February is a good month to prune deciduous trees in many climates. As they are dormant, they suffer less stress from pruning, and there are fewer pests and diseases around at this time of year.

DEAR NEIL: We have moved into a 50-year-old house that has a mature Arizona ash. It’s too wide for where it is. I’m afraid its branches will break in a storm. When can it be pruned? Dear Reader: You ...