Organic Greenhouse Vegetable Production


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Organic Greenhouse Vegetable Production

  1. 1. 800-346-9140 ORGANIC GREENHOUSE VEGETABLE PRODUCTION HORTICULTURE SYSTEMS GUIDEAppr i e Technol Tr opr at ogy ansf f Rur Ar er or al eas ATTRA is the national sustainable agriculture information center funded by the USDA’s Rural Business -- Cooperative Service. Abstract: Organic greenhouse vegetable production is regularly practiced by certified organic farmers and market gardeners, and has potential for wider adaptation by established greenhouse operators and entry level growers as a niche market or sustainable method of production. This publication focuses on organic methods of greenhouse vegetable production, and it is supplemented with a listing of greenhouse resources.By Lane Greer and Steve DiverNCAT Agriculture SpecialistsJanuary, 2000IntroductionAlthough several Extension bulletins areavailable on greenhouse vegetable production,few of these concentrate on organic productionmethods. This publication presents an overviewof greenhouse production systems and profilesseveral farmers raising organic vegetables ingreenhouses. It is hoped this will give newgrowers ideas of how to set up their systems,and provide more experienced farmers withexamples of alternative methods of production.The term greenhouse means different things todifferent people. A greenhouse used to be astructure formed of glass, with a heating (andusually cooling) system that was used year- round, but especially in winter. Then came Index houses built of thermoplastic (Plexiglas and Introduction//Page 1 others), followed by Quonsets covered with The Greenhouse Vegetable Industry//Page 2 plastic, which may or may not be heated, have How Can Small Growers Compete?//Page 2 Organic Greenhouse Production//Page 4 one or two layers, and be used year-round or for Soil vs. Soilless Culture//Page 7 only a few months every year. The type of Soil Culture//Page 8 greenhouse you have will largely be determined Soilless Culture//Page 10 by your crop and your capital and, to a lesser Hydroponics//Page 12 extent, by your management intensity and your Variety Selection//Page 13 market strategy. Economics//Page 13 Developments in the Greenhouse Industry//Page 14 For the purposes of this publication, a Summary//Page 15 greenhouse can be any of the above. Another References//Page 15 ATTRA publication, Season Extension Techniques Seed Sources/Page 16 for Market Gardeners, contains further Organic Fertilizer Suppliers//Page 16 information on protected shelter structures such Resources//Page 16 as cold frames, high tunnels or “hoophouses,” and low tunnels. ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 1
  2. 2. The Greenhouse Vegetable Industry The leading states in greenhouse vegetable production are California, Florida, Colorado, Small-scale growers who plan on direct Arizona, Ohio, Texas, and Pennsylvania—all market sales may want to think twice with over one million square feet of production before getting into this business in a each (2). This is where the centers of region that is already saturated. production exist, both as a source of competition as well as a source of technical assistance. Small-scale growers who plan on direct marketThe U.S. greenhouse vegetable industry is a sales may want to think twice before gettingmixture of small, family-run operations in the into this business in a region that is already2,500 to 10,000 square foot range and a small saturated.number of large, multi-acre facilities 10 acres ormore in size. The larger greenhouses often use How Can Small Producers Compete?waste heat from a power plant or other sourceof cogeneration (1). With so much competition from Canada, Mexico, and overseas, how can small farmersCurrent U.S. production estimates are realize a profit raising greenhouse vegetables?somewhere around 800 acres (2). In One issue of increasing importance tocomparison, Mexico has about 450 acres, consumers is vegetables grown with minimumCanada has about 1,600 acres, and Holland has pesticides. The public has also become educatedover 11,000 acres (3, 4). In the latter part of the on the values of locally grown produce: it’s1990s, Canadian greenhouse vegetable fresher, it tastes better, and it may even be lessproduction grew at a rate of 20% a year. How expensive, since there are fewer shipping costshas Canada been able to generate this huge involved. Also, money paid to a local farmer isgrowth? “Significant new greenhouse vegetable re-invested in the local community and helps toproduction technology that was transferred to keep that economy strong.commercial producers has been primarilyresponsible for dramatic yield increases over the Year-round production is key to maintaining thelast 7–8 years, estimated at 100–120% for greenhouse’s profitability. However, this doestomatoes and 70–80% for cucumbers” (3). not necessarily mean that growers should beCanada is strongly supporting its greenhouse producing the same crop year-round. (Wintergrowers, both with research and with tomatoes bring more money than do summerinvestment dollars. Their research facilities at ones.) Another option would be to raise a cropHarrow are recognized as topnotch the world other than vegetables, like bedding plants forover. Although most Canadian greenhouse early spring sales or poinsettias for Christmas.vegetables are not produced organically, there The grower may decide that the most cost-has been an emphasis of late to use IPM efficient way to use his or her greenhousestrategies, rather than pesticides, to during the summer is to shut it up to solarizeaccommodate the growing market of consumers the soil and “cook” insects (and their eggs) thatwho want pesticide-free produce. Most of the are produce imported into the U.S. is nowcoming from Mexico. Small growers must find niche markets. It is pointless to try to compete with massTomatoes are the leading greenhouse vegetable merchandisers like Wal-Mart, because the smallcrop, followed by European cucumbers, lettuce, grower will always lose. What are some nichepeppers, and culinary herbs such as basil, sage, markets for organic greenhouse vegetableand rosemary. See the ATTRA publications on producers? Some of the general niches havethese specific vegetables for more information. already been mentioned: consumers are lookingIn addition, growers aiming at niche markets for organic, locally grown, early-seasonraise specialty crops, greens, and Oriental produce. Whatever the niche market, it isvegetables. important for growers to realize that the nature ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 2
