FARM SCIENCE REVIEW: Hydroponically, Ohio not yet mature


LONDON, Ohio – Vegetable growing is moving indoors, and a federal grant program in northwest Ohio has developed a unique resource to assist people who are interested in hydroponic vegetable growing.

Mary Donnell, OSU Extension commercial horticulture agent at the OSU Agricultural Business Enhancement Center in Bowling Green, Ohio, was at Farm Science Review Sept. 19 to talk with hydroponic growers and to present a program for the public on “Growing Hydroponic Vegetables in Ohio.”

While hydroponic growing of vegetable crops is an ancient industry, going back centuries in Europe, Donnell said it is not a huge business in this country, which has relied more on field growing of vegetables – usually shipped long distances.

But Canada has thousands of acres of hydroponic greenhouses, and it is becoming a major industry in Mexico as well.

Once larger. Ohio used to have more indoor greenhouse vegetable production, but most major growers switched to bedding plants to avoid some of the greenhouse problems associated with maintaining the kind of year-round growing conditions vegetables require.

But Ohio has a well established greenhouse industry, and there is a growing interest in hydroponic production.

Right now Ohio is home to 42 hydroponic greenhouses that total 19 acres of indoor floor space for vegetable production.

The industry totals about $5 million a year in economic activity.

The largest of these greenhouses is 31/2 acres. Most are one- or two-bay greenhouses.

Tomatoes big crop. Tomatoes is the most common hydroponic crop, Donnell said, but it is also the most competitive.

Ontario, which has the largest hydroponic industry in Canada, already exports 80 percent of its greenhouse tomato crop into the United States.

There is also a growing interest in specialty lettuce, which, when grown hydroponically, can be packaged as a “living plant” with the root, to give it a much longer shelf life.

And Ted Short, professor of biological engineering at the Ohio Agricultural Research and Development Center in Wooster, has been looking into new technologies for the production of other hydroponic vegetables, including cucumbers.

Peppers is another major hydroponic crop in the Canadian industry, but up to this point is not being grown in a greenhouse by anyone in Ohio.

Not just water. Hydroponic production does not necessarily mean grown in buckets of water, as many people believe. It means grown without soil, and the kind of greenhouse structure and growing material used for each crop is quite unique.

Tomatoes are usually grown in vermiculite, are grown vertically, and have to be tended, trained, and controlled since they are not genetically determined to stop when the plants reach a certain height. Since tomato plants are heavy, the greenhouse has to be tall and structurally reinforced.

Cucumbers, on the other hand, are grown in spun rock fiber or buckets of pumice and will usually stop growing when they reach the end of the trellis.

Lettuce is grown horizontally in troughs with roots coming through the holes in the trough to absorb nutrient, but not rooted in any material.

With some crops, bees need to be kept in the green house for fertilization. With other crops, like lettuce, each plant comes from seed.

Computer controlled. Heating, air conditioning, and natural ventilation are a constant in any hydroponic greenhouse, as is a computer-controlled environment.

Although the project that Donnell heads is housed out of the Bowling Green facility that serves an eight-county area in northwest Ohio, she said the bank of information she has developed is being used by growers across the state, and through her Web site,, far beyond the state’s borders.

“There is nothing else quite like our program available,” she said, “and I get requests for information and assistance from around the world.”

She has even been in touch with the greenhouse gardener at the U.S. station in Antarctica.

The program is geared to provide both business and horticulture assistance. It can help potential growers determine what their costs will be, what kind of greenhouse they will need, what kind of heating system they should consider.

OSU offers help in determining and developing markets, and do provide some direct assistance in marketing product to produce buyers.

Study group. The center has formed a hydroponic study group for active growers, some of whom drive more than 150 miles to attend the meetings.

The advantage of greenhouse production, Donnell said, is that vegetable crops can be grown in a much smaller area and with minimum pesticide usage. The plants generally have a much higher yield than plants growing outdoors in soil. And they can provide a local source of fresh vegetables all year.

High-value crops. Greenhouse operations in Ohio are mostly marketing locally. The best markets are in high-value crops that can be sold to restaurants and local stores.

A couple who came to Farm Science Review from southern Ohio were seeking information on growing heritage vegetables in a greenhouse, Donnell said.

“Although the disease susceptibility makes such a venture seem a high risk,” Donnell said, “they are trying it on a very small basis. If they succeed, there would be an unlimited market for the green and yellow striped tomatoes. Restaurants would love to have them.”

And, she said, she gets inquiries every week from people who would like to start a new greenhouse business. Many are farmers looking for a way to supplement their farm income.

What the program can do, Donnell said, is help them make an informed decision with solid information on whether or not it would be a good business decision.

And for everyone who does want to try, she said, the best advice is to start small.


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