It became difficult to repair plugged emitters and broken lines, and coyotes damaged the lines. Flood irrigation has proved successful, except that weed growth is greater around the plants, and root suckers are proliferating outside the rows. Plants are typically irrigated every one to two weeks with an 4-inch head of irrigation water. Irrigation is critical for first-year blackberries. 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.