I have a 35 year old apple tree.When should I prune the tree, early spring or late winter?
Thank you for your inquiry.
Whenever you prune you have to remember that trees cannot heal their wounds, not the way we can. Trees wall off damaged parts with a combination of tissue and chemicals to keep decay from spreading further. Every wound is permanent, and pruning inflicts wounds. Pruning cuts made just outside the branch bark ridge and the branch collar supply the tree its best opportunity to compartmentalize the wound.
You can, and should prune dead and injured wood at any time of the year. Dead wood will be dark or brittle, often with the bark falling away. All cuts should be made flush with the parent limb.
Most pruning is done when the trees are dormant, between the time when the leaves drop in late fall and when the buds begin to swell in early spring. The safest and best time to prune your apple tree is just before the buds swell. The most risky time is very late fall and early winter.
The only growth you ever want to prune or remove during the summer months, when the tree is actively growing, is a sucker. Suckers are branches growing from the base of the tree. These branches are never going to bear fruit. They just sap energy from the plant.
You may be interested in this article from McGill University on Pruning of Apple Trees