Dont Prune Big Branches in the Heat

Q. My plum tree is 10 years old and I dumbly cut some secondary branches two or three months ago. The tree was infected or inhabited by some bug that had dozens of points with sap dripping for a few years now. It’s lost most of its leaves already. Should I cut and run?

A. You can usually cut small branches from the tree at any time. But if you cut larger branches from the canopy and it opens the tree and the interior limbs to direct sunlight during the summer months you could be in big trouble.

Plums are very sappy trees. they produce alot of sap when injured. Here a limb was cut when the tree was actively growing and it exudes sap as a reaction to being wounded. the sap helps cover the wound and protects it. if bugs like borers are in the damaged area there is a good chance they will be suffocated.

            Never remove major branches from a tree just prior to, or during, the summer months. Larger branches should only be removed in the winter.

            Your plum is not tender to winter cold but if a tree is tender to the low temperatures of our valley there might be freezing damage during the winter. In cases like these you delay pruning until you just start to see new growth coming out in the spring.

Here Pittosporum was cut back and sunburn resulted and dieback of the plant to shaded areas.

            Cutting some branches will not cause the leaves to fall off of the tree unless there were some major problems going on. Make sure that the leaf drop did not just happen for other reasons such as the water was accidentally turned off or the source of water was plugged.

            I would water deeply now with a hose and again in about one week and see what happens over the course of the winter. If the branches are dead, they will snap like a twig. If they are still alive, they will be supple and bend without snapping. If they are supple, then wait and see what happens this next spring.