines, shrubs, bulbs and annuals. Whilemost nurseries grow a range of plants, thereis a trend toward specialization. Growingonly native groundcovers or only dayliliesare viable niche markets. The production ofspecialty crops, such as hardy bamboo anddisease-free apple stock, and specializationin plants in short supply, like uncommonplants and very large trees, are niche mar-kets even small growers can serve.Keep abreast of recent developments inthe industry. Subscribing to trade publica-tions and attending trade shows or confer-ences are good ways to learn about growerissues like plant availability, new varietiesfor specific needs, popular sizes, specificgrowing conditions and enhanced services. General productionEnhanced services can include providing There are two types of nursery production:photographs of plants and making presen- field and container. Field stock is eithertations to landscape architects and other direct-seeded or transplanted from seed-potential customers. lings and then lifted as bare-root stock for use as nursery liners, fruit trees, seed-Invasive species lings for Christmas trees, windbreaks andThe USDA and other government agencies conservation plantings. Field stock is alsoare increasingly concerned about invasive grown for balled and burlapped landscapeplant imports. Drug enforcement personnel or shade trees. Container stock, which isare also concerned about the use of some propagated from seed, rooted cuttings ATTRA Page 3
  4. 4. Container and field production will be dis- Grower profile: Santa Ana Garden Center and Santa Ana cussed separately, but there is commonality Native Plant and Tree Nursery between the two forms of production. Most The Santa Ana Pueblo, a small suburb of 497 residents, is located two woody landscape plants, regardless of how miles north of Albuquerque, New Mexico. The town is home to a retail they are grown, are propagated by cuttings. nursery and a wholesale nursery that supply plants and trees that thrive Both types of production require spending under arid local conditions. The Pueblo of Santa Ana Tribal Enterprises a high percentage of a nursery’s budgets on operates the retail Santa Ana Garden Center and the wholesale Santa farm-type mechanized implements and fer- Ana Native Plant and Tree Nursery. tilizers (1). Since tribal water rights to the adjacent Rio Grande take precedence, the garden center and nursery, along with a tribally operated golf course, Soil productivity is not as important when greatly enhance landscaping and recreation options for Albuquerque growing only containerized products, but and area residents. relatively level land with good drainage is still necessary. Beginning nursery manag- The Santa Ana Garden Center and Santa Ana Native Plant and Tree Nursery maintain Web pages on the Pueblo of Santa Ana Tribal Enter- ers must learn the length of time required prises Web site, The pages list more than 250 plant to produce marketable crops and how to species, most grown from locally collected seed. The lists, organized schedule planting so the proper number of alphabetically by scientific name, function only as a reference to what each species is available for the first year of the venues stock. Plants must be picked up on-site since the stores are sale and following years (1). not mail-order businesses. The Santa Ana Garden Center offers a large selection of drought-toler- Irrigation ant flowering native plants, shrubs and ground covers for xeriscaping and trees with low watering requirements. It also stocks native grasses The two most widely used irrigation systems for lawns or reclamation, herb and vegetable starts, wildflower seed, are overhead and drip or trickle systems. organic products, drip irrigation supplies, seasonal gift items and books. Overhead irrigation systems are designed The store can also advise customers about plants for rock gardens, to cover a large area and these systems are windbreaks, natural hedges, barriers, erosion control, wildlife habitat, the least expensive to install. However, this food and medicinal uses. method produces uneven water distribution, Respect for tribal customs and the earth are strongly encouraged when which can slow plant growth, encourage dis- visiting the nursery and garden center. Taking photographs at the sites ease and contribute to runoff. A container is restricted, but images at the tribal Web site, nursery using overhead irrigation can use nursery.htm and, give an idea of how from 15,000 to 40,000 gallons of water per some plants are started in hoophouses with supplementary heating acre daily in the summer (6), a reminder during the chilly north-central New Mexico winters (5). that sufficient water is a prerequisite to nursery production. Large containers are usually watered with a field-grown seedlings, is common in both drip or trickle system, which uses 60 to 70 forestry and landscape nursery production. percent less water than an overhead system. Drip irrigation systems cost more to install Fifty years ago, nursery managers grew but have superior application uniformity ornamental plants in the field and dug the and efficiency. Drip irrigation systems are plants up later for transplanting. Today, 80 also affected less by wind and crop canopies percent of ornamental plants are container- and produce less runoff. Another advantage is that workers can continue working while grown. The switch occurred for several rea- the plants are being irrigated. The biggest sons. Container-grown trees have a greater disadvantage to a drip or trickle irrigation chance for survival and establishment after system, besides the initial cost, is keeping transplanting. Containerized production the pipes and emitters clean. does not require good soil and takes up less A third, less-used type of irrigation system acreage. Containerized stock also enables is subirrigation using capillary sandbeds. In the grower to extend the planting season. this system, water rises into containerizedPage 4 ATTRA Sustainable Small-Scale Nursery Production
