When I first started growing boysenberries and all those bramble type fruits I had a real problem determining what I should be pruning out and what I should be leaving. It sounds quite simple until you stand in front of that tangled mess that your Boysenberry has become and wonder where to start…. To make the winter prune a little easier I started tidying up the berries in the summer.
During the summer months my berries grow really strongly and the new canes (that aren’t going to fruit until next year) grow rather out of control. These new canes only need to be as long as you can easily manage. Once they have grown 2-3m long I stop mine by cutting off the ends otherwise they continue to grow all over the ground and through your plant and mask the berries that are ready to pick and attack me every chance they get. I keep only as many as I want for the next year. If you have too many cut these off at ground level too. I find that no one wants to help pick the berries if they are going to be ripped to shreds and the easier I make the access to the plump ripe berries the more help I get.
Boysenberries, Blackberries, Tayberries, Karakaberries, Boysenberry Brulee, Thornless Jewels etc can all be treated the same way. All the canes will fruit only once. Therefore when winter or late autumn comes and you are ready to attack your berries – anything that has an old seed/fruit heads on it should be cut away at ground level and you can then tidy up your new canes that you “stopped” in the summer. By now these will have produced smaller side branches. Trim these back to a short knobby shoot and it is from here that your berries will be produced in summer. Your berry should look a little like the one in the picture above which is a Thornless Jewel – a Jewel to eat and a Jewel to prune and it is thornless too!
Once you have pruned your berries clean up any old leaves from the ground and give them a clean up spray with Liquid Copper. If your berries have suffered with insects of any kind over the summer and these are still lingering be sure to give them a spray with something appropriate. You don’t want these to become active in the spring and it’s so easy to kill them now while your canes are leafless.
