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Home  > Question of the Week

Question of the Week

Permalink What are some resources for hydroponic greenhouse production and economic information?


Answer: Thank you for contacting ATTRA for resources on hydroponic greenhouse production.

General Greenhouse Production Considerations:
Enterprise Budgets

If you intend for this to be a profit making venture, it is very important to consider the costs and potential earnings of your enterprise. There are several enterprise budgets available for greenhouse tomatoes and other vegetables. Greenhouse vegetable yields determine potential gross sales. Much of the information in this letter is referenced from the ATTRA publication “Organic Greenhouse Vegetable Production.” I would encourage you to read this publication if you have not already. This is a good introduction to the considerations you should make when planning a greenhouse operation. The authors estimate that typical yields of greenhouse tomatoes are 20 to 30 lbs. per vine, or 2-3 lbs. per square foot. Greenhouse cucumbers yield around 2 dozen fruits per vine. Greenhouse peppers yield 2½ -3 lbs./sq. ft. A study conducted in Missouri in the winter of 1995-96 showed that supplemental lighting of tomatoes increased total yields from 12,444 kg to 18,840 kg. Because the lighted tomatoes were larger, they brought a better price and resulted in additional revenues of $25,000.

Prior to sinking lots of money into a greenhouse venture, growers should examine produce prices in their region and estimate their cost of production. Historically, the breakeven price for most greenhouse tomatoes has been around 75 cents per pound, with selling prices ranging from 90 cents to $1.60 per pound. The break-even price for cucumbers is similar–around 75 cents per pound. Estimates of net income from conventional greenhouse tomatoes range from $3,100 to $18,500 per greenhouse unit. These estimates are for good yields and favorable market conditions. Low yields, or a dip in the market, can lead to negative returns to the grower.

The following estimates from 1994 are associated with a double polyethylene greenhouse: the greenhouse itself would cost about $6-$7 per square foot; land cost, site preparation, foundations, concrete floors, and utilities would be an extra $3.50-$4.00 per square foot.

The ATTRA resource list “Greenhouse and Hydroponic Resources on the Internet,” contains several enterprise budgets for regular greenhouse crops (i.e. not hydroponic).

Some other web-based enterprise budgets are listed below:
Ohio State University Hydroponic web site has an interactive enterprise budgeting tool.

North Florida Greenhouse Cash Flow analysis
A cash flow analysis using tomatoes as an example

For general information on business planning and how to construct a good one see this overview:
Ag Alternatives: Business Planning—the Pennsylvania State University

General information about organic hydroponic production:

The power point presentation by Dr. Mary Peet from North Carolina State University overviews some organic substitutions for nutrient and pest management in hydroponic systems. Also the publication titled “Organic Hydroponics” discusses, mainly, different types of nutrient solution options for an organic hydroponic operation. The link to both of these publications is listed below under “Further Resources,” however, the “Organic Hydroponics” article is from Growing Edge magazine, and they charge $5.00 for obtaining this publication. I have also listed an additional link to a study the Mary Peet did on maintaining nutrient balances in organic soluble fertilizers.

Consultants and Suppliers:
In most circumstances, larger scale commercial greenhouse suppliers have technical staff that consult you on set-up and design of your greenhouse facility. I have listed greenhouse suppliers, as well as companies that have categorized themselves as hydroponic consultants.

They provide both consulting and supplies. They offer supplies and consulting for large scale hydroponic oprations. Colorado has several large-scale hydroponic operations in the state.
P.O. Box 25845
Colorado Springs, CO 80936-5845

American Hydro
They are commercial suppliers of hydroponic greenhouses and equipment with limited consulting.

AGRO Dynamics
“Agro Dynamics is focused on supplying innovative, state-of-the-art and high quality products.” They provide both consulting and greenhouse and hydroponic supplies.
204 Airline Drive ; Suite 900
Coppell, TX 75019
Tel: (+) 800 872-2476
Fax: (+) 972 829-8039
English/ Spanish e-mail:

Crop King consults, provides workshops, and sells commercial-scale hydroponic systems. Below is a link to a price list of their gutter connected greenhouses. These are most commonly used in large scale commercial operations.
Below is a link to training opportunities on hydroponic production:

Further Resources:
Landers, Melvin. 2001. Organic Hydroponics. Growing Edge. May/ June 2001.
This is a back issue that Growing Edge is currently charging $5.00 for. The link to order it and other relevant hydroponic information online is:

Peet, Mary. (no date). Organic Hydroponics. North Carolina State University. Power Point Presentation.

Maintaining Nutrient Balances in Systems Utilizing Soluble Organic Fertilizers
Janet Miles and Mary Peet, NCSU
OFRF Project Report, June 2002

Diver, Steve. 2000. Organic Greenhouse Vegetable Production
Horticulture Systems Guide. ATTRA Publication #IP078



Permalink What can you tell me about weed control for asparagus?


Thank you for your recent request for information from ATTRA, the National Sustainable Agriculture Information Service regarding weed management in your newly planted asparagus.

As you are finding out weed management is critical to growing asparagus, since it is a perennial crop and tillage options are limited once the asparagus is planted—especially during the spear and fern stages of production. I usually recommend a strict cover-cropping strategy before the asparagus goes in, but since you have existing plants I will recommend a few options.

The weed management strategies are different for annuals than perennials. I will make some recommendations based on each kind of weed.

Annual weeds will be easier to control in your asparagus crop than perennials. At this point, hoeing and hand weeding may be your best option, but shortly after this, you can apply a mulch either living or straw to help keep down the weeds. A living mulch of oats and peas could be seeded in the fall, then allowed to winterkill and provide a cover to keep the weeds at bay. If you choose to use straw, be sure that it is indeed straw and not spent hay, which can make your weed problem worse.

Another option for annual weeds the following spring before the asparagus begins to emerge, is to use a flame weeder. This product can efficiently and effectively help with weed management if done early on. It is important that you flame weed before the tips emerge. As a general rule, flame weeding is most effective against annual broadleaf weeds, moderately effective against annual grasses, and a poor option for perennial weed management.

For perennial and annual weeds during spear and fern production weeder geese are an option. In order to make cost comparisons between geese and other weed control methods, you will need to keep a record of the time spent moving, feeding, and watering the geese. A good book on raising geese and using weeder geese is The Book of Geese available from many sources, including Metzer Farms. This book along with more information on this topic is available by visiting their web site:

Another option for perennial weeds, besides hand-weeding, is to use a burn-down organic herbicide such as acetic acid or clove oil. These products can be most effective when the perennial weeds are just emerging and the key is to use it every time you see them re-emerging to exhaust their root reserves. This may need to be done several times in the season. I would also encourage you to look ATTRA’s Organic Asparagus Production publication.



Permalink What information can you give me on bamboo production and marketing?


Answer: Thank you for contacting ATTRA about starting a bamboo farm.

Please refer to ATTRA's publication Bamboo, A Multipurpose Agroforestry Crop.

You will find considerable general information about bamboo in this publication. As to your specific questions about species and buyers, these will depend upon your market. Before pursuing this idea further, please consider where you would sell your product. As far as I have been able to determine, there are no manufacturing plants in the US producing either flooring or fiber. All of the processors are in Asia. As for timber bamboo, I believe that the use of bamboo is not allowed by many building codes.

The possibility might exist for selling bamboo sprouts to restaurants. You would need to develop this as a direct sales opportunity.. Bamboo might be used at some paper production plants, if there are any in your area. A final idea would be to sell to nurseries or landscapers. Nevertheless, market research is necessary to determine the demand.

For further research, see the additional resources listed in the ATTRA publication. The American Bamboo Society is a particularly good resource.



Permalink What information can you give me on organic control of pickleworm?


Answer: Thank you for your recent request for information from ATTRA, the National Sustainable Agriculture Information Service regarding organically approved management alternatives for “pickleworm.”

Pickleworm is a tropical insect and is known to invade much of the southeast U.S. each summer. It is a moth that has made cucumber and squash production in many areas of the south prohibitive without extensive chemical use. Although cucumbers are severely damaged some years, squash appears to be the preferred and favorite host. Squash flowers, fruit and small plants become heavily infested while adjacent cucumber flowers and fruit may remain clean.

