Blackberry and raspberry plants need to be properly prepared for fall and winter. While they appear to be dying back on their own, they still need to be tended to for a successful spring harvest. Follow these three steps in October and November to give your brambles the best chance to survive winter and be ready to produce vigorous fruit in the spring.
Pruning is the act of cutting back plants to send the energy that is being used to grow the plant larger, back down into the bottom of the plant to strengthen the root system. In brambles, there are two different branches to prune.
Primo canes are the branches that originate all of the others—the “tree trunk” of the plant coming from the ground all the way up. The goal in pruning this branch is finding a maximum height for the cane.
In the video above, you’ll see the branch is outgrowing the trellis. Choosing a spot that sits more comfortably on the trellis will help put the plant’s energy into its lateral branches.
The branches extending laterally from the primo canes are the only branches that produce fruit. Keeping these pruned strengthens the plant to produce better fruit. Letting these branches grow wild produces berries smaller in size and quantity.
In all parts of your plants, the dead needs to be cut out. If you doubt whether the branch is dead or not, perform a scratch test. As demonstrated in the video, a scratch test is knifing slightly into the branch. If it is green, there is still life inside the plant. If it is woody and dried up you can be sure the plant is dead.
Take note of the canes and branches moving with the wind. While it may not seem harmful for branches of your brambles to blow with the breeze in the warm fall, it is during winter. Securing the branches will reduce the risk of freezing tips and breaking branches when the wind, snow and ice hit your patch.
In the video, branch locks are used. These are extremely handy for securing branches without putting too much pressure on the plant.
Mulching with wood chips, hay or straw will protect your plants in the winter. The mulch will act as a blanket when freezes come on and also as a moisture barrier. Without the mulch the soil is likely to dry out and erode with the wind.
Taking these precautions now, while the weather is changing, will give your plants a leg up when harsh weather hits. While blackberry and raspberry plants are perennial and survive in most growing zones through the winter, they still need intentional protection.
Threats to consider are wind, floods, droughts, ice storms and heavy lingering snow days. As always, keep monitoring your plants throughout the coming seasons.