  5. 5. Table 2. Comparison of water systems for container nursery stock (7) Overhead sprinklers Drip or trickle irrigation Capillary beds tubesInstallation cost/acre Moderate Moderate to high HighMaintenance Low High HighDurability Excellent Low ModerateLabor Low Moderate to high LowWater distribution Fair Fair to good* GoodWater use efficiency Poor, very wasteful Good GoodPump required Large, high pressure Small, low pressure Small, low pressureWater volume required Large Small SmallWind effect on distribution Serious None None*If ground is level and water quality is goodplants through capillary action. The sandbed Out, see the Container production sec-is covered with at least 1 inch of fine sand tion. For distribution information, see theand slopes very slightly. Water is released at Resources: Suppliers section. For a list ofthe high end and slowly percolates to the low articles related to sandbeds and subirrigationend. These systems cost the most to install, systems, see Resources: Publications.but have no runoff or leaching. Plants need to be watered often, especiallySandbeds are normally built using wood during hot, sunny days. A typical nurserysidewalls, a plastic bed liner, sand, a small plant in a 1-gallon container can consumetank, a drainpipe and a float valve. Sand- a pint of water a day, while the growingbeds do not require the use of any electrical medium capacity may be only 1.5 and provide a uniform and consistent One important aspect of irrigation manage-supply of water without forming a saturated ment is to group plants according to waterwater table at the base of the soil column the container. Sandbeds offer efficientand uniform crop growth while providing Irrigation runoffless water, less fertilizer and less pesticide. The most important issue with irrigationSandbeds also require less labor since in sustainable nursery production is water,sprinkler heads, timers, pumps, valves and fertilizer and pesticide runoff. Many stateswater-treatment systems don’t need to be now have regulations limiting runoff andmonitored (6). groundwater nitrate levels.The biggest disadvantage of sandbeds is Subirrigation systems are designed to elim-that weeds and containerized plants grow inate runoff, but overhead and drip orinto the structure. The Agroliner is a retail trickle systems may require special atten-product designed to alleviate this prob- tion. Ditches planted with grass to slowlem. The Argoliner is a mat treated with down water flow or tile systems that directSpin Out, a copper paint that prevents water to a pond or other holding area canroot growth and is registered by the Envi- collect runoff water.ronmental Protection Agency. The mat is The water and some of the fertilizersplaced over the sand and under the con- present can be recycled by pumping watertainers. back out of the holding tank or pond afterGriffin LLC, a supplier of crop protection impurities like sand and silt settle out.chemicals in Valdosta, Ga., sells Spin Out. Recycled water can improve plant growth.For more information on ways to use Spin In experiments with more than 100 ATTRA Page 5
  6. 6. of ornamentals grown in 2.8-liter contain- practices. The researchers recommend ers, the mean relative growth of plants irri- using lower amounts of N fertilizer—about gated with continuously recycled water was 50 milligrams per liter—and providing 103 percent of the control (8). sufficient moisture. Pulse irrigation is another way to reduce Several Extension bulletins and other pub- runoff. In this system, a small amount of lications that deal with irrigation runoff water is applied five or six times a day, issues are accessible on the Internet. See instead of one heavy watering daily. Very the Resources: Web sites section for more little water escapes from the container or information. runs off from the field. Less fertilizer is applied because there is less leaching. Most nurseries that use this system use a com- Integrated pest management puter to control water flow, since watering Integrated pest management is an ecologi- plants repeatedly by hand causes a huge cally based pest control strategy that is part increase in labor expenses. of the overall crop production system. It is called integrated because all appropriate There are several cultural practices that can methods from multiple scientific disciplines reduce runoff: are combined into a systematic approach • Avoid irrigating bare soil for optimizing pest control. Management • Have rough soil surfaces to provide implies acceptance of pests as inevitable surface storage of water components at some population level in the agricultural system (11). • Use less-porous media that retain moisture and nutrients An integrated pest management program involves using resistant cultivars, build- • Use slow-release fertilizers instead of liquid fertilizers ing up populations of beneficial organisms, monitoring numbers of pests, developing Researchers at The Ohio State Univer- treatment thresholds and using spot treat- sity conducted experiments to reduce the ments of pesticides that are the least harm- amount of pesticides and growth regula- ful to beneficial organisms and the environ- tors leached from nursery pots and trays. ment. It is important to identify pests early Researchers had excellent success mixing so nursery managers can take appropriate chemicals in ordinary latex paint and then measures quickly. painting the interior of the pots. The pots leached less and the growth regulator and There are numerous publications available pesticide researchers used, commercially from the USDA’s Cooperative Extension available brands Bonzi and Marathon, pro- Service that deal with integrated pest man- vided more consistent control. This method agement for nurseries. See the Resources also reduced worker re-entry intervals in section for more information. the nursery area, since workers apply chem- icals once at the beginning of the growth process (9). Reducing moisture stress enhances growth ATTRA publications on nursery- related pest management topics more than increasing fertilizer concentra- tion, a study conducted in the late 1990s Biointensive Integrated Pest Management found (10). This study, also conducted at Nematodes: Alternative Controls The Ohio State University, used fertilizer Use of Baking Soda as a Fungicide concentrations between 50 and 200 milli- Notes on Compost Teas grams per liter of nitrogen. The research- Integrated Pest Management for ers showed that water stress might limit Greenhouse Crops growth more frequently than limited nutri- tion under current container productionPage 6 ATTRA Sustainable Small-Scale Nursery Production
