High tunnels may help mitigate climate conditions and inclement weather threats to lettuce (Lactuca sativa L.) production yet there is a lack of information for the Southeast region. This study evaluated the effect of high tunnels, planting dates and cultivar selection on spring, organic lettuce. A greater marketable fresh weight for both butterhead and romaine lettuce was observed under high tunnels compared to the field in 2016 but not in 2015, indicating the advantage may depend on yearly weather conditions. Both years, the high tunnel lettuce was harvested 5 to 10 days earlier than the field. The greatest micro-environmental differences between the high tunnels and field included: air temperature on cold days, leaf wetness, and photosynthetically active radiation. Pests, diseases and physiological disorders were not different between the two systems. The butterhead cultivar Sylvesta and the romaine cultivar Green Forest consistently performed well in both systems.
