Q: I don't know what this is on my oak tree, but is it anything I should be concerned about (see reader's photo)? Should I spray with something? A: Unfortunately, I suspect your tree has hypoxylon ...

Waiting until the leaves drop in fall is a rule of thumb for pruning shade trees, mainly because you can see bare limbs better, and the job is less “messy” without leaves attached to the cut branches.

When the branches of your trees and shrubs are bare in winter, you have an opportunity to spot cankers that might be hidden by leaves in summer. A canker is an area of disease in the wood of a plant. ...