While high tunnel growing is more prevalent in the Northeast and West Coast regions, high tunnel growing is taking place in all regions of the country. Across the Midwest and in the hilly terrain and variable climate of West Virginia, high tunnels are gaining popularity.
Dr. Lewis Jett, commercial horticulture specialist at the West Virginia University Extension Service, began researching high tunnel growing while he was with the University of Missouri Extension. Jett has written extensively about high tunnel growing and has worked with high tunnel start-up and expansion operations in both regions. From strawberries and raspberries to tomatoes and other vegetables, growers are extending the growing season, and doubling and tripling the crops they can grow, using high tunnels.
Intercropping works well in high tunnels.
PHOTO COURTESY OF DR. LEWIS JETT.
"Triple cropping is very feasible within a high tunnel. Since intercropping is widely used, more than three crops is common," Jett said. He noted that tomatoes, which provide a high rate of return, are the dominant crop, followed by salad greens, squash and berries. "High tunnel production will expand in the future," Jett stated. "High tunnels allow for an expanded two months of production on both ends of the calendar for many warm-season crops.
"For many crops, that two-month lead time allows growers to hit the markets when higher prices can be obtained for their crops. With tight margins on all growing operations, and increasing pressures from imports, the extra profit that can be obtained by marketing earlier is essential to profitable operations."
Bret Fahrmeier checks on tomato ripeness.
PHOTO COURTESY OF FAHRMEIER FARMS.
Missouri farm using high tunnels
Missouri is one Midwest state that's seeing an increase in high tunnel growing. Dr. James Quinn, University of Missouri Extension horticulture specialist, noted that classic high tunnels use no electricity. The plastic-covered hoop houses rely on the sun for heat, and air movement is created by raising the sides and through roof or ridge vents.
Bret and Lorin Fahrmeier, Fahrmeier Farms, Lexington, Mo., are using high tunnels to extend the season and improve the quality of their produce. Bret noted that the high tunnels have also helped to increase the farm's income.
There are 2 acres of Haygrove (www.haygrove.com) high tunnels currently in use at the farm, which is located in the Kansas City area. Bret said, "We want to increase our high tunnel growing just as soon as we can afford more."
Fahrmeier's great-grandfather started Fahr- meier Farms as a livestock and row crop operation. His parents also raised livestock and grew row crops until an injury forced them to rethink the operation. Following an initial garden planting and expansion, vegetables became the primary operation, with crops being sold through farmers' markets. After college, Fahrmeier returned home intending to move toward a livestock operation, but instead agreed to help out with the farmers' market sales and was soon immersed in growing vegetables on plastic mulch in the field.
In 2006, they started growing in high tunnels, and the farm now has a 12-bay classic high tunnel that holds about 12,000 tomato plants, with an additional 20,000 field tomatoes planted. The tomatoes are planted from transplants obtained from Neosho Gardens (www.neoshogardens.com), Council Grove, Kan. A Rain-Flo bed shaper is used with a water wheel transplanter to plant the tomatoes, and drip irrigation is used to water the crops. Some common pest issues with spider mites and aphids are managed with traditional products.
High tunnel tomatoes are sold wholesale through a distributor about four to six weeks ahead of field-grown tomatoes.
Fahrmeier notes that his major challenge is finding labor. "We need help in staking the plants and in taking the plastic off," he explained.
Grower sees high tunnels as evolving technology
Jim Wykle, Mountain Top Farm, Renick, ., recalled the evolving technology that has been incorporated on his farm. Initially dryland farming was the norm, followed by irrigated growing and now the move to high tunnel growing. Wykle has grown strawberries in a high tunnel for three years and has recently added tomatoes and broccoli as high tunnel crops, along with companion planting of early lettuce. He sells at an on-farm market and two farmers' markets in Charleston, . He uses drip irrigation with water supplied from an on-farm well and a pond that collects runoff.
Wykle has three tunnels. "I have a Hummert Janes (www.hummert.com) and I'm working on two Puckett (www.puckettgreenhouses.com) tunnels. The high tunnels definitely are season extenders," Wykle said.
Jett noted that high tunnel growing allows production of a high volume of produce without a high number of acres.
High tunnels transfer heat from the air to the soil. "This transfer is most effectively achieved by using mulches that absorb heat, such as black polyethylene," Jett said. He noted that most high tunnels are covered year-round, but in regions with high snowfall, the plastic is removed during the winter.
While classic high tunnels do not have supplemental heat or fans, Jett said, "Adding supplemental heat can have significant advantages for most crops. The marginal costs are low. Minimally heated high tunnels can be even more efficient."
Fahrmeier Farms grows about 12,000 tomato plants in a 12-bay high tunnel.
PHOTO COURTESY OF FAHRMEIER FARMS.
Jett noted that many cropping systems are enhanced by high tunnels. "If a high tunnel is to be most profitable, it should be used for year-round cropping," he said. "Usually a grower can have two crops of a warm-season vegetable and one crop of a cool-season vegetable or fruit within one calendar year." Peppers are excellent rotation crops, and many colored bell and specialty peppers can be grown within a high tunnel. Cucumbers can be grown, and Jett noted that higher success has been obtained in his research with slicing-type cucumbers.
Most warm-season crops are established in high tunnels as early as soil temperatures reach the optimal level, and transplants will reach maturity faster than direct seeding. High tunnel strawberries are ready to harvest approximately five weeks earlier than field-grown strawberries in some locations. However, there can be issues with gray mold and powdery mildew.
"Humidity can be a significant problem within the high tunnel microclimate. Humidity exacerbates diseases and can cause pollination problems on certain crops," Jett explained. "High side walls and ridge vents help."
Assistance is available
The Natural Resources Conservation Service (NRCS) has allocated about $15 million to be distributed across the nation this year to assist with seasonal high tunnel construction. Missouri will receive the highest amount of funding, with nearly $1 million scheduled for that state for the construction of approximately 177 high tunnels.
Quinn and Jett are both members of an organization that shares information about high tunnel growing (www.hightunnels.org) and includes university and extension researchers and specialists, growers and students. The website provides information and resources helpful to both beginning and experienced high tunnel growers.
Nancy Riggs is a freelance writer and frequent contributor. She resides in Mount Zion, Ill.