  7. 7. Container production NCAT’s Organic Crops Workbook and otherA wide selection of ornamentals is produced ATTRA publications. For information aboutin containers. Homeowners usually prefer to whether a commercial product is permitted,buy containerized plants because the plants restricted or banned in organic produc-are easier to transport and transplant than tion, consult the Organic Materials Reviewballed and burlapped plants. The follow- Institute Web site at section summarizes some importantcontainer production practices and Containersaddresses sustainable nursery management There are several factors to keep in mindissues like recycling plastics, weed control when deciding what containers to use. Fac-and fertilization. tors include cost, design features that con-The advantages of containerized production trol root growth, durability, shipping capac-include: ity, availability, how the container affects growing medium moisture content and tem- • Achieving high plant densities perature and how the container suits the • Using land unsuited for field particular needs of the nursery. P production ots and Round, black plastic pots are the industry • Planting at times independent of the standard, but can cause root constriction containers weather that leads to plants with poorly developed designed • Eliminating some operations, like root systems. There are other kinds of con- for enhanced root root pruning tainers that promote better root systems. growth are an • Lowering transportation costs Copper-lined, white and light-colored con- important feature in because of lightweight media tainers all produce more root growth and square and stair-step pots help keep plants containerized nurs- • Experiencing less root loss and a from becoming root-bound (1). ery production. greater chance of survival than with field-grown trees Pots and containers designed for enhancedThe disadvantages are also numerous: root growth are an important feature in containerized nursery production. Each pot • Small containers need frequent and container offers its own advantages and watering disadvantages. • Nutrients deplete rapidly • Plants require winter protection Copper • Plants easily become root-bound Foresters discovered that copper can con- trol root growth. Copper kills root tips that • Wind can knock over trees come in contact with it, forcing roots to • Containers are costly branch within the root ball instead of cir- • Labor costs to pot up plants are cling around it. high Plants grown in copper-treated containers • Temperature extremes stress roots are taller, less root-bound and have higherGrowing certified organic nursery stock transplant survival rates. Plants grownintended for sale to vineyards, berry farms in copper-treated containers also haveand orchards raising organic produce is a increased nitrogen recovery and requireniche market that requires special atten- fewer applications of nitrogenous fertilizer.tion. Restricted products include common More than 120 species perform better iningredients in conventional nursery produc- copper-treated containers versus untreatedtion like chemical fertilizers, wetting agents, containers. Copper-treated pots also do notherbicides and synthetic insecticides and leach or leach very little into groundwaterfungicides. For more information, refer to or ATTRA Page 7
  8. 8. Copper-treated fiber pots, made from recy- strong tap-rooted species such as black wal- cled paper, are biodegradable and can nut, pecan and pines for Christmas trees. even be composted. The main problem with There are other types of containers that fiber pots is that the pots can degrade too promote excellent root branching and dis- quickly. Research at The Ohio State Univer- courage root circling. RootMaker, devel- sity showed that incorporating copper into oped by Dr. Carl Whitcomb at the horticul- fiber pots can increase their longevity (12). ture research company Lacebark, Inc., is a Dr. John Ruter at the University of Georgia pot that encourages root branching. Root- found copper-treated fiber pots keep roots Maker pots have staggered walls and a stag- cooler in the summer, increase root dry gered bottom, which prevent root circling weight and shoot dry weight of several spe- and direct roots toward holes in the walls cies and can withstand shipping (13). and bottom of the pots. Whitcomb, formerly Griffin LLC, a supplier of crop protection head of the nursery research program at chemicals in Valdosta, Ga., offers a product Oklahoma State University, is well known called Spin Out, a copper paint registered by for his numerous innovative approaches to the EPA. Root Right pots are round, black unusual container systems. plastic pots manufactured with Spin Out as aG rowing tree component of the container walls. For more Tubes seedlings in information on Spin Out and Root Right pots, Long bottomless tubes are another produc- contact the Lerio Corporation (14). bottomless tion system that uses air root pruning. Tubespaper-based milk are generally made of plastic or Styrofoam. Bottomless pots Nurserymen can use single tubes or severalcartons is one way touse air root pruning. Air root pruning is another way to prevent tubes imbedded in a flat. Tube plants range root circling. Air root pruning employs a in size from large plugs sold as nursery lin- similar mechanism to copper-treated pots. ers to seedling trees grown in long, narrow Root tips that come in contact with air are pots and sold directly to consumers. Tubes killed and the root system branches out are popular because they allow massive plant within the root ball. quantities to grow in a small area. Tubes are particularly adaptable to small-scale nurs- Growing tree seedlings in bottomless paper- ery production and to specialized stock like based milk cartons is one way to use air perennials and tree seedlings. root pruning. The milk carton, when folded open, creates a long, bottomless container. For more information on containers, see The These containers are placed in a wooden Container Tree Nursery Manual, Volume 2, by fl at with a wire-screen bottom and then Landis et al., listed in the Resources: Pub- fi lled with a soilless nursery mix. Another lications section. For suppliers of unusual option is to place tree seedlings in plastic pots, see the Resource: Suppliers section. milk crates. The taproot grows downward and out through the bottom of the container. Pot-in-pot system The root tip is exposed to the air, desiccates The pot-in-pot production method alleviates and dies back. some of the problems associated with con- Repeated air-root pruning stimulates lateral tainer production, such as blow-over and branching and results in a fibrous root sys- moisture loss (15). This system involves tem as opposed to a strong taproot system. burying a holder pot, or moat pot, in the The benefit to the tree is rapid establishment ground and placing a containerized plant in the field or landscape with increased inside this pot. The main drawback to this scaffold branching and top growth. Nursery system is the high initial cost of the moat stock production by the milk carton method pot. The moat pot is a long-term investment is especially useful for on-farm tree produc- since it will last 15 years or more. For more tion and can be used in the propagation of information on pot-in-pot systems, see the a wide range of woody plants, including articles listed in the Resources section.Page 8 ATTRA Sustainable Small-Scale Nursery Production
