Hoop houses aren’t exactly a phenomenon of modern science. They’re merely a cheap version of the conventional greenhouse and have been around for decades.
Yet these simple structures are proving an effective way of growing crops at odd times of the year in an organic environment.
Just ask Lewis Jett. The Missouri vegetable crops specialist is successfully operating eight high tunnels at MU’s Bradford Research and Extension Center several miles east of Columbia.
Growers call them hoop houses because of the shape, but they’re officially called high tunnels, according to Jett, who is also an associate professor of plant science at MU.
Jett has been researching ways to enhance the techniques for using high tunnels for almost three years. It’s part of a four-state project to test how well they work in the Great Plains.
In addition to Jett’s work at MU, researchers at Kansas State and the University of Nebraska-Lincoln are doing high tunnel experiments of their own and working with growers throughout the region.
“They’re well suited for almost any crop you wanna grow,” Jett said. Crops grown in MU’s high tunnels include tomatoes, peppers, cantaloupes, cucumbers, broccoli, kale and basil.
High tunnels are constructed by stretching a clear layer of plastic over plastic frames. Unlike traditional greenhouses, no heating system is needed, and crops are planted in the ground instead of in pots.
Blanket materials are used to trap sunlight for additional heat and vents serve to keep the temperature from getting too warm.
“If it’s 60 degrees outside, it could be in the 90s in here,” Jett said. “We’ve never had a freeze even when it’s 10 below in January.”
Jett said his research is heavily concentrated on growing tomatoes and peppers. By using high tunnels, he’s able to start in March and have produce available by mid-June — nearly a month ahead of crops grown in the field.
During the cold winter months, the research hoop houses become “like huge lettuce factories” producing mostly greens.
Stuppy Greenhouse Manufacturing in Kansas City sells hoop houses in a variety of sizes throughout the United States. Matt Stuppy, vice president of operations, said hoop houses aren’t a cyclical industry driven by new innovations but noted “there’s always been consistent expansion from year to year.”
“I think these professors are trying to find another innovation,” he said.
Stuppy said hoop houses became popular in the 1970s and ’80s because of the development of polyethylene film. Small farmers and horticulturists share part of the market, but Stuppy said nursery growers who use them to protect their crops during the winter are his biggest customers.
An average-sized hoop house for producing vegetables is 100 feet long and 20 or 30 feet wide and costs about $2,500, Jett said.
“One crop of early tomatoes pays for it,” Jett said. “The key is to be the first with produce at the market.”
According to Jett, the structures cost about a fifth of the price of a greenhouse.
He said high tunnels work especially well for organic growers because they protect crops from rain, wind, insects and disease.
Part of Jett’s research involves experimenting with organic composts using tillage and no-till methods. He’s also growing hairy vetch, a cover crop that fixes nitrogen and other nutrients from the air for other plants to use.
“We’re trying to stay one year ahead of growers (in the four-state project) and encounter and solve problems they would have to face,” Jett said.
The only disadvantage Jett sees with high tunnels is the intensive labor involved. He described April and October as the difficult transitional months because you have to adjust the vents three or four times a day to get the right temperature.
“The rest of the time it’s fairly easy,” he said. “Summer it’s open; winter it’s closed.”