Technical Abstract: Western trailing blackberries (Genus Rubus subgenus Rubus Watson) are susceptible to low temperature injury and are not grown commercially in the central or eastern United States. Seven-year-old trailing 'Siskiyou' blackberry plants were trained to the rotating cross-arm (RCA) trellis system. In winter, the cross-arms were held vertically or rotated down to horizontal and either covered with a non-woven floating rowcover or left uncovered. Cane injury was least in plants with lateral canes oriented horizontally and covered in the winter. Cane injury was high in plants with lateral canes oriented vertically in the winter, whether covered or not, and among plants with lateral canes laid close to the ground but not covered. 'Siskiyou' blackberry plants that had lateral canes oriented horizontally and covered with a floating rowcover in the winter produced 250 flower clusters and 6.0 kg.plant-1 compared to 72 flower clusters and 1.7 kg of fruit for plants that were not covered in the winter. Fewer flower clusters were producted on plants with lateral canes oriented vertically. The findings suggested that 'Siskiyou' blackberry can be grown in the eastern United States, where winter injury has frequently caused a crop failure, if the lateral canes are positioned close to the ground and covered with a floating rowcover.