It's time to finish pruning last year's raspberry canes before new growth begins. The fall types that bear in August on first year canes are pruned to the ground every year in late winter.
Based on information from Cornell University, the best time to prune is from December through early March. Before December, the plant is still moving energy from plant leaves to the crown and pruning canes removes valuable carbohydrates. After early March, carbohydrates have already moved from the crown to buds that may be removed in pruning.
Prune canes as close to the ground as possible so that buds break from below the soil surface. If you leave a stub, buds break on the stub and resulting canes are poorly anchored and subject to breaking in winds. In the photo right, two canes near the head of the pruning shears have been correctly pruned at ground level. The four inch stub at the right of the photo should be pruned again closer to the ground.
Gather all pruned canes, rake fallen leaves and remove all plant materials from the site. This eliminates overwintering aphids and other insect and disease organisms.
While the single crop produced by the fall bearing type raspberries is smaller than traditional summer bearing types that bear fruit over two years, management is much easier. Rather than pruning the two year canes of summer types after bearing in late summer from among new, one year canes, all canes of fall types are easily pruned to the ground in late winter. Eliminating detailed pruning is only one advantage of fall types. Also eliminated are cane thinning, support and tying, cold injury of buds on overwintering canes, overwintering insects and damage from rabbits or voles. For all these reasons the fall bearing type raspberries are recommended.
For more information on growing raspberries and other small fruit, attend one of my classes (see schedule right column).
Photo credit: Pruned raspberry canes, Closeup of pruned canes, Disposal of raspberry prunings - All credit Carl Wilson