  9. 9. A container system that emphasizes hardy, fibrous roots Cherry Lake Tree Farm in Groveland, Fla. Inc. (17). Larger liners are planted in pruning fabric developed by Cherry developed a better way to grow con- Tree Bands, available from Anderson Lake and manufactured by Root tainerized trees (16). Their patented Die and Manufacturing (18). Before Control, Inc. in Oklahoma City (19). The Root-Enhancement System focuses planting, all the trays are sprayed with fabric lowers root zone temperatures on growing trees with a fibrous, lateral Spin Out, a copper paint registered by and prunes roots. root system. the EPA. When the trees reach an appropriate In the first stage, small liners grow in The liners are inspected before size, workers place them in pot-in-pot Deep Groove tube cell-pack trays of 38 potting. Workers cull liners with weak containers or transplant the trees into or 51 cells. The cells are cone-shaped root systems and place the rest in growbags. Finally, workers put the trees and lined with four vertical ridges that 1- or 3-gallon containers. These pots in a Spin Out-treated container in prep- guide plant roots to a large hole at the contain grids that sit about 1 inch aration for sale. bottom. These trays sit on benches in above the bottom of the pots and For a video of how this system works, the greenhouse. air-prune the roots. Container sleeves visit the Cherry Lake Tree Farm at www. Deep Groove tube cell-pack trays also hold the roots. The sleeves are available from Growing Systems, are made of a reusable geotextile Airpot.htm.Recycling plastic Many recyclers require nurseries to gather a certain amount of plastic before sendingMost nurseries use lots of plastic in the form a truck to pick it up. Smaller nurseries mayof pots, flats, hanging baskets and green- have trouble storing a large amount of plas-house fi lm. The nursery can reuse some of tic. Try combining plastic waste with otherthese products, but it’s important to have growers in the community. Some recyclersa recycling system in place. Buying multi- will not pay the grower for the plastic but doyear, ultraviolet-stabilized greenhouse fi lm not charge for transportation costs, whichdecreases the amount of sheet plastic used are often high.each year, but this kind of film is very expen-sive and not always readily available (20). Weed controlFortunately, there are a number of recyclers Weed control is extremely important in con-around the country that accept nursery tainer production. Weeds compete for waterplastic. The Plastics Division of the Amer- and nutrients and hinder sales of nurseryican Chemistry Council Web site, www. stock. Weed control efforts should focus, provides two areas: in the pot and under the pot.a wealth of helpful information on recyclingof plastics. The plastics division also main- Sanitation is the least costly and most effec-tains the United States and Canada Recy- tive method for controlling weeds. To pre-cled Plastic Markets Database with con- vent weed seeds from blowing into pots, atact data for plastic recycling centers on a vegetation-free zone on and surrounding thestate-by-state basis. The Web site is www. production bed is critical. To keep from growing under the pot, place pots onasp?CID=1591&DID=6053. Recyclers that geotextile weed barriers, often called fab-accept agricultural plastics often have cer- ric weed barrier or landscape cloth. Mod-tain restrictions. Recyclers may require ern landscape cloths are durable and canclean sheet plastic, which often means wash- last for 10 to 12 years in full sun. Land-ing plastic before storage. Plastic must also scape cloths do an excellent job of control-be stored indoors properly. Most hard plas- ling weeds and are permeable to water fromtics like plug trays, flats, pots and hanging irrigation and rainfall, so drainage is not abaskets are either No. 6 polystyrene or No. problem. Although the initial cost is high,2 high-density polyethylene. This distinc- the expense can be prorated as an annualtion is important to some recyclers (20). weed control ATTRA Page 9
  10. 10. Hand weeding is costly, but it may be appro- Alternatives to herbicides priate in a small nursery setting. Weeds Fabric weed barrier disks can control weeds must be removed when they are small since in containers. The fabric disks are pre-slit large quantities of media are lost when pull- and fit on top of the pot around the plant ing big weeds out of containers. stem. Barrier disks prevent weeds from Herbicides are widely used in container growing in containers by excluding sunlight nursery production. Growers use a weed- and inhibiting weed germination. The disks free medium to establish nursery plants, are permeable to air and water but prevent but wind, birds and surface irrigation water germination of troublesome container nurs- all deposit weed seeds onto the pot surface. ery weeds like oxalis. The disks also reduce Broadleaf and grassy weeds love to get a evaporation. free ride into a container nursery because growing conditions in a media-rich pot are Tex-R Geodiscs are fabric disks treated with perfect. Pre- and post-emergent herbicides Spin Out. Geodiscs prevent weed growth are commonly used in commercial nursery by excluding light and pruning the roots of production to control these opportunists. weed seeds that land on the fabric. Geodiscs provide effective weed control for up to three In 1991, Monrovia Nursery, with headquar- years and can be moved from pot to pot. For ters in Azusa, Calif., compared hand weeding distributors, contact Texel USA (22). to spraying herbicides and found that a com- bination of the two is the least-costly method Bonnie Appleton, director of the horticul- (21). See Figure 1 below. Monrovia found it ture master’s degree program at Virginia took workers 10 hours of hand weeding per Tech, recently conducted research using acre, performed 10 times a year, to keep the Geodiscs on container-grown willow oaks nursery weed-free without using pre-emergent (23). The Geodiscs suppressed all weeds herbicides. By using a pre-emergent once in completely. Trees grown in the pots with the spring and once in the fall, the workers Geodiscs had higher top dry weights and only needed to perform hand weeding seven root dry weights than trees grown without times a year, spending one hour weeding each any form of weed control and trees sprayed acre. Monrovia paid workers $8 an hour, the with a conventional herbicide. cost of herbicide was $200 per acre per appli- cation and it took two hours to apply. The Bioherbicides Field production section below has more Corn gluten meal, a recently introduced information on weed control. weed control, is a by-product of corn syrup processing. Corn gluten meal is a pre-emer-Figure 1. Courtesy of American Nurseryman (21). Used with permission. gent herbicide applied in early spring. The Weed-Control Options meal works best when applied to the top one-quarter inch of soil and must be reap-Annual Weed-Control Cost Per Acre (in dollars) 900 800 plied every year. Corn gluten meal is 10 percent nitrogen and acts as a slow-release 700 fertilizer for the crop. Corn gluten meal is 600 patented and sold as an herbicide. See the 500 Resources: Suppliers section for corn 400 gluten meal suppliers. Treating a large area 300 can be quite expensive. Wheat gluten meal 200 has many of the same effects as corn gluten 100 meal, but it has not been patented and may be more affordable. 0 0 Applications 2 Applications 4 Applications Recent research revealed that corn glu- Number of Herbicide Applications per Year ten hydrosylate, which is made from corn Herbicide Cost Herbicide Application Labor Cost Hand-Weeding Cost gluten meal, is more effective controllingPage 10 ATTRA Sustainable Small-Scale Nursery Production