Cultural Methods:

Resistant varieties of squash are Butternut 23, Summer Crookneck, Early Prolific Straightneck, and Early Yellow Summer Crookneck. The more susceptible varieties are Cozini, Black Zucchini Caserta, Zucchini, Shrot Cofozella and Benning Green Tint Scallop. Many other varieties tested fall between these groups. Tests with insecticides show much better control of pickleworms on resistant varieties than on susceptible varieties. Cucumbers, cantaloupes and watermelons are less frequently and less destructively attacked than squash.

A few plants of a susceptible squash variety are helpful in detecting the first appearance of pickleworms, as evidenced by the insect's presence on flowers. A regional and state pickleworm surveillance program using squash as a trap crop or a sex pheromone trap throughout the Southeast is in various stages of development. You might want to check with you local Extension service to see if they have a similar program in Hawaii.

Biological Control:
Natural enemies such as generalist predators and specific parasitoids have occured elsewhere, but have not reliably suppressed damage (Capinera 2000). In Hawaii, no parasitoids have been discovered for pickleworm, although predators such as lacewings have been observed attacking pickleworm caterpillars.

Biorational Insecticides:

Insecticide applications should begin immediately when pickleworms or their damage appears. Make applications at weekly intervals. More frequent applications may be needed if populations and temperatures are high.

Some organically approved products that are listed on the ATTRA Biorationals Database include:
Neemix 4.5—a botanical pesticide extracted from the Neem tree. The active ingredient is Azadirachtin which is a insect growth regulator. It kills/repels a variety of insect pests including whiteflies, caterpillars, leafminers, aphids, and diamondback moths.
These two active ingredients are derived from the oil found in neem tree seeds. Humans have used this naturally-occurring oil for millennia for medicinal, cosmetic, and pesticidal purposes. When used in pesticide products, both azadirachtin and clarified hydrophobic extract of neem oil can be applied to many food and non-food crops indoors and outdoors to control certain insects and related pests. Adverse effects are not expected to humans, wildlife, or the environment when products containing these active ingredients are used according to label directions. Labels direct users not to contaminate water and not to apply when honeybees are actively visiting flowers in the area. Disrupts insect molting by antagonizing the insect hormone ecdysone; Also serves as feeding deterrent for some insects

Entrust is a biorational pesticide that is OMRI Listed. It is a fermentation-derived insecticide which controls Lepidoptera, Diptera, Thysanoptera, and some Coleoptera. It is available from many organic suppliers, such as Peaceful Valley Supplies and Organic Growers Supply (see below for contact information.)
Condor is a biological insecticide from the Bacillus thuringiensis var. kurstaki for the control of lepidopteran pests. Bacillus thuringiensis delta endotoxins encapsulated in killed Pseudomonas fluorescens control insect larvae on a wide range of crops. Insect larvae vary in how susceptible they are to the many different Bt endotoxin proteins, but Condor is labeled for management of pickleworm.

I also came across some research on using Effective Micro-organisms (EM) to manage pickleworm, although, mind you, the research was done by EM distributors. I have referenced a summary of their research, for you to judge if this would work in your situation.

I always encourage organic growers to employ a combination of treatments to manage particularly pesky pests. This may be necessary with the pickleworm in your tropical climate. Also check with your certifier to insure that these products are allowable under their program. Neemix and Entrust are OMRI certified.

Wood, Matthew, et al. (no date). EM-Fermented Plant Extract and EM5 for Contolling Pickleworm in Organic Cucumbers. Sustainable Community Development, LLC.

Capinera, J. L., 2000. Featured Creatures: Pickleworm. Publication EENY-164. University of Florida, Institute of Food and Agricultural Sciences.

Heu, Ronald, et al. 2005. Pest Advisory Report: Pickleworm. State of Hawaii, Department of Agriculture.

Further Resources:
Peaceful Valley Farm Supply
P.O. Box 2209, 125 Clydesdale Court
Grass Valley, CA 95945
Order Toll Free (888) 784-1722

Organic Growers Supply Catalog
Fedco Seed
PO Box 520
Waterville, ME 04903
(207) 873-7333



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