Remove any canes that look weak, sick or damaged in March or April for both summer-bearing and fall-bearing plants. Use sharp garden shears to make clean cuts at the base of the damaged canes. Leave the thickest, healthiest canes intact, but prune 1 to 2 inches off their tips. Healthy canes should be spaced about 6 inches apart when your pruning is complete. Throw away the cut canes and tips; do not leave them in the garden or they will attract mold and pests.
Prune your raspberries a second time in late summer, after they stop producing fruit. Remove any canes that produced berries that summer.
Remove the top third of fall-bearing canes after they produce their fall crop. Leave the bottom portion of the cane; it will produce berries the following summer.