  3. 3. of niche markets is for them to disappear after a help growers identify some of the best resourceswhile. Oversupply or lowered demand will on this topic, ATTRA compiled the Solarcreate lower prices. The market will change to Greenhouses Resource List.favor one product and disfavor another. Thismay happen when mass merchandisers enter One recent publication that features organicthe market, when the popular press promotes a vegetable production in a solar greenhouse isparticular vegetable, or when new medical Anna Edey’s book Solviva: How to Grow $500,000evidence points to increased or decreased health on One Acre and Peace on Earth. Solviva is Edey’sbenefits from certain vegetables. award-winning solar-powered and animal- heated greenhouse on Martha’s Vineyard. TheA good example of changes in a niche market is book discusses greenhouse design, function,the salad greens industry. Fifteen years ago, leaf construction, and management. Ms. Edeylettuce was almost impossible to find. When includes numerous energy-efficient designs likeleaf lettuces were introduced to the general water walls and growtubes. She also tells howpublic, few people accepted them. When chefs much everything costs, which is invaluable forin finer restaurants began using them, more market gardeners. Solviva is available for $38affluent people began asking for them in from:markets. The undersupply led to extremelyhigh prices; as much as $16 per pound was not GFM Booksuncommon. More and more small growers PO Box 3747began producing salad greens, but it wasn’t Lawrence, KS 66046until large growers entered the market that the 800-307-8949price per pound went down significantly (to $6–10 a pound). Many growers can still get $4–6 a Composting Greenhousespound for greens, but as more large growersenter the market, this price will continue to Heating greenhouses with waste heat generateddrop. Long before the market has bottomed out by compost is a second option that takesis when small growers need to diversify and advantage of local resources and integratesfind ways to add value to their crops, like different farm activities. In a compostingoffering pre-cut, washed and ready-to-eat mixed greenhouse, heat and carbon dioxide arelettuces. generated from manure-based compost contained in a special chamber attached to oneLabor and energy are usually the two greatest side of the greenhouse.greenhouse expenses. If small growers can finda way to decrease costs of either or both of Compost-heated greenhouses gained a lot ofthese, their chances of making a profit are attention from work undertaken at The Newstrengthened. How can they do this? Cheap Alchemy Institute at Falmouth,sources of energy are key. Sunlight, Massachusetts. The New Alchemy Institutedecomposing compost, and animal heat are was one of the premier appropriatethree ways to decrease energy costs. technology centers that operated in the 1970s and 80s. The Institute published widely onSolar Greenhouses ecology, wind energy, solar energy, bioshelters, solar greenhouses, integrated pestGreenhouses can be designed to take advantage management in greenhouses, organicof solar radiation and cut fuel expenses. Solar farming, and sustainable agriculture.greenhouses are popular with small-scalegrowers. These are super-insulated Though the technology to implementgreenhouses designed to collect and retain solar compost-heated greenhouses exists, they areenergy. The technology associated with solar seldom done on a commercial scale. ATTRAgreenhouses is rather detailed. In addition, the can provide more information on this topic onliterature on solar greenhouses is quite large. To request. ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 3
  4. 4. In 1996, there was a SARE-funded project Related publications from ATTRA include: headed by Rick Meisterheim in Michigan titled “Permaculture Greenhouse System.” He raised • Hydroponic Vegetable Production chickens in the greenhouse and found that they • Aquaponics: The Integration of raised the overall temperatures inside the Hydroponics with Aquaculture greenhouse by an average of 8°F. This proved • Solar Greenhouses Resource List to be very helpful in raising vegetable • Organic Potting Mixes transplants. Rick was able to set out seedlings • Disease Suppressive Potting Mixes much earlier than other years, thus increasing • Sources of Organic Fertilizers and the length of time his CSA generated income (5). Amendments • Season Extension Techniques for Market Again, bio-heated greenhouses hold interest Gardeners among small-scale growers who are focused on • Integrated Pest Management for bio-integrated systems as a form of energy Greenhouse Crops efficiency and biomass utilization. Of the three • Greenhouse IPM: Sustainable Aphid greenhouse-heating methods summarized here, Control solar greenhouses have the least risk and hold • Greenhouse IPM: Sustainable Thrips the most promise for commercial-scale ventures. Control Nevertheless, for those individuals seeking • Greenhouse IPM: Sustainable Whitefly information on bio-heated greenhouses, ATTRA Control can supply more information on request. • Compost Teas for Plant Disease Control • Use of Baking Soda as a Fungicide Organic Greenhouse Production • Organic Greenhouse Tomato Production As defined by the USDA in 1980 (6), organic • Organic Greenhouse Pepper Production farming is a system that excludes the use of • Organic Greenhouse Cucumber Production synthetic fertilizers, pesticides, and growth • Organic Greenhouse Lettuce Production regulators. Organic farmers rely heavily on • Organic Greenhouse Herb Production crop rotations, crop residues, animal manures, • Organic Plug and Transplant Production legumes, green manures, organic wastes, and mineral-bearing rocks to feed the soil and supply plant nutrients. Insects, weeds, andAnimal-Heated Greenhouses other pests are managed by mechanical cultivation, and cultural, biological andSmall animals like chickens and rabbits produce biorational controls.heat and carbon dioxide in addition to productslike eggs and meat. A few growers have takenadvantage of this fact and integrate animals No single fertilizer will provide all of thewith greenhouses as a source of heat. However, essential elements required, but ait can be a challenge to keep livestock in a combination of organic products can begreenhouse—the higher temperature and devised.humidity of a greenhouse are generally nothealthy for animals. Organic certification emerged as a marketingAnna Edey, mentioned above, uses an “earth- tool during the 1970s and 80s to ensure foodslung” to filter out the toxic ammonia gas from produced organically met specified standards ofthe rabbit and chicken manure she uses in her production. The Organic Foods Production Act,Solviva greenhouse. In addition, she keeps her a section of the 1990 Farm Bill, enabled thechickens in a poultry room attached to the USDA to develop a national program ofgreenhouse where temperatures do not fluctuate universal standards, certification accreditation,from about 70°F. and food labeling. Early in 1998, the USDA ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 4
  5. 5. released a draft of the new standards for public Fertilitycomment. Public opposition to these proposedstandards was vocal, sending a message to the Although the process is more complicated, it isUSDA that more work was necessary. A new possible to obtain adequate nutrients fromdraft of organic standards may be released in organic sources, but it takes more careful and2000. In the meantime, organic certification will creative management. No single fertilizer willcontinue to occur at the state level for most of provide all of the essential elements required,the country. For more information on these but a combination of organic products can beorganizations, ask for ATTRA’s Organic devised.Certifiers resource list and Organic Certificationpublication. Organic fertilizers have not been well researched in greenhouse vegetable production.Growers may choose organic methods for a However, a 1999 study performed at thevariety of reasons. One of the attractions of University of Kentucky analyzed severalgrowing organic produce is that it sometimes products for the levels of nutrients theybrings a 10–30% premium in the marketplace. supplied. The researchers were attempting toAs organically grown produce becomes more prove that organic fertilizers could supplycommonplace, however, premiums may be the nutrients at the same level as syntheticexception rather than the rule, and motivation fertilizers. Products derived from algaebeyond market premiums should be considered. (Algamin, a liquid, and Maxicrop, a powder),These may include the possibility of reduced bat guano, and fish waste (GreenAll Fishinput costs, improved farm safety, reduced Emulsion, a liquid, and Mermaid’s Fishenvironmental impact, and