Low tunnels are temporary, small (4-8 ft tall, 5-10 ft wide) unheated structures with hoops made of PVC or metal conduit, covered with various materials. While low tunnels afford less winter protection than high tunnels and access is limited after snowfall, they can be erected for $0.50-$1.00 per square foot, estimated to be 5% of the cost of a 4-season greenhouse (Coleman 2009) or 15-30% of the cost of an unheated high tunnel. They are easily moved, simplifying rotation of winter production areas. While many studies have been conducted on the effects of rowcovers during the temperate growing season, there is a lack of information about the effects of low tunnels on temperature during the cold winter months.
Our objective was to determine the winter temperature and light moderating effects of low tunnels constructed of different covering materials. Access the full report for more details.