Be sure to retain those canes with the largest diameter. Black and purple raspberries require summer topping throughout the summer in addition to floricane removal. Do this two to three times during the season to top all of the canes as they grow. For dormant pruning, remove all dead, damaged, and weak canes. Thin remaining canes to 5 to 10 canes per plant.
More vigorous plants can support longer lateral branches.
All canes should be topped to 36 inches if they were not topped earlier. Erect blackberries do not require trellising. They have, as the name suggests, very strong upright canes. Trailing blackberries should be summer tipped at about 6 inches above the highest trellis wire and tied to it during the summer months. For dormant pruning, select five to eight of the strongest canes, remove all laterals originating on the lower 3 feet of the canes, and tip back remaining laterals to 12-18 inches.