Japanese Maple owners want to know if they can prune a little of this spring's bumper crop of new growth. Of course!
Light pruning of pencil size branches rarely damages a tree. If new growth is snipped so that it no longer bends under its own weight, a tree will look much more dignified.
Getting carried away can create serious problems though. Foliage is the tree's sunscreen and protects the bark from burning. It's preferable to have a tree with a bad hair day [or hair month] than a tree with scorched bark.
Tree Pruning by Studio Wildwood.