a better functioning Powder) demonstrated nutrient levelsagroecosystem. comparable to conventional, synthetic fertilizers used for greenhouse plant production (7). TheGreenhouse technology and horticultural report concluded that these organic fertilizerspractices differ little between conventional and could not be used as a concentrate for injectororganic greenhouse production. The main systems, but they would be suitable in avariations are concerned with pest control and capillary mat subirrigation system. Forfertility. The ATTRA publication Integrated Pest information on how to obtain these products,Management for Greenhouse Crops examines the see the Resources section.first issue; the second issue is addressed in thefollowing sections. In 1993, Premier Peat Moss in Canada conducted research on organic wastes from the Fertilizer N-P-K Shoot wt. (grams) Crab-shell meal 8.2-1.5-0.5 18.8 Blood meal 12.5-1.1-1.0 18.5 Dried whey sludge 5.3-2.5-0.9 18.3 Feather meal 13.6-0.3-0.2 17.3 Fish meal 10.1-4.5-0.5 17.1 Meat meal 7.7-3.1-0.7 16.3 Cottonseed meal 6.5-1.1-1.6 16.2 Fish-scale meal 10.0-3.7-0.1 15.8 Distiller’s dried grains 4.3-0.9-1.1 14.5 Soybean meal 7.5-0.7-2.4 14.4 Wheat bran 2.9-1.4-1.3 13.5 Alfalfa meal 2.5-0.3-1.9 10.8 Canola meal 6.0-1.1-1.3 10.8 None (control) 0-0-0 10.3 ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 5
  6. 6. agri-food industry and their ability to fertilize during the growing season such as fruit filling.greenhouse tomato transplants (8). The However, fertigation is not a substitute for aresearchers found that meal from blood, complete soil-based fertility program.feathers, meat, crab shells, fish, cottonseed andwhey by-products increased shoot weight by The injection of organic fertilizers into low-volume57–83% over non-fertilized plants. The results irrigation systems like drip emitter and micro-of their study are shown on page 5. sprinkler is non-conventional, because the standard method relies on commercial synthetic fertilizersLiquid fertilizer applied through irrigation that are highly soluble in water. The major concernlines—a technique known as fertigation—is a with organics is clogging of emitters and pores withcommon practice in greenhouse production. particulate matter and algae.Nitrogen and phosphorus are the two primarynutrients injected through fertigation systems. In the early 1990s, researchers in CaliforniaFertigation can provide supplemental doses of concluded that fertigation with certain organicthese nutrients, especially at critical periods fertilizers is feasible (9). Spray-dried fish and Organic Strategies for Nutrient Deficiencies* Element Deficiency Symptoms Remedy Nitrogen (N) Old leaves turn pale green then yellow with Dried blood, fish meal, or guano reddish veins and midribs. Stunted growth. extracted in water. Add greater amounts in your next compost batch. Phosphorus (P) Stunted growth, dull green leaves with purple Add reactive rock phosphate or tints. Old leaves scorch at the edges and extract of guano in solution. Add wither early. Early, premature bolting. greater amounts of guano, bone meal, or fish meal to the next compost batch. Potassium (K) Small, dark, bluish-green, glossy leaves, Add more kelp extract to the curving slightly backwards. Old leaves with nutrient solution. Add greater yellow patches, scorched edges cured amounts of ashes to the next upwards. Small root system. compost batch. Calcium (Ca) Young leaves cupped backwards, with white Add lime in solution. Add greater spots around the edges. These later turn proportions of bone meal, brown. Forward rolling of the leaf margin. gypsum, or dolomite to the next compost batch. Element Deficiency Symptoms Remedy Magnesium (Mg) Leaves become bronzed, and later, yellow Dolomite or serpentine in patches appear between the leaf veins. solution. Add greater amounts of dolomite and animal manures to the next compost batch. Sulfur (S) Purpling of old leaves, which then shrivel. Sulfur in solution. Greater Young leaves small and yellow between the proportions of gypsum and veins. poultry manure required in the next compost batch. Manganese (Mn) Veins stand out clearly with yellow in Add extra kelp extract. between. As the plant ages, small dead spots and papery areas appear. Slow root growth. Boron (B) Split or thin misshapen roots. Roots with torn Add extra kelp extract. patchy surface and dull skin. Iron (Fe) Very pale leaves, especially the youngest early Add more kelp extract or place in the season. Veins stay dark. some rusty nails in the bottom of the nutrient tank. *Reprinted with permission from: Morgan, Lynette. 1997. Organic fertilizers for hydroponics. The Growing Edge. November-December. p. 32-35, 37-39. ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 6
  7. 7. poultry protein fertilizers were injected through In an excellent article on organic fertilizers forvarious drip, drip-tape, and micro-sprinkler hydroponic systems, Dr. Lynette Morganirrigation systems, with even distribution and suggests remedies for nutrient deficiencies. Theminimal clogging. The protein products are table on page 6 is excerpted from her article (10).easy to use because they are finely ground andsold dry. The N-P-K analysis for both fish and James Baker raises organic cucumbers, tomatoes,poultry protein is 14-0.5-0.7. At the time of the chives, and squash in Israel. He applies 20–25study, the material cost $1.60/lb., or $12/lb. of cubic meters (706 to 882 cubic feet) of compostnitrogen. In comparison, sodium nitrate costs per quarter acre in the first year of production,about $2/lb. of nitrogen. For product then 10 to 15 cubic meters (353 to 530 cubic feet)information on spray-dried protein fertilizers, on following crops. In addition, he uses feathersee the Resources section. meal for nitrogen, basalt rock for iron and trace elements, and applies bat guano through hisNeptune’s Harvest®, with fish, seaweed, and irrigation system. Says Baker, “I’d prefer to usefish-seaweed blends, is a product line that is poultry manure, but that’s not strictly organicpopular with organic growers using drip because the chickens are fed antibiotics andsystems. (For more information on Neptune’s hormones, and aren’t fed organic grain” (11).Harvest, see the Resources section.) DavidHertzell, an organic greenhouse tomato grower Soil vs. Soilless Culturein Kansas, applies Neptune’s Harvest through Greenhouse production is based on either soil orhis drip-tape system at 32-oz./400 gallons water soilless culture. In soil culture, vegetables areevery ten days. He and other growers prefer the produced in the native soil or in a loamy soilblended mix to straight seaweed, because they brought inside the greenhouse. Soilless culture,feel the nutrient ratios of trace elements are not the production of plants in a soilless medium,as balanced in seaweed alone. David also uses can be done via hydroponics or with an organicrock phosphate at 10 lbs/85’ row, as well as (or artificial) substrate.blood meal, bone meal, and alfalfa meal. Heuses alfalfa mulch, a heavy application of leaf- The two broad categories of soilless culture aremold compost, and cover crops. He also illustrated in the diagram below, with examplessolarizes his soil every five years. of media used in each. Soilless Culture Organic Substrates HydroponicsVertical Towers Straw Bale Shallow Bed Bag Culture Aggregate Liquid Aquaponics Bioponics Inert Organic Mixed Nutrient Film Technique Perlite Peat Peat-Perlite Aeroponics Sand Sawdust Peat-Bark-Sand Floating Raft Gravel Bark Peat-Vermiculite Noncirculating Rockwood Rice Hulls Clay Granules ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 7
