High tunnels are unheated greenhouses that can help commercial farmers extend their growing season in order to improve the profitability and productivity of their farms.
High tunnels are also an integral part of local food production systems in many parts of the United States. They aid fruit and vegetable crop production by extending the cropping season, providing protection from the elements (wind, storms, heat, etc.), and result in a more-stable production system that poses less risk of crop failure (hightunnels.org).
For more information about high tunnel construction, use, and Jacobsen lab research at UK, please watch these videos: