How to Prune the Dewberry Plant

Wipe your pruning shears free of dirt with a clean cloth. Dampen a cloth with household bleach, rubbing alcohol or a household disinfectant and carefully wipe the blades down before pruning dewberry or other plants. Disinfecting your shears helps prevent the spread of plant disease.

Cut out old dewberry canes down the the surface of the soil as soon as you harvest fruit from them, typically in the spring or early summer. This gives young, fruit-producing canes more room to grow. Allow the young canes -- known as primocanes -- to grow in a mat-like fashion near the ground through the winter. Apply a layer of mulch to protect the young canes during the cold season.

Cut back the young canes in late winter or early spring, before fruiting has begun. On mature dewberry plants, trim each cane down to a height of about 3 to 5 feet. Secure the canes to the trellis, stake or fence by tying them with twine at about 40 inches above the surface of the soil. Remove any injured or broken canes at this time, especially those near the soil's surface. Cut any damaged canes down to ground level.