The first growing season, canes from erect blackberries will be semierect or almost trailing. They should be kept in the row area since they will produce fruit the next year. New canes produced in the second and later years will be erect and should be cut to a height of 3 to 4 feet in June to encourage lateral branching. Vigorous plants may require topping two to four times. Prune hedgerows to a width of about 3 to 4 feet.
Blackberry canes are biennial.
Vegetative canes develop the first year, bear fruit the second year, and die after fruiting. Growers sometimes mow plants to ground level immediately after harvest and then dispose of all mowed plant material. Annual mowing for a number of years may weaken the plants. 3-year mowing rotation may prove satisfactory. Rosette or double blossom, a fungal disease, is the most significant factor limiting blackberry production in Mississippi.