Growers: High tunnels not just hype


WOOSTER, Ohio – Don’t try to tell the more than 150 people from six states who attended a workshop on high tunnels last week that the idea doesn’t have merit.
Many of them are already using the technology to make big bucks from small acreage, and extending their growing seasons nearly year-round.
And you can bet they’re ready and willing to help allies make the transition from wide open fields to enclosed tunnels.
The concept. High tunnels, also called hoophouses, are on the low end of the greenhouse spectrum, according to Ted Carey, a Kansas State University researcher who spoke at the workshop.
The low input systems are typically plastic sheeting stretched over a metal or plastic frame, either in a dome or A-frame shape, with sides that roll up for ventilation. And for farmers who are willing to take the risk, they’re often homemade.
The shelters protect crops planted directly into the ground inside the tunnels.
“The idea is somewhere between an inverted milk jug over a plant in the garden, and NASA’s growing plants in outer space,” said Otho Wells, a retired University of New Hampshire researcher.
It works. Wells has spent several years testing out the high tunnel concept in New England.
Despite high winds, heavy rains and burying snow, the high tunnels have been successful.
“You need all the light you can get, and a way to ventilate. As long as the house is designed for the weather, it’ll work,” Wells said.
“When the wind starts blowing, you’ll get nervous,” Carey guarantees. “But that’s not to say every time the wind blows, the house will blow away.
“You’ll learn to relax,” the veteran said.
Grower Keith Cramer, who has just finished his farm’s fifth season with high tunnels, calls his tunnels ‘wind magnets,’ and calls his way of dealing with it “management by paranoia.”
“You’ll really find out quick what your structure can do, and then you move on,” he said.
Proof. Vine-ripened tomatoes in May – fresh from northeastern Ohio -aren’t necessarily just a dream, thanks to the high tunnel concept.
Amishman Aaron Weaver transplants Mountain Fresh tomatoes into his Holmes County high tunnels in mid-February, and picks the juicy fruits in May.
Though he admits sometimes struggling to keep the structure warm when wintertime temperatures plunge near zero, a wood stove does the trick on the Weaver farm.
“Those little things you deal with are worth it when you have a product for the market,” he said.
Vigor. Carey’s Kansas research has proven time and time again that plants, whether they’re tomatoes or petunias or black raspberries, will grow more vigorously inside a high tunnel than they will in a field setting.
That means the controlled humidity and temperature inside the house will lead to more compact plants spaced farther apart, fruits that come on in near perfect quality, and less need for fertilizers overall.
Cramer, whose family has been growing produce for three generations, said the crops he grows inside the high tunnel have outperformed the same crops planted outside every year.
And that’s a good enough reason for him to go back to the houses every growing season.
Manage it. There are special management considerations to be made for growers using high tunnels.
For instance, some growers choose to go organic, so precise records must be kept on everything that goes in or out of the tunnel.
For other growers, there are hours of work in a high tunnel to maintain the soil, incorporate compost, irrigate, plant, pick and protect the crops from insects and disease.
Some growers even choose to build high tunnels that are moveable, which can help cut back on disease and insect infestations, the experts say.
The choice to build a permanent or moveable structure affects the entire rest of the system, said Matt Kleinhenz, an Ohio State Extension vegetable specialist.
“Deciding if you’ll move it or not is a big one,” he said.
Marketing. Ultimately, the biggest reason to use high tunnels is to extend the growing season for crops consumers just can’t seem to get enough of.
And that means growers have to feel their way through the market by figuring out what sells the best, not what grows the best, the experts say.
“It usually comes down to the dollar, figuring which one will both perform and sell,” Cramer said.
Crops the growers have found perform well in high tunnels include strawberries, tomatoes, greens and spinach, onions, rhubarb, raspberries and sweet cherries.
(Reporter Andrea Myers welcomes reader feedback by phone at 800-837-3419 or by e-mail at
Related articles:
High tunnel help – Grow, sell your crops year-round, November 17, 2005

Plasticulture opens doors on the farm, Sept. 16, 2004


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