How to Prune a Coral Bark Maple
Q: I have a coral bark Japanese maple planted five years ago. I have not cut anything other than the “wild hairs” that have escaped the mass of branches. When and how do I trim the maple’s interior branches?
A: Young Japanese maples are prone to put on lots of exuberant “whips”: skinny branches covered with leaves. If you prune them, you’ll get lots of thin twigs at the ends, making the interior dark. Generally it’s better to leave the whips alone. They look a lot better after a few years.
Winter is a good time to prune because you can see the branch structure. First, remove branches that go straight up, cutting each at the base.
Stand back a minute and note which of the remaining branches can be taken out to give the tree an open appearance, such that “a bird could fly through it”. You may need to prune off a couple of lower branches to give more light underneath.
Avoid removing more than 30% of the total limbs on the tree.