Pruning Mature Ash Tree
What time of the year is best to prune a mature - 40 ft - ash tree? I have been medicating it for the last 10 years and it appears healthy but I want to clear some deadwood on the lower branches. I do not want to attract ash borers to the open cuts.
We don't recommend that you prune from May through September, which is when the emerald ash borer is active. You may prune from October through April, but probably late winter (February or March) is the best time. And please dispose of the wood properly. Read here: