Grow Rubus 'Black Satin' when you want a thornless blackberry that is easy to harvest and highly productive in the home garden. You will get vigorous, semi-erect canes that benefit from support, plus clusters of white spring flowers followed by glossy, deep-black berries in summer. Mature canes typically reach about 60-84 inches tall; spacing and training will influence the overall footprint. Plant where you can comfortably pick and prune, and where you have room to tie canes to a trellis or sturdy wires.
For best results, give it full sun for the heaviest crops, though it will tolerate part shade. Choose well-drained soil enriched with compost, and keep the root zone evenly moist during establishment and fruit fill. A 2-4 inch mulch layer helps conserve moisture and reduces weeds, but keep mulch a few inches away from the crown to discourage rot. Feed lightly in spring if growth is weak, and avoid excess nitrogen that can push lush canes at the expense of fruit quality.
Like most blackberries, this is a floricane-fruiting type: canes grow the first year and fruit the second. After harvest, cut the canes that fruited down to the ground and remove them from the trellis. Select several strong new canes to keep, tie them in, and tip-prune as needed to encourage laterals and keep the planting tidy. In colder areas, provide winter protection for canes by mulching the crown and, where practical, laying canes down and covering them. Water during dry spells, especially while berries are sizing, for plumper fruit and better flavor.