  11. 11. weeds than corn gluten meal (24) and can Final Rule, more nursery growers explorebe applied at less than half the rate for fertilizers acceptable in organic production.effective weed control. Iowa State Univer- ATTRA also has several publications on thesity, the patent holder of corn gluten meal topic, including Potting Mixes for Certifiedas a natural herbicide, maintains a list of Organic Production. Unlike synthetic green-licensed suppliers for this product at www. house fertilizers, there is minimal to support the use of organic fertilizers innology_search/cgm_licensees.cfm. See the a nursery mix recipe. Most of the follow-Resources: Suppliers section for informa- ing material will focus on organic fertilizerstion on purchasing corn gluten hydrosylate. for container nursery production. In sus-There are some new environmentally tainable nursery production the emphasis isfriendly contact herbicides that break down eliminating runoff, regardless of if the fer-quickly and provide options for weed con- tilizer source is synthetic or organic. Exces-trol in container nurseries around irriga- sive nitrates and phosphorus are the mosttion risers and perimeter areas and are also common problems in runoff water (25).applicable for general use in field nursery There are four basic ways to fertilize con-production. One class of products is made tainerized plants: incorporate, topdress,from pelargonic acid, a fatty acid found in liquid feed and foliar feed. In a nurseryplants and animals. Available commercial container, fertilizer incorporation in theproducts include Weed Eraser and Scythe. nursery mix combined with liquid feedingThe products are sprayed on weeds and rap- should provide sufficient nutrition.idly lower the weeds’ pH level, weakeningcell walls and killing the weeds within two Several organic fertilizers provide nitro-hours. A second class of products contain gen. Fertilizers include alfalfa meal, bloodacetic acid (vinegar), lemon juice, eugen- meal and cottonseed meal, among others.gol, thyme oil, orange oil and other natural Materials that provide phosphorus includeingredients. Commercially available prod- oak leaves, bone meal and shrimp wastes,ucts include Nature’s Glory, Burnout and among others. Greensand, granite meal andBioganic. The products work as contact her- soybean meal all provide potassium. Table 3bicides and control, with varying degrees of is not exhaustive, but it provides analyses ofsuccess, broadleaf and grassy weeds. Appli- some popular organic and synthetic slow-cation to nursery plants should be avoided release fertilizers.and several applications may be necessary Maintaining adequate levels of nutrients into kill perennial weeds. the container medium is necessary for opti- mum growth of woody ornamentals. TheFertilization levels of soluble nutrients in containers canLarge-scale container nursery production is be significantly reduced after three or foura huge success largely due to advances in irrigations because of limited container vol-media and fertilizer combinations. Favor- ume and frequent application of water. Useable media and fertilizer combinations are slow-release and liquid fertilizing systems toa result of several decades of research col- overcome this problem.laborations between land-grant universi- Organic or synthetic slow-release fertilizersties, commercial nurseries and the fertilizer help cut down levels of nitrates in runoff waterindustry. Commercial synthetic fertilizers (1). Slow-release and controlled-release syn-including slow-release and liquid fertiliz- thetic fertilizers, like commercially availableers play a key role in this picture. Detailed Nitroform and Osmocote, are common in con-information on commercial nursery mixes tainer production systems. Incorporate slow-and fertilizer systems is available through release and controlled-release fertilizers intothe Cooperative Extension Service. the growing media for best results. Do not top-As organic production becomes standard- dress. Slow-release fertilizers are often usedized under the National Organic Program in combination with liquid ATTRA Page 11
  12. 12. Table 3. Analysis of organic and synthetic slow-release fertilizersOrganic fertilizers %N %P %K Other nutrientsBat guano (fresh) 10 3 1 CalciumBat guano (old) 2 8 0 CalciumBlood meal 10 0 0Bone meal (steamed) 1 11 0 CalciumCottonseed meal 6 2 1Eggshells 1.2 0.4 0.1 Calcium and trace mineralsFish emulsion 4 1 1 SulfurFish meal 5 3 3Greensand 0.0 0.0 7.0 32 trace mineralsHoof and horn meal 12 2 0Kelp meal 1.5 0.5 2.5 Trace mineralsManure Cow 2 2.3 2.4 Horse 1.7 0.7 1.8 Pig 2 1.8 1.8 Sheep 4 1.4 3.5 Poultry 4 4 2Oak leaves 0.8 9.4 0.1Pine needles 0.1 0.0 0.5Sawdust, well rotted 0.0 0.2 0.2Soybean meal 7.0 0.5 2.3Worm castings 0.5 0.5 0.3 11 trace mineralsSlow-release synthetic fertilizers Effective periodIBDU 31 0 0Lesco 20 6 12 4-6 monthsMagAmp(also contains 25% 8 40 0 100 daysmagnesium)Osmocote 13-19 6-14 12-14 3-4 or 8-9 monthsPrecise 12 6 6 3-4 monthsPremix (also contains 24 7 8 6-8 weeksmicronutrients)ProKote 20 3 10 7-9 monthsSta-Green 12 6 6 6-8 weeksPage 12 ATTRA Sustainable Small-Scale Nursery Production
