Rinse berry vines off with a garden hose two days before you plan to prune. Rinsing eliminates, dust and spider webs and encourages pests to leave the area.
Put on a long-sleeved shirt and leather gloves. Black raspberry vines have sharp thorns of two varieties: tiny thorns on new growth that enter the skin like splinters, and thorns on older canes that are akin to the rigid thorns found on rose bushes.
Cut off all canes that produced fruit in the current season at ground level.
Tie new canes to a trellis with twine to encourage their stability prior to the next growing season. Cut them down to 12 inches if you do not have a trellis in place.
Cut trimmed vines into ten-inch sections and carefully discard them in your rigid trashcan. The thorns on black raspberry vines will slice through plastic garbage bags