Thornless Blackberry Cultivars Grown
with a Rotatable Cross-Arm Trellis System
Blackberries (Rubus L.) are a potential berry crop to diversify Iowa’s agricultural enterprises if plant injury caused by low temperatures is avoided. Winter temperatures below -13°F damage current commercial blackberry cultivars. Systems that improve winter survival of less-winter hardy, thornless blackberries have been used in other locations of eastern United States. The systems include using a rotating-arm trellis to lay blackberry canes near the soil surface to overwinter them under a row cover for protection. The rotatable arm trellis growing system also enhances management practices, such as pruning and training, harvesting, pest management, and proper air and sunlight penetration in the blackberry canopy during the growing season.