  8. 8. In 1974, 70 percent of U.S. production was based applied 5–6 times per growing season at 5–6on soil culture and 30 percent on soilless culture. week intervals. In years two through four theBy 1988, a significant shift to soilless systems compost is applied at a lower rate. Followinghad occurred, with soil systems making up only compost application, the beds are covered with40 percent of the acreage (12). The majority of straw mulch. Soil organic matter in theselarge producers in Canada raise tomatoes, greenhouses ranges from 10–12% up to 25–30%.cucumbers, and peppers in rockwool, andlettuce is usually raised with a nutrient film In contrast, the Luebkes, one of the best knowntechnique (NFT) system (3). Bag culture is often organic farming families in Austria, fertilizepracticed in the U.S., however. The chief greenhouse tomatoes at a rate of 8reasons soilless culture became so popular are: tons/acre/year (13). However, they usea) the elimination of fumigation and steam Controlled Microbial Compost™—a hightreatments for soil-borne diseases; b) ease of quality, microbially inoculated compostinstallation; c) technical assistance available for prepared under aerobic (oxygen-present)soilless systems; and d) fertility control through conditions. In addition to compost, greencommercial soluble fertilizers. manures are an integral part of the Luebke soil management program. After the green manureFive greenhouse production methods suitable is mowed but prior to plowdown, the greenfor organic production are covered in the residue is sprayed with a microbial inoculant tofollowing material: soil culture, bag culture, speed decomposition and enhance humusvertical towers, straw bale culture and shallow formation. Soils treated in this manner havebed culture. Although an overview of tested at 15% organic matter. More informationhydroponics is discussed in this publication, see on CMC compost is available from ATTRA onATTRA’s Hydroponic Vegetable Production for request.more in-depth information. ATTRA publications that explain sustainableSoil Culture fertility management in more detail include Sustainable Soil Management, Non-ConventionalIn soil culture, also known as ground culture, Soil Amendments and Farm-Scale Compostingvegetables are raised on level ground as well as Resource mounded beds. Soil culture is more popularwith organic growers than hydroponic methods. Cover Cropping in Ground Culture SystemsOne of the reasons organic growers prefer soilculture to hydroponics is that soil-building Cover crops fit nicely into ground culturepractices are an already familiar concept based systems that include a crop-free rest period (inon decades of research and experience. summer, for example). Short-term cover crops include legumes, buckwheat, annual ryegrass,Production techniques used in ground culture oats, rapeseed, and oilseed radish. Often, theare similar to intensive market gardening choice of cover crop will depend on themethods used in the field. Rear-tine tillers or vegetable rotation and the intended purpose.mechanical spaders are used in soil preparation, Cover crops can replenish and help buildand specialized wheel hoes and hand tools are organic matter in soils, increase microbialused for cultivation and weed control. Organic activity, add nitrogen, and help prevent orfertilizers and soil amendments are extensively suppress diseases and nematodes, especiallyused to feed the soil. when brassica and oilseed radish cover crops are used.In Quebec, organic farmers raising greenhousetomatoes by the ground culture method use two Marty Legant, who raises 2 acres of organicrows per bed raised about one foot high. winter tomatoes by the ground culture methodCompost is applied at a rate of 1.2 to 2.4 cubic in Parowan, Utah, has an 8-week period inyards per 1000 sq. feet. The first year it is which cover crops occupy his greenhouse. He’s ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 8
  9. 9. raised buckwheat and oats in the past, and has hand hoeing, mechanical cultivation, steamplans to try hairy vetch. At plowdown, he pasteurization, soil solarization, mulchinginoculates the green manure with vitamin B-12, (fabric, plastic, or organic mulches), and poultrysugar, and a catalyst to help speed grazing.decomposition and enhance humus formation. Poultry grazing is a unique method ofAnna Edey, whose primary commercial crop “biological” weed control that may be an optionis salad greens, recommends the following for some greenhouse growers. This system is(14). used by Lynn Shanks, a vegetable grower near For average soil, add, per square Bixby, Oklahoma (15). Mr. Shanks raises yard: 4 gallons of compost, 4 cubic greenhouse tomatoes and early-season feet of peat moss, 1-2 pounds of cantaloupes by the ground culture method. To soft rock phosphate, 1-2 pounds of manage weeds, he houses jungle fowl from greensand, and lime if needed. India in the greenhouse to “graze” on weeds. Spread it out evenly and blend The jungle fowl are also deft at picking insects thoroughly by rototilling twice, off the vegetable plants without damaging any rake it smooth and level, and then fruits. (Jungle fowl should not be confused with water well enough to soak through the domesticated chicken, which is notorious for to the full depth. pecking at tomatoes in the garden). The impressive aspect of this system is that weeding The next day sow buckwheat requires no labor, mulching, or cultivation on seed, spaced ¼ to ½ inch apart, the part of Shanks’ family. cover lightly and water it well. Let the buckwheat grow for Soil Disinfection in Ground Culture Systems about two to three weeks, to about 10-12 inches high, then A major concern in ground culture systems is turn it under and sow another soil sterilization or pasteurization for control of round of buckwheat. Repeat soil-borne pathogens. Methods of these buckwheat cycles until the disinfection—including solarization, steam, growing beds in the greenhouse electrical heat, and biological control—are are ready to be filled. covered in the ATTRA publication titled Integrated Pest Management for Greenhouse Crops. In order to maintain highest soil fertility, the soil needs to be Resources on Ground Culture Systems enriched with compost and minerals four to five times per The New Organic Grower, a 340-page book by year. I recommend that every Eliot Coleman, is one of the best resources on area of the greenhouse…receive intensive market gardening. Many of the a buckwheat treatment once a techniques he describes—especially fertility, year. weed control, and soil blocking—are readily adaptable to greenhouse ground culture.An alternative to growing cover crops inside the Coleman has also written two books dealinggreenhouse is incorporation of freshly chopped with year-round production of food. The first iscover crops or pasture-grown forages Four-Season Harvest, which focuses on usingtransported from a nearby field. These are cold frames and high tunnels. The second is Thecalled green-leaf manures. Winter Harvest Manual: Farming the Back Side of the Calendar. This small book concentrates on Weed Control in Ground Culture Systems commercial winter production of fresh vegetables in cold climates withoutStrategies for non-herbicidal weed control supplementary heat. See the Resources sectioninside the greenhouse include a combination of for more information. ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 9
