AMES, Iowa – High tunnels are inexpensive, passive solar structures that are designed to extend the growing season and intensify production. While relatively new to agriculture in the United States, high tunnels can increase profits for producers when properly managed.
To help producers understand how to use a high tunnel and what crops can be profitable in it, Iowa State University Extension and Outreach has released the “Iowa High Tunnel Fruit and Vegetable Production Manual” (HORT 3060), a 17-chapter guide to its use.
“We wanted the information to be very specific to high tunnels and there really wasn’t anything else out there that we thought was good enough,” said Joe Hannan, commercial horticulture specialist with ISU Extension and Outreach. “We also tried to make the information as easy to read and understand as possible, especially with the wealth of new research into high tunnel production.”
Chapters in the manual are written by ISU Extension and Outreach specialists Hannan, Linda Naeve, value added ag specialist; Lina Rodriguez-Salamanca and Laura Iles, Plant and Insect Diagnostic Clinic; Ajay Nair, commercial horticulture specialist; Craig Chase, local foods program manager, and Patrick O’Malley, horticulture specialist.
“Having authors from so many areas within ISU Extension and Outreach was a priority right from the start,” Hannan said. “We wanted the book to be all-inclusive, and the production side is only one part of growing in a high tunnel. We wanted to have a full discussion of economic issues, how to properly put up a building, controlling pests and marketing crops.”
The manual also discusses in great depth which crops should be grown in a high tunnel. Each chapter covers not only how to grow that crop, but what levels of production are needed for it to be profitable.
“For many people, this is their first foray into growing fruits and vegetables so they don’t have a background knowledge of what is profitable, especially if they are coming from gardening for home consumption where profitability isn’t something they think about,” Hannan said.
Deciding what crops to plant, as well as when and how often, can make the difference between making and losing money when using a high tunnel.
“If you want to make money and pay for building the high tunnel then you have to plant something that will generate revenue or brings in extra value,” Hannan said. “No matter what, profitability has to be the number one driving factor for decisions.”
Leafy greens, tomatoes, peppers and cucumbers are discussed in detail in the manual, and are some of the crops that provide the most value in a high tunnel. Chapters on site selection, plant disease and insect management, irrigation, soil management and cover crops are also included.
Information on how to best manage the challenges presented in a high tunnel are presented as well.
“There are different challenges inside a high tunnel compared to a field and it is much easier to proactively manage these issues right away than to wait for a disaster to occur and try to fix it then,” Hannan said.
Funding for the Iowa High Tunnel Fruit and Vegetable Production Manual was made possible by the Iowa Fruit and Vegetable Growers Association and ISU Extension and Outreach.