Once established, blackberries are relatively drought-tolerant, but water stress will negatively affect yield. Mature plants require more frequent, heavier irrigations than do young plants. For mature plants, most recommendations call for about 1 inch of water per week. Keyplex 350 was again applied at 6 ml per plant per year in a similar split application. Pruning and Training Blackberry canes are biennial.
New shoots arise from buds within the crown of the plant.
Small branches grow from the laterals, and bear the flowers and fruits. After harvest, the floricanes die. Meanwhile new primocanes appear during mid-spring. New primocanes will also arise from buds on the roots, and often these shoots are called root suckers. Suckers should be allowed to grow if they develop in a row as much as two feet wide.