Oak Apple Galls: Nