When to prune? I get this question regularly. Is it OK to prune my Shumard oak now? Can I reduce the size of my photinia at time of year? My azaleas have grown too large this summer; can I cut them back? Is it okay to cut my crape myrtles back in the fall?
There are a couple of hints that will help you make these decisions.
Prune spring flowering shrubs right after they bloom. Azaleas, forsythia, quince and lilacs are spring flowering shrubs.
Prune summer flowering shrubs right before they start to grow in the spring. Crapes and rose-of-sharon are a summer flowering shrubs.
Prune roses in the spring. They often will start growing before it is a good time to prune.
Evergreens can be lightly pruned at the end of the summer. Evergreens should be more heavily pruned right before growth in the spring.
Don't paint the pruning wound. There is no good reason to use pruning paint in our area. An exception is roses. Use a little white glue on the cut ends of the cane. This can help keep the rose cane borer from becoming a problem.
Fall isn't a very good time to prune trees. Our deciduous trees, trees that lose their leaves, are pulling nutrients out of their leaves and storing it for the spring flush of growth. Most of our trees perform better if we prune them while they are dormant. Our main dormant time is during the winter. After the leaves fall from the trees we can prune with confidence. For some species such as silver maples, that re-sprout vigorously, the summer dormancy is actually preferable. Summer dormancy happens when the trees have shut down because of the heat and/or drought. Pruning in the summer keeps the plant from re-sprouting as vigorously.