Blackberries and Raspberries have had their run by the time you’ve made it to the late fall, so it’s time to trim them back in October and early November. These berries bloom and fruit on new growth, and as a vining plant that can grow to be a tangled mess when left alone any Blackberry and Raspberry bush that you depend on for your own fruit needs to be heavily pruned back to maximize the next year’s crop, and to be trained into shape for next year. The key with fruiting plants is to prune them for growth, and shape them into forms that allow for easy harvesting and lots of air circulation in the warm sumer heat. Your goal is to prune and shape your berry bushes so that you can see and access your fruit when it’s ripe, and minimize the spread of powdery mildews, and warm weather diseases that thrive in moist dark areas on your fruit leaves.
How To Prune:
The best way to set yourself up for success next year is to prune your Blackberries and Raspberries back down to the main canes every fall. Trace each one of the berry stems back down to where the plant is sprouting from the ground, this is the main cane. Use a pair of bi-pass Fiskars 7936 PowerGear Pruner shears to make a clean cut, and trim the main cane back to a height of 8-12 inches above the soil line at a 45 degree angle, and remove all of this year’s growth to compost or discard. On the diagram above the proper pruning height is marked as the “first year cane.”
Even if there are no leaves or bud unions on the section of cane that remains after pruning this is the correct height, and will rejuvenate the plant for the following seasons. The canes may also leaf out again from the main cane before going dormant for the winter.
Prepare to shape next years growth on a trellis or up against a fence to support your fresh growth, and secure them into position with twine or string.