  13. 13. Table 4. Materials for organic fertigation*Element Material BenefitsNitrogen Liquefied fish Biostimulant, balanced NPK Liquid manures Rapid uptake Phytamin 800 Rapid uptake, high solubility Sodium nitrate** Rapid Spray-dried fish** Rapid uptake, biostimulantPhosphorus Bat guano** Rapid uptake Micronized rock phosphate** Biostimulants, 16% P2O5 Seabird guano** Rapid uptake, 10% P2O5Potassium Soluble Sul-Po-Mag** Supplies K, Mg, and S Soluble sulfate of potash** 50% K, 18% SN-P-K combination Fish products Liquefied manures Phytamin 3-2-3 Rapid uptake Seabird guano** 12-12-2.5Calcium Solution grade gypsum** Calcium and sulfur Solution grade limestone** 98% CaCO3Sulfur Micronized sulfur** Up to 90% S Solution grade gypsum**Trace mineral/ Compost teas Biostimulant, humic acidsbiostimulants Kelp extract powders** Trace minerals, biostimulant Kelp extract liquids Trace minerals, biostimulant Liquid humates Humic acids, biostimulants Liquid trace minerals Various formulations Micronized compost** Biostimulant, humic acids Micronized humates** Humic acids, biostimulant Rock dusts** Trace minerals, biostimulant *Reprinted with permission from Amigo Cantisano. 2000. Organic growers can fertigate! Growing for Market. March. p. 8-9.**Dry material: Must be premixed and thoroughly agitated in water prior to and during injection. May be less soluble than liquid formulations.Nitrogen is the main nutrient supplied do not clog drip emitters and microsprin-through liquid feeding, or fertigation. klers (26). Fish protein, blood protein,Organic liquid fertilizers include fish emul- poultry protein and brewers yeast are allsion, fi sh powder, blood meal, bat guano, available as spray-dried materials. Amigoseabird guano, worm castings and compos- Cantisano, an organic agriculture con-ted manure teas. Some forms of organic fer- sultant in California, compiled Table 4tilizers are more adaptable to low-volume (27).irrigation systems like drip or trickle sys-tems. A 1992 study found that spray-dried Foliar feeding can supplement soil and liq-fi sh protein and poultry protein fertilizers uid fertilization, especially where ATTRA Page 13
  14. 14. nutrients are deficient and must be incor- porated into the plant quickly. Use fi ltered Chris Starbuck, extension specialist at the solutions of manure, seaweed, fish powder University of Missouri, developed the Mis- and fish emulsion. Seaweed is an excellent souri Gravel Bed as an alternative growing system for nursery stock (29). The gravel foliar material because it contains growth bed uses a mixture of gravel and sand to get hormones, including auxins, gibberellins young plants established. The gravel bed is and cytokinins, as well as trace elements. inexpensive because it uses neither contain- Research suggests that foliar feeding pro- ers nor potting mix, but produces healthy grams enhance plant resistance to pest and bare-root plants. disease attack. Compost teas are popular as The gravel bed uses half-inch or smaller a foliar feed primarily because of their dis- gravel mixed with 10 to 15 percent sand ease-suppressive characteristics. and is 14 to 18 inches deep to support 1.5- inch caliper trees. Starbuck places dormant, For more information on alternative fertil- bare-root plants in the bed in early spring. izers, request the ATTRA publication Alter- He applies slow-release fertilizers on top of native Soil Amendments and the Web-only the gravel. Starbuck leaves plants in the bed database Sources of Organic Fertilizers and for at least six weeks, but pulls the plants the Amendments. Another useful resource is year they are planted. He uses an automatic Fertile Soil by Robert Parnes (28), an in- trickle irrigation system. depth publication on organic fertilizers. Starbuck helped growers in more than 40 Parnes’ publication provides detailed tables states establish gravel beds for their opera- on the nutrient content of various manures tions. A grower in Iowa successfully overwin- and plant and animal by-products. tered plants in temperatures as low as minus 25 degrees Fahrenheit. The roots are as pro- tected in gravel as they would be in soil and Potting media are more protected than they would be in Field soil is sometimes used in container containers. mixes. Field soil makes up 10 to 30 percent of the mix by volume, but soil is heavy and requires the additional step of pasteuriza- Mycorrhizae are soil fungi that form benefi- tion to eliminate diseases and weed seeds. cial associations with plant roots. Mycorrhi- The standard replacement for soil is peat zae enable plant roots to do a better job of moss, but there is concern that peat is a gaining nutrients and water. The fungi can non-renewable resource. Research is being be used in field or container production. conducted to determine what materials can Growers achieve better stand establishment, be used to replace peat. Most of the prod- use less fertilizer and inoculate bare-root ucts being tested are some form of waste. seedlings when using mycorrhizae. Com- mercially available mycorrhizae stimulate Composted pine bark, a by-product of the the roots of almost all tree and shrub spe- lumber industry, is an excellent medium cies. For a listing of suppliers of mycorrhi- for containerized plants. Mixes containing zae, see ATTRA’s Sources of Organic Fertil- more than 20 percent composted pine bark izers and Amendments. support a significant level of suppression of Pythium damping-off (30). Other alter- natives are coir, spent mushroom compost, Field production paper mill sludge, apple pomace, shredded Until the 1950s, virtually all nursery pro- newspaper, compost, processed alfalfa, pro- duction occurred in the field. Field produc- cessed kenaf, recycled cardboard and com- tion is still widely used to produce bare-root posted municipal yard waste. Most studies seedlings for conservation plantings, fruit show that these alternative products should trees and nursery liners. The most profit- not compose more than 50 percent of the able product of field nurseries is bagged mix. For in-depth information on these top- and burlapped shade trees for the land- ics, ask for the ATTRA publication Potting scape industry. In-ground production is Mixes for Certified Organic Production. advantageous to tap-rooted tree species,Page 14 ATTRA Sustainable Small-Scale Nursery Production
  15. 15. mass plantings, inexpensive establishment The advantages of field grow bags areand large caliper (trunk diameter) size. Dis- numerous. Bags enhance rooting, leave 80advantages of in-ground production include percent of roots intact during transplant-a higher percentage of plant loss and longer ing, make harvesting easier, save labor andestablishment periods after transplanting. time, do not require special machinery at harvest and can be harvested year-round.Field nursery production involves the use Bagged and burlapped plants are normallyof unique soil management practices. Soil- harvested only during dormancy (31).building cover crops and crop rotations areimportant to maintain good soil structure, There are also disadvantages. The initialfertility and organic matter. Living mulches investment in grow bags is expensive, plantsare cover crops planted in the aisles to hold need more staking and water after trans-the soil, provide traction, increase water planting, damaged bags cannot be used,infi ltration and suppress weeds. Legume mechanical cultivation and precise fertilizercover crops fi x nitrogen and can be used application