Blackberry Thornless Evergreen A thornless specimen; the Blackberry Thornless Evergreen finds it easy to harvest fruits, and produces large yields of berries each August. In Summer; white flowers develop on this hardy shrub, sprinkling its evergreen foliage with the promise of what’s to come. As the fruits of this Rubus appear, they turn from green to red, and then to glossy-black, looking plump; signaling the time has come for these berries to be picked. Height and Spread: 300cm (118”).