Question
I am new to my home that has a neglected aspen tree in the yard. when we moved in it was almost totally dry with few green leaves left after a hot spell we had here. My question is when can I trim some of the most dry branches or trim it to a more appealing look?

Answer
It can be done now. Aspens tend to bleed if done in the winter or early spring. Pruning cuts should be made just outside the branch collar. The branch collar contains trunk or parent branch tissue and should not be damaged or removed. If trunk collar has grown out on a dead limb to be removed, make the cut just beyond the collar. Do not cut the collar.

If a large limb is to be removed, its weight should first be reduced. This is done by making an undercut about 12-18 inches from the limb's point of attachment. A second cut is made from the top, directly above or a few inches further out on the limb. This removes the limb leaving the 12-18 inch stub. The stub is removed by cutting back to the branch collar. This technique reduces the possibility of tearing the bark.

Dead branches that have a collar of live wood should be cut just beyond the outer edge of the collar.
Do not use pruning wound paint this will slow down the healing process.