are difficult and bag removal canto reduce the amount of nitrogen fertilizer be difficult and time consuming (31).applied each year. See ATTRA’s Overview The greatest disadvantage of growing in Iof Cover Crops and Green Manures for fur- bags is marketing the plants. Few people ntegratingther information and resources. know the advantages of growing in bags and living mulches,Integrating living mulches, cover crops and find bagged trees less convenient to handle cover crops andthe application of high-quality composts in than containerized trees. One way around this is to grow the plant in a pot for the last the application offield nursery operations are the fastest waysto improve nursery soil. To reduce pest year of production. high-qualityproblems, plant a diversity of species rather composts in field An important consideration in bagged andthan a large block of single species followed burlapped production is the loss of 200 to nursery operationsby a large block of another species. Habitat 250 tons of topsoil per acre at each har- are the fastest ways tomanagement for beneficial insects is also an vest. The digging and removal of topsoil improve nursery soil.option in a field situation. For more infor- from bagged and burlapped nursery oper-mation on this, see ATTRA’s Farmscaping ations is a practice that can, over a longto Enhance Biological Control. time, seriously deplete the farm’s mostNursery equipment and irrigation systems important resource. There are two ways tofor field nursery production are unique. fight topsoil depletion. Replace topsoil withSuppliers are listed in the trade publication something else or have a bare-root opera-Nursery Management and Production Buyer’s tion that does not require topsoil to leaveGuide and in the magazine American Nurs- the farm. Many growers use compost toeryman. See the Resources: Publications replace some of the topsoil that is lost, butsection for contact information. applying more than 40 tons of compost per acre is not recommended.A recent innovation in field nurseryproduct ion is the use of in-g round Weed controlfabric containers, sometimes called rootcontrol bags or field grow bags. Dr. Carl Weed control in modern field nursery pro- duction is based on the use of herbicides.Whitcomb, formerly head of the nurs- There are many excellent non-chemical alter-ery research program at Oklahoma State natives, however. These include mechanicalUniversity, developed these containers in cultivation, flame weeding, mulches, livingthe early 1980s. The bags have a fabric mulches, steam and solarization.or clear polyethylene bottom stitched orglued to walls made of non-woven fabricand come in several sizes (31). In theory, Mechanical cultivationthe bags combine the best qualities of Bärtschi-Fobro (32), a Swiss manufacturercontainer and field production. of nursery equipment, offers ATTRA Page 15
  16. 16. implements including a brush hoe for preci- inches wide, from 1/2 inch to 10 inches sion weeding in multiple-row seedling nurs- deep. ery beds. The company also makes brush Landscape fabric can also be used in field heads that disturb the soil surface and dis- production. A fast way for growers to get lodge weed seedlings as the drum turns. into production is to lay cloth in the field, The company no longer has a U.S. distribu- cut or burn holes in the cloth and then plant tor, but small-scale implements may still be the liners or seedlings. available through used-equipment dealers. Researchers at Oregon State University Flame weeding found that mulches made of oyster shell, hazelnut shell and copper-treated geotex- Flame torches, or flamers, may be an option tiles provide good suppression of liverwort, in some nursery situations. Flaming works a prevalent weed in many nurseries. These by searing and disrupting plant cells, not three mulches outperformed mulches of by burning plant tissue. Passing a flamer rockwool, peat moss, coarse sand, perlite, quickly over a weed is enough to kill the top pumice and the commercial herbicide Ron- of the weeds, but roots can re-sprout new starand Surflan. The mulches also outper-F lame weeders growth. Broadleaf weeds are more suscep- formed iron oxide, copper sulfate and man- can be used tible to flaming than grassy weeds. Flam- ganese sulfate fertilizers (35). ing needs to be repeated every two to three to prepare weeks to control grasses.a stale seedbed by Living mulchesflaming off the first Flame weeders can be used to prepare a In a 1990s study conducted in Minnesota, stale seedbed by flaming off the fi rst and researchers compared soil cultivation, her-and second flushes second flushes of weeds to emerge after bicides and three living mulches for weedof weeds to emerge seedbed preparation. Weed fl amers can suppression in a field with six species ofafter seedbed also control post-emergent weeds. To pro- ornamental trees (36). The researcherspreparation. tect young seedlings from injury, use flam- used Norcen bird’s-foot trefoil, Wheeler ing shields. Taller seedlings and trees with winter rye and a grass sod consisting of well-developed bark can withstand directed 80 percent Eton perennial ryegrass and fl aming aimed at weeds growing in and 20 percent Ruby red fescue. The grass sod between the rows. Although there is some provided excellent weed control, but was criticism that flaming is not a sustainable overly competitive with the trees. The tre- practice because it uses fossil fuels, flame- foil was infested with weeds. The winter killing a nursery bed or field of seedlings rye, which was killed with herbicides and uses less fossil fuel than manufacturing, then acted as a mulch, provided good weed transporting and spraying an herbicide for control and increased water infi ltration and the same job (33). For more information soil moisture. That evened out soil tempera- on flaming, contact ATTRA at 1-800-346- ture fluctuations, reduced soil bulk density, 9140 or improved nutrient cycling and reduced field maintenance costs. In general, the cover Mulches crops tended to reduce annual weeds and Mulches are another way to exclude weeds. favor perennial species. Mulches keep out weeds by limiting light and retaining moisture in the soil. Organic Steam mulches should be 3 to 4 inches thick and For years, conventional production systems need replenishing once or twice a year. used methyl bromide to sterilize soil before Millcreek Manufacturing, based in Leola, planting. One sustainable system that yields Pa., offers a row mulching machine that the same results uses steam to disinfest can apply mulch and compost to field- beds and greenhouses prior to planting. In grown stock (34). The machine costs about a field planting, this system can treat plant- $5,000 and can mulch beds from 18 to 48 ing beds. Steam is nontoxic, easy to apply,Page 16 ATTRA Sustainable Small-Scale Nursery Production