  10. 10. Soilless Culture Adapting bag culture to standard soilless production in a certified organic greenhouseSoilless culture methods usually have higher operation requires specially formulated organicyields than ground culture systems. Another potting mixes. An organic potting mix shouldadvantage of a soilless system is easier control not include any synthetic fertilizers or wettingof disease problems. In the soilless techniques agents. Growers can purchase certified organicdescribed below, the media can be disposed of potting mixes from a commercial supplier, orafter one crop has been grown, or it can be mix their own. Organic bag cultured vegetablespasteurized relatively easily. may include a combination of incorporated, topdressed, liquid-fed, and foliar-fedBag Culture fertilization systems. See ATTRA’s Organic Potting Mixes publication for a summary of media and fertilizers that can be used in organic Bag culture has become the preferred production systems; this publication includes method of greenhouse vegetable production recipes for organic potting mixes collected from in many parts of the U.S. because it is easy the alternative agriculture literature and to establish and manage successfully. interviews with organic farmers. Adapting bag culture to soluble hydroponics orIn bag culture, plants are grown in a soilless bioponics requires special hydroponic formulasmedium contained in lay-flat or upright and ingredients. These are covered inpolyethylene bags (2–5 gallons in size) and fed ATTRA’s Hydroponic Vegetable Productionwith liquid fertilizers through drip irrigation publication.lines. Media can be peat/vermiculite, sawdust,rockwool, rice hulls, pine bark, peanut hulls, or Vertical Towersmixes of any of those. Bag culture is adaptableto both aggregate hydroponics fed with liquid A form of bag culture is the vertical tower.fertilizers as well as standard soilless culture, in Long bags full of media are hung fromwhich the bulk of fertility is supplied via support wires or beams, and plants are placedcompost-based potting mixes. in slits or holes made on the sides of the bag. The appeal of this system is the very efficientUpright bags should be purchased at use of greenhouse space; since the plants aregreenhouse supply houses, since household using vertical space, very little floor space isgarbage bags are usually not strong enough. needed.Upright bags usually contain one plant per bag.Lay-flat bags are closed and are made of 4-mil, The most popular vertical tower is a patentedUV-protected polyethylene. Lay-flat bags often system called Verti-Gro. Verti-Gro uses square,have two or three plants per bag. Bags are most styrofoam pots, which are stacked 8–10 potsoften placed in double rows in the greenhouse. high and can be re-used for 5–10 years. Tim Carpenter, who owns the company,Bag culture is well suited to the production of recommends using perlite and coir (coconutupright and vining crops like tomatoes, fiber) for media. Fertilizer is supplied by a dripcucumbers, and peppers. Bag culture has irrigation system, in which solution flows frombecome the preferred method of greenhouse the topmost to the bottom box and into a gravelvegetable production in many parts of the U.S. support base, where it can be captured and re-because it is easy to establish and manage used. Crops that have been grown with thissuccessfully. One problem with bag culture is system include lettuces, strawberries, herbs,the potential for excess fertilizer solution to tomatoes, greens, spinach, nasturtium, and cutleach out of the drainage holes in the bags and flowers. For more information on this system,into the greenhouse soil. contact: ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 10
  11. 11. Verti-Gro, Inc. byproducts promote plant growth by warming 720 Griffin Rd. the roots and enriching the greenhouse Lady Lake, FL 32159 atmosphere. 800-955-6757 352-750-4202 In considering straw bale culture, the cost of the bales and topcapping compared with costs of a comparable production system such as bagStraw Bale Culture culture, will need to be weighed. Also, in organic culture, a major factor would be theStraw bale culture was an important method of availability of certified organic straw. Herbicidegreenhouse cucumber production in Europe and residues in straw can cause serious injury toCanada prior to the development of rockwool greenhouse crops.and NFT hydroponics. Bale culture can be Canadian studies conducted in the 1960s and 1970s showed that: In considering straw bale culture, the cost of the bales and topcapping • Spring-grown cucumbers grown on straw compared with costs of a comparable bales yielded an average of 21% more fruit production system such as bag culture, than soil-grown plants, although fall-sown will need to be weighed. plants did not have a yield increase. • Wheat straw bales provided the best results, followed by clover straw. Timothy/alfalfaespecially useful as a method to avoid soils hay bales gave poor results.contaminated with diseases or in greenhouses • Using half a bale per plant caused nowith concrete or gravel floors. Based on limited significant loss in yield.experience in Canada in adapting straw bale • Using a plastic sheet under the bales causedculture to organics, this method appears to have a 9% reduction in yieldmerit where one of the aforementioned • There is little or no difference in yieldconditions exists. between bales placed on the soil surface and those buried or half-buried in a trench.In bale culture, the greenhouse floor can be • Growing in straw bales was economicallyconcrete or lined with plastic or fabric mulch, feasible for spring-sown plants (16).and bales are laid out in rows. Bales are pre-wetted with manure tea, which initiates Missouri farmer Eric Hemple raises organicdecomposition and causes the bales to heat up. arugula, squash, green beans, onions, On the average, about 7 gallons of water are eggplant, tomatoes, and cucumbers using therequired for a normal 50 lb. bale. When the straw bale method. A neighbor providestemperature of the bales cools down to below organic straw bales at a price of $3 each.110° F, they are capped with six inches of a Hemple places the bales between two sheets ofcompost-based potting mix to accommodate corrugated tin braced with stakes to create athe root balls of the transplants. Normally, more uniform growing surface. He uses aplanting would take place on about the sterile potting mix as his capping medium andeleventh day. bone meal, blood meal, fish emulsion, and rock phosphate as his fertilizers. Hemple usesFertilizers topdressed to the bales include dry a drip irrigation system and warns that carefulbone meal, sul-po-mag, and an organic nitrogen attention to watering is essential, as are propersource. Manure tea, seaweed, and fish-seaweed nutrient levels. He sells all his products atblends are used as liquid fertilizers. As the retail and estimates that he is receiving a grossbales continue to ferment and decompose, heat return of 50 cents per square foot of bale spaceand carbon dioxide are generated and these per week (17). ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 11
  12. 12. Shallow Bed Culture and are more typical of standard trough culture using a soilless mix. They’ve achieved goodShallow bed culture, also known as thin layer success raising a variety of vegetable cropsculture, is the production of sprouts or using locally available materials such as leafherbaceous herbs and vegetables in a thin mold and compost.layer—1 to 3 inches in depth—of potting mixor compost laid on top of plastic mulch or ECHO has published several reports on shallowwoven weed barrier. Herbaceous crops bed culture and low-tech hydroponics. For moreadapted to shallow bed culture include information, see their web site atspecialty lettuces, greens, cresses, and selected herbs. or contact them at:At least one commercial sprout grower in Educational Concerns for HungerCalifornia uses this method in the production of Organization (ECHO)organic wheat grass, sunflower, and buckwheat 17391 Durrance Rd.sprouts. Root-zone heating tubes are laid North Ft. Myers, FL 33917underneath the plastic to provide bottom heat. 941-543-3246In turn, they rest on top of polystyrene panels http://www.echonet.orglaid directly over the greenhouse soil. Gas-firedwater heaters are used to heat the water, but Hydroponicssuch a system could easily be retrofitted to solarcollectors located outside the greenhouse. In hydroponics, plants are grown in a soillessNarrow boards are laid out every three feet to medium and fed with fertilizer nutrientswalk up and down between the beds to seed, dissolved in solution. There are two broadwater, and harvest. categories of hydroponics: liquid hydroponics and aggregate hydroponics.Jay Fulbright, a commercial lettuce and specialtygreens grower in Arkansas, has three growing Liquid systems feature the nutrient filmsystems. In the first, he amends his soil with technique (NFT), aeroponics, floating raft, andcompost and pelletized chicken litter and plants noncirculating water culture. Aggregate systemsdirectly into the ground. In the second system, include inert, organic, and mixed mediahe uses tables made of 2x8 lumber and places contained in bag, trough, trench, and bench3½” of compost onto 2x4 welded wire mesh, setups.covered with perforated plastic to allow fordrainage. All the greens are hand-harvested Liquid systems like NFT are often managed asusing this system. The third method involves closed, or recirculating systems. Aggregateplacing 4” of compost and chicken litter directly systems are commonly managed as open, oronto polypropylene sheets laid on the ground. flood and drain fertigation systems.Jay devised the third method in order to cutdown on labor; he hopes to be able to use a There are three basic approaches to organicsalad harvester. He is now harvesting an hydroponic vegetable production: a) solubleaverage of 300 pounds of lettuce per week, organics, also known as hydro-organics, b)which he sells to restaurants and specialty integration of hydroponics with aquaculture, alsogroceries. known as aquaponics, and c) bioponics.Education Concerns for Hunger Organization Hydro-organics is based on hydroponic solutions(ECHO), a nonprofit organization that works in derived from organic fertilizers like fish meal,agriculture development, is promoting the spray-dried blood, and guano. Aquaponics isshallow bed method as a technique for rooftop based on recirculating aquaculture in whichgardening in urban settings. The beds they irrigation effluent from fish tanks is used todescribe are deeper—3 to 6 inches in depth— fertigate sand or gravel cultured hydroponic ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 12
  13. 13. vegetables. For more information, see the for as little as $500 to $1,500. Hoop houses areATTRA publication Aquaponics. Bioponics, or similar to plastic Quonset greenhouses but are“living hydroponics,” is based on inoculating the not equipped to heat or cool, and are usedhydroponic medium with microorganisms. See primarily for season extension. SolarATTRA’s Hydroponic Vegetable Production for greenhouses work fine for small-scalemore information on bioponics. production—especially for the production of transplants and cool-season lettuces—but may not provide adequate space or climate control The greenhouse vegetable business is for commercial tomato, cucumber, or pepper competitive. production. Otto Wells, a professor at the University of NewThe key difference between organic and chemical Hampshire, found that growing tomatoes in anhydroponics is the source of fertility and presence unheated 14x96-foot hoop house in Newof microorganisms. Microbes are essential to Hampshire could be profitable, if he realized aorganic systems because they help regulate pH yield of 2000 pounds and sold the tomatoes forand availability of nutrients. In addition, $1.60/lb. Using these estimates, the growerbioponic researchers claim that enzymes would earn a net return of 71 cents per poundproduced by the microbes interact with plant (18).roots and stimulate biochemical processes in theplants which enhance the flavor of bioponic The greenhouse vegetable business isproduce. For more information on hydroponics, competitive. Wholesale markets for off-seasonsee ATTRA’s publication Hydroponic Vegetable produce often become saturated and causeProduction. produce prices to drop. Competition stems from an established domestic industry as well asVariety Selection Dutch imports. In addition, field-grown Mexican produce frequently sells at half theVariety or cultivar selection plays an important price of greenhouse produce. Local androle in greenhouse vegetable production. specialty markets provide alternative outlets,Cultivars often originate in greenhouse but the volume of produce that can be moved isbreeding programs where selection is based on much less than what can be shipped to distantdisease resistance and ability to perform under markets.greenhouse climatic conditions. Greenhouseseed vendors and the Cooperative Extension Greenhouse vegetable yields determineService can recommend appropriate cultivars. potential gross sales. Typical yields ofSeed suppliers are listed in the Resources greenhouse tomatoes are 20 to 30 lbs. per vine,section below. See the ATTRA series of or 2–3 lbs. per square foot. Greenhousepublications on specific greenhouse crops for cucumbers yield around 2 dozen fruits per vine.other recommendations. Greenhouse peppers yield 2½ -3 lbs./sq. ft. A study conducted in Missouri in the winter ofEconomics of Greenhouse Vegetable 1995–96 showed that supplemental lighting ofProduction tomatoes increased total yields from 12,444 kg to 18,840 kg. Because the lighted tomatoes wereGreenhouses are expensive to build and operate. larger, they brought a better price and resultedA commercial greenhouse (30’ x 100’) with in additional revenues of $25,000 (19).complete heating, cooling, and ventilationsystems will cost between $10,000 to $30,000 to Prior to sinking lots of money into a greenhouseerect and equip. venture, growers should examine produce prices in their region and estimate their cost ofLow cost greenhouses—like hoop houses and production. Historically, the breakeven priceattached solar greenhouses—can be constructed for most greenhouse tomatoes has been around ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 13
  14. 14. 75 cents per pound, with selling prices ranging Pollinating by hand is expensive (in terms offrom 90 cents to $1.60 per pound. The break- labor), tedious, and time-consuming. Severaleven price for cucumbers is similar—around 75 companies are now raising bumblebees to becents per pound (18-21). used for indoor pollination. Although the hives are expensive, they pay for themselves many times over. Eliot Coleman and his wife Barbara Damrosch raise organic produce in their There have also been many new biorational greenhouses in Maine. They charge pesticides in the last five years. Some of these $6.25/lb for salad mix, $3.00/lb. for bulk biorational pesticides (also known as least- spinach, $1.25-$2.00 for carrots, and toxic, environmentally friendly, or $3.00/lb for baby turnips. They dropped biopesticides) include Bt, Beauveria bassiana, and Cinnamite™, which was just released in scallions because they couldn’t make 1999 for control of several greenhouse pests. money from them (22). Use of biological control agents has alsoEstimates of net income from conventional increased in the last decade. Much more isgreenhouse tomatoes range from $3,100 to known about how to use these insects to their$18,500 per greenhouse unit (21, 23). These fullest advantage and about how to applyestimates are for good yields and favorable insecticides while preserving predators. Formarket conditions. Low yields, or a dip in the more information on these, see the ATTRAmarket, can lead to negative returns to the publication Integrated