Winter hardiness is a major concern of Iowa bramble growers because cold temperatures damage floricanes of blackberry plants. The introduction of primocane-fruiting blackberries helps to alleviate the risk of low temperature injury to the floricanes and extends the blackberry fruiting season into the fall. The objective of this study was to evaluate the fruiting potential of three primocane-fruiting, thorny, blackberry selections grown outdoors in Iowa that were bred at the University of Arkansas by John Clark.