  17. 17. Table 5. Organic mulchesType Source of weeds CommentsGrass clippings Yes Usually free, not very attractive Inexpensive, very effective, not very attractive, canNewspaper No attract slugs Very expensive, decomposes in 2-3 years, adds highCocoa hulls No amounts of potassiumCottonseed hulls No Expensive, not available everywhere Decomposes in 2-6 years, chunks are bulky and canPine bark nuggets No wash awayShredded softwoods (cedar, No Price depends on local availability, attractive, decom-cypress, etc.) poses in 2-5 years Can be quite inexpensive if obtained from chippedHardwood chips No shrubs or trees, decomposes in 1-3 yearsCompost No Available, attractiveCorn stalks No Not available everywhere, unattractiveWheat straw Yes Inexpensive, decomposes rapidlyHay Yes Inexpensive, decomposes rapidlyRice hulls Yes Not available everywherePine straw Yes Inexpensive, attractive, decomposes in 1-2 yearsLeaves Yes Usually free, compost firstCardboard No Inexpensive, lasts a long time Inexpensive, depletes nitrogen, can blow away, betterSawdust No to use aged materialcontrols the same soil pests as conventional Solarizationmethods and works in a wide variety of cli- Soil solarization is another option for kill-mates and conditions (37). ing pests before planting trees, shrubs orA small portable boiler is the best unit to perennials. Treat only beds that will beuse for a greenhouse. The Sioux Steam planted. The basic principle of solarizationFlo, available from the Sioux Corporation, involves stretching sheets of clear plasticwill work for greenhouse operations and across moist ground. Solar radiation heatscosts about $5,700. For small beds in the the soil and kills pests, including weedfield, larger units are available from Saska- seeds and harmful insects. Solarizationtoon Boiler Manufacturing in Canada. See can kill annual and perennial weeds ifResources: Suppliers for contact infor- summer temperatures climb high enough.mation. The important differences in steammachines are how much heat the machines Solarization can also be used to disinfestput out, how portable the machines are reused or soil-based potting media. Toand how far into the soil the steam pen- do this, enclose the media in plastic bagsetrates. Although most machines heat only and leave them in the sun for two to threethe top 3 to 6 inches of soil, temperatures weeks. Two layers of plastic kill moreare high enough to kill most weed seeds. pests and work about four times fasterMachines that heat the soil to 140 degrees than one layer (38). For more informationfor at least 30 minutes kill pest fungi, on soil solarization, contact ATTRA atbacteria, nematodes and weed seeds. 1-800-346-9140 or ATTRA Page 17
  18. 18. Harvest and storage • Prices and quantities offered by competitors At some point, nurseries must dig up field- grown trees and plants. See the Resources: • Supply and demand for the crop, Suppliers section for manufacturers of tree except prices for high-quality prod- diggers. Plants are often stored after dig- ucts and loyal customers (1) ging. Conventional production systems dig The British Columbia Ministry of Agricul- trees in late fall or early winter and store ture, Fisheries and Food compiled a Plan- trees in warehouses until early spring. Dur- ning for Profit series of online publications ing this time, nurseries spray bare-root that details costs involved in establishing trees with fungicides and bacteriostats to and growing several nursery species. These keep problems from arising. enterprise budgets provide information on expenses and income for perennial and tree Researchers in Rhode Island experimented crops grown in containers and in the field. with Taxus bagged and burlapped stock to The guides provide a rough idea of how prevent the plants from rooting out, a con- much it costs to start production and how dition where the roots grow into the burlap long it takes to make a profit. See the minis-O bags. They used Spin Out, an EPA-approved try’s Web site at ne way copper paint, in several different ways (39). budgets/index.htm for more information. to cut Treatments included painting the bottom produc- of the root ball with copper paint, setting For costs associated with establishing a the root ball on copper-treated burlap and small perennial nursery, see the handbooktion costs is to grow rewrapping the root ball with copper-treated Requirements and Costs of Establishing andplants in smaller Operating a Three-Acre Herbaceous Perennial burlap before mulching. Although all thesecontainers. treatments provided good control of rooting Container Nursery listed in the Resources: out after 12 to 16 weeks, the most effec- Perennials section. See Betrock Informa- tive treatments were setting the root ball tion System’s Web site for a on copper-treated burlap and leaving it list of horticultural software that focuses on plant selection and nursery management. unmulched. The researchers also found that placing the root balls on TexR Agroliner, a Competitive prices can fall below the cost Spin Out-treated non-woven fabric, stopped of production. In this circumstance, a nurs- rooting out completely. ery with a unique advantage, like proximity to its market or a superior product, may be Costs able to maintain a higher price that covers costs without experiencing a serious drop in The costs of nursery production include the number of plants sold. overhead, direct and marketing costs. Over- head costs include all the general costs of Although it is desirable to make a profit on operating the nursery, like taxes, depre- each kind of plant, sometimes it is good ciation, interest, rent, utilities, insurance, marketing strategy to grow some plants maintenance and repair, new construction, that may not be profitable in order to offer new equipment, supplies, managerial and a well-rounded inventory. A small nurs- administrative salaries and labor wages that ery might specialize in a few high-quality cannot be assigned to a particular crop. plants or produce some plants not carried Direct costs are tied to a crop, like pur- by larger nurseries, which produce only chasing seed, potting media and fertilizers. plants with high sales volumes. Keeping excellent records is the best way to One way to cut production costs is to grow accurately determine true costs. plants in smaller containers. Although the Prices should reflect: crop sells for less, the costs of media and containers are reduced, as well as the time • Exact production costs that include needed to produce the crop. Selling plants at a reasonable profit for each crop wholesale prices means less money receivedPage 18 ATTRA Sustainable Small-Scale Nursery Production