Pruning your trees and shrubs is essential to their health but doing it at the wrong time of the year can cause plant stress, stunt growth and prevent blooming. When you should prune depends on the type of tree or bush you’re growing and your goals for the tree or shrub.
Here are some common plants of the Northwest and the best times to prune them:
With flowering trees, you’ll want to time pruning to maximize flowering. Pruning immediately after the blooming season means you won’t miss out on the beautiful flowers and they’ll be better prepared for the following year’s bloom. Many flowering trees in the Northwest bloom in the spring, so generally the best time to prune is around June.
When it comes to fruit trees, the time of year to prune depends on your goals for the trees. Pruning in the winter or “dormant pruning” has a stimulating effect on fruit trees, so if you are trying to maximize the size and fruit output, winter pruning is ideal. Pruning in the winter is also easier because you can see the branches better without the fruit and leaves. If the maximal output isn’t your goal and you are trying to keep your trees on the smaller side, pruning in the summer is preferable as it has a dwarfing effect.
The best time of year to prune blueberry bushes is winter. When the bushes are dormant, it’s easier to see the structure and there’s a greater visual difference between new and old branches. This makes it easier to know where to trim. Pruning in the winter also causes less stress for the bush. After planting blueberry bushes, you should wait about three years before you begin pruning.
Blackberry bushes should be pruned twice a year but using different methods each time. In the early spring, you should tip prune your bushes, which means cutting the canes shorter, to about 24 inches; this causes the canes to branch out, which will lead to more fruit during the growing season. After the growing season, generally around the end of summer or the beginning of fall, you will want to do some clean-up pruning. This involves cutting off the canes that grew berries that year. Canes that have already produced fruit won’t again and pruning them encourages new canes to grow.