Why trimming matters
A good trim does more than make a tree look better. Taking out dead branches keeps them from falling on your roof or your car. Cutting limbs back from the house keeps them off your siding and gutters. And thinning a tree out lets wind move through it, so it's less likely to snap in a storm.
When to trim trees in Ohio
Late winter, while the tree is dormant, is usually the best time for most trees. It's easier to see the branches with the leaves gone, and the tree heals well heading into spring. Oaks are the exception people should know about. In Ohio, it's best not to prune oaks from spring through mid-summer because of oak wilt. Dead or dangerous branches are different. Those should come down whenever you notice them.
Trimming vs. topping
Cutting the top off a tree to make it shorter does more harm than good. It weakens the tree and makes it grow back worse. We trim the right way, so the tree stays healthy.