Pest Management forgrower. Greenhouse Crops.The following estimates from 1994 are Additionally, new cultivars bred exclusively forassociated with a double polyethylene greenhouse growing are now available to smallgreenhouse: the greenhouse itself would cost growers. Seed vendors like DeRuiters areabout $6–$7 per square foot; hydroponic constantly testing new cultivars for greenhouseequipment would be an additional $1.50–$2.00 production. Although seed for greenhouseper square foot; land cost, site preparation, crops is still more expensive than for field crops,foundations, concrete floors, and utilities it has become more affordable. Growerswould be an extra $3.50–$4.00 per square foot themselves have been testing cultivars for(24). suitability in greenhouse work, especially in the area of heirloom vegetables.As a suggestion, growers should gather all theeconomic data they can about the greenhouse Another change that is occurring is in the fieldvegetable business before building a of greenhouse coverings. Modern greenhousegreenhouse. Also, take a look at other plastics are resistant to breakdown fromgreenhouse business enterprises and determine ultraviolet light and are rated to last severalif vegetables are really the best deal. As an years. This reduces annual expenses forexample, greenhouse vegetable growers in some materials, labor to reglaze, and fees for landfillparts of the country have begun to diversify into disposal. Structured sheets are the deluxebedding plants because that market is more alternative to Quonset-style plastic houses.lucrative. They are more expensive to purchase and install, but they provide optimumDevelopments in the Greenhouse Industry in environmental controls and have a very longthe Last Decade life. Research into the chemistry associated with greenhouse glazing is aimed at energyOne exciting development is the introduction of savings, pest control, and enhancement of plantbumblebees for greenhouse tomato pollination. growth. ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 14
  15. 15. Summary 8) Gagnon, Bernard and Sylvain Berrouard. 1994. Effects of several organic fertilizers onOrganic greenhouse vegetable production has growth of greenhouse tomato transplants.potential as a niche market for out-of-season Canadian Journal of Plant Science. January. p. 167–168.produce and as a sustainable method ofproduction. Soil-based systems are readily 9) Schwankl, Lawrence J., and Glenn McGourty.adaptable to certified organic production, but 1992. Organic fertilizers can be injectedspecial care must be taken for soil-borne disease through low-volume irrigation systems.control. Soilless systems can also be adapted to California Agriculture. September– culture, and systems like bag culture are p. 21-23.easy to get into. Little research is available forspecific organic production systems, potting 10) Morgan, Lynette. 1997. Organic fertilizersmixes, and fertilizer regimens, however, and for hydroponics. The Growing Edge.growers must use best available knowledge and November–December. p. 32–35, 37–39.improvise. 11) McMullin, Eric and Warren Clark. 1993. Riding Israel’s vegetable boom. AmericanReferences: Vegetable Grower. March. p. 34–35.1) Snyder, Richard G. 1993. The U.S. 12) Hickman, Gary. 1988. Greenhouse vegetable greenhouse vegetable industry update and production in the United States—1899–1988— greenhouse vegetables in Mississippi. p. 78– A statistical review. p. 6-8. In: Proceedings of 82. Proceedings of the American Greenhouse the American Greenhouse Vegetable Growers Vegetable Growers Conference. Held Aug. conference. Held Sept. 6–9, Orlando, FL. 19–21, Denver, CO. 13) Uta Luebke. 1994. Humus Management2) Census of Agriculture. 1997. U.S. Census of Seminar. Bird-in-Hand Village, PA. Horticulture Specialties. Bureau of the Census, U.S. Department of Commerce, 14) Edey, Anna. 1998. Solviva: How to Grow Washington, D.C. $500,000 on One Acre and Peace on Earth. Trailblazer Press, Martha’s Vineyard, MA.3) Anon. 1999. Agriculture and Agri-Food 221 p. Canada: Introduction to the Greenhouse Vegetable Industry. Greenhouse & 15) Lynn Shanks. 1994. Oklahoma State Processing Crops Research Centre, Ontario, University Field Day, Bixby, OK. Canada. 16) Loughton, Arthur. 1977. Straw-bale culture 16 p. of greenhouse crops. p. 208–215. In: Merle H. Jensen (ed.) Proceedings of the4) Jones, J. Benton, Jr. 1999. Tomato Plant International Symposium on Controlled- Culture. CRC Press, Boca Raton, FL. p. 90. Environment Agriculture. Held April 7–8, 1977, Tucson, AZ.5) Meisterheim, Rick. 1998. SARE grant project 17) Flaim, John. 1999. Growing in haybales. — final report. Project No. FNC 96–139. 4 p. Small Farm Today. August. p. 58–60.6) USDA Study Team on Organic Farming. 18) Byczynski, Lynn. 1993. Greenhouse tomato 1980. Report and Recommendations on considerations. Growing for Market. April. Organic Farming. USDA, Washington, DC. p. 1, 12. 94 p. 19) Larson, Arley, Alex Ching, and Scott Walk.7) Anderson, Robert G. and Robert Hadad. 1996. Economics of greenhouse tomato 1999. Nutrient analysis of organic fertilizers production in the rural north central U.S. for greenhouse vegetable production. ActaHorticulturae. No. 429. p. 75–80. HortScience. June. p. 463. Abstract. ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 15
  16. 16. 20) Schatzer, Raymond Joe, B. Dean McCraw, Stokes Seeds, Inc. Ahmed Al-Abdulkador and Harry P. Mapp. P.O. Box 548 1994. The Economics of Bag Culture Buffalo, NY 14240 Greenhouse Tomatoes in Oklahoma. Current 800-396-9238 Farm Economics. December. p. 29–40. Sell some untreated seed.21) Al-Abdulkador, Ahmed M. 1992. Economic Feasibility of Greenhouse Vegetable Suppliers of Organic Fertilizers: Production in Oklahoma. Oklahoma State (For a complete listing of suppliers of organic University, Stillwater. M.S. Thesis. 139 p. fertilizers, see ATTRA’s publication Sources for Organic Fertilizers & Amendments.)22) English, Jean. 1999. Seasoned farmers spread the word about year-round growing. Algamin Maine Organic Farmer & Gardener. June- Peaceful Valley Farm Supply August. p. 20–23. PO Box 2209 Grass Valley, CA 9594523) Hochmuth, George J. 1992. Production and 888-784-1722 economics of rockwool tomatoes in Florida. p. 40–46. In: Proceedings of the 13th Annual GreenAll Fish Emulsion Conference on Hydroponics. Hydroponic Peaceful Valley Farm Supply (see address Society of America, Concord, CA. above)24) Anon. 1998. Greenhouse cucumbers. Neptune’s Harvest Neptune’s Harvest Fertilizer gh.html. 6 p. 88 Commercial Street Gloucester, MA 01930Greenhouse Vegetable Seed Sources: 800-259-4769Crop King Maxicrop5050 Greenwich Rd. Maxicrop International, Inc.Seville, OH 44273 [Contact: Per Ohrstrom]800-321-5656 PO Box 964 Arlington Heights, IL 60006 Sell treated seed only. 800-535-7964De Ruiter Seeds, Inc. Mermaid’s Fish Powder3001 Bethel Rd., Suite 118 Peaceful Valley Farm Supply (see addressColumbus, OH 43220 above)614-459-1498 Spray-dried protein fertilizers Can special-order untreated seed. California Spray Dry Co. P.O. Box 5035Hydro-Gardens, Inc. Stockton, CA 95205P.O. Box 25845 209-948-0209Colorado Springs, CO 80936888-693-0578 Resources: Sell untreated and treated seed. Books:Petoseed Co., Inc. Coleman, Eliot. 1992. Four Season Harvest. Chelsea1905 Lirio Ave. Green, Post Mills, VT. 212 p.Saticoy, CA 93004 Inspired by Scott and Helen Nearings garden in805-647-7386 the late 60s and based on the authors success with Sell untreated and treated seed. harvesting fresh vegetables year-round in New England, this book contains details on design, construction, and management of the outdoor garden, cold frames, tunnels, ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 16
  17. 17. and root cellars. It includes growing tips for 50 vegetable financing of greenhouse vegetables. It is available forcrops, a planting schedule for extended harvests for all $10.00; make checks payable to TAEX. Contact:locations in the US, and sources of tools and supplies. Greenhouse PublicationsAvailable for 19.95 from: Room 225 HFSB Chelsea Green Publishing Texas A&M University P.O. Box 513 College Station, TX 77843-2134 Lebanon, NH 03766 800-639-4099 Hydro-Gardens, Inc. in Colorado Springs, Colorado, carries a large selection of publications onColeman, Eliot. 1995. The New Organic Grower: A greenhouse vegetable production. See their web siteMasters Manual of Tools and Techniques for the for a complete listing. Contact:Home and Market Gardener, 2nd Ed. Chelsea Green, Hydro-Gardens, Inc.White River Junction, VT. 340 p. P.O. Box 25845 Written primarily for the market gardener with 1 Colorado Springs, CO 80936to 5 acres, the book is based on over 25 years of study and 888-693-0578personal experience. It covers everything from land to marketing, including soil fertility management,field layout and spacing, rotations, direct seeding, Selected Publications available from Hydro-Gardens,transplanting, cultivation, season extension, and Inc.integration of livestock into the vegetable system. Extensivechapter notes and annotated bibliography. Available for Florida Greenhouse Vegetable Production Handbook.$24.95 from Chelsea Green (see address above). $19.95Coleman, Eliot and Barbara Damrosch. 1998. The Greenhouse Tomatoes, Lettuce & Cucumbers, by S.H.Winter Harvest Manual. Four Season Farm, Wittwer and S. Honma. $17.95Harborside, ME. 56 p. Emphasis is on commercial production of Nutritional Diseases in Glasshouse Tomatoes,greenhouse vegetables. Available for $15 from: Cucumbers, and Lettuce, by Roorda van Eysinga and Four Season Farm K.W. Smilde. $53 RR Box 14 Harborside, ME 04642 Vertical Plant Production Manual. $35Grotzke, Heinz. 1990. Biodynamic Greenhouse Greenhouse Tomato Instructional & Plant CultureManagement. Biodynamic Farming and Gardening Manual. $10Association, Kimberton, PA. 112 p. One of the few publications specific to organic Growing Greenhouse Tomatoes in Soil and in Soillessgreenhousing. Grotzke has chapters on soils, fertilization, Media. Available only on the Internet.and biodynamic preparations, but they are short ontechnique and mostly contain insights on the biodynamicview of greenhousing. He states that soilless culture Soilless Culture of Commercial Greenhousesystems lack essential microorganism activity and Tomatoes. $3therefore only soil-based potting mixes or ground culturesystems can produce biodynamic quality produce. Greenhouse Cucumber Instructional and PlantAvailable for $12 from: Culture Manual. $10 Fertile Ground Books PO Box 2008 Growing Greenhouse Cucumbers in Soil and in Davis, CA 95617 Soilless Media. Available only on the Internet. 800-540-0170 Cucumber Diseases, by W.R. Jarvis and V.W. Nuttall. $5Twenty-one separate fact sheets comprise the 137- The Cultivation of European Cucumbers inpage Greenhouse Vegetable Guide, which treats topics Greenhouses. By Nunhems Seed Company, Holland.ranging from locating and constructing the $5greenhouse to insects and diseases attackinggreenhouse vegetables. Included is an 18-page fact Greenhouse Pepper Pamphlet. $2sheet on production economics, marketing, and ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 17
  18. 18. Periodicals: GrowerTalks Ball Publishing Co.The Growing Edge is a bi-monthly magazine that P.O. Box 9focuses on hydroponics and high-tech gardening 335 N. River Streetfrom an ecological angle. The emphasis is on Batavia, IL 60510-0009greenhouses, hydroponics, artificial lighting, drip 630-208-9080irrigation, and other protected culture methods. 630-208-9350 FaxSpecial issues have featured articles on bioponics and http://www.growertalks.comorganic soilless culture. Back issues are available. $25/year for 14 issuesContact: The Growing Edge American Vegetable Grower New Moon Publishing Meister Publishing Co. 341 SW 2nd Street 37733 Euclid Avenue Corvallis, OR 97333 Willoughby, OH 44094 800-888-6785 440-942-2000 440-942-0662 Fax $26.95/year $15.95/yr, 12 issues. Buyers Guide published inTrade Publications: July issue.The trade journals listed below regularly reviewgreenhouse developments and products. The buyers guide Web Sites:issues are a comprehensive source of supplies. http://www.ces.ncsu/edu/depts/hort/hil/hil-32-a.Greenhouse Grower htmlMeister Publishing Company Greenhouse Vegetable List of References37733 Euclid Ave.Willoughby, OH 44094 html440-942-0662 Fax Greenhouse Vegetable Production New Mexico State University $29/year for 12 issues; Buyer’s Guide issue every An excellent overview of greenhouse vegetablesummer production. The circular includes information on Site Selection, Greenhouse Design, GreenhouseGMPro (Greenhouse Management & Production) Coverings, Environment, Soil Culture,Branch-Smith Publishing Hydroponic Culture, Carbon Dioxide, IPM, andPO Box 1868 Disease. The circular is specific to tomato,Fort Worth, TX 76101 cucumber, and lettuce production.800-434-6776817-882-4120 http://aggie-817-882-4121 Fax html 12 issues/year; free to qualified greenhouse http://aggie-growers; $96/year for non-growers htmlGreenhouse Product News Texas Greenhouse Management HandbookScranton Gillette Communications, Inc. Texas A&M University, Aggie Horticulture380 E. Northwest Hwy. Comprehensive information on GreenhouseDes Plaines, IL 60016-2282 Structures, Greenhouse Heating Requirements,847-298-6622 Growing Media, Growing Media & pH, Fertilizing847-390-0408 Fax Greenhouse Crops, Calculating Parts Per Million, Diagnosing Nutritional Deficiencies, Irrigating $30/year for 12 issues Greenhouse Crops, Monitoring the Quality of Irrigation Water, Treating Irrigation Water, Managing Soluble Salts, Air, Water and Media...Putting Them All Together, and Additional References for Greenhouse Management. ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 18
  19. 19. A Greenhouse Business Controlled Environment Agriculture InformationMississippi State University, Cooperative Extension Resources 1996Service Cornell University College of Agriculture and Life This information sheet provides an overview of Sciences factors to be considered by the greenhouse business. An online resource listing of publications (books The cost estimates used are intended for & journals) on the following topics: Conferences, informational purposes only, since costs vary Trade Journals, Newsletters, Industry depending on the supplier and crop mix selected. Organizations, Greenhouse Suppliers, Diagnostic Services, Business Planning & Operation, Cropping Systems, Greenhouse Management,Greenhouse Industry Trade Show On-Line Photosynthesis Management, Greenhouse Crop Online resource to greenhouse growers, suppliers, Production, General Crop Production, Postbuyers, and researchers. Harvest Horticulture, and Interiorscaping. commhort-30.html The electronic version of OrganicUpdate on Production Costs/Expected Returns Greenhouse Vegetable ProductionBudget for Greenhouse is located at:Virginia Cooperative Extension By Lane Greer and Steve Diver NCAT Agriculture Specialists January, 2000 The ATTRA Project is operated by the National Center for Appropriate Technology under a grant from the Rural Business-Cooperative Service, U.S. Department of Agriculture. These organizations do not recommend or endorse products, companies, or individuals. ATTRA is located in the Ozark Mountains at the University of Arkansas in Fayetteville at P.O. Box 3657, Fayetteville, AR 72702. ATTRA staff members prefer to receive requests for information about sustainable agriculture via the toll-free number 800-346-9140. ATTRA // ORGANIC GREENHOUSE VEGETABLE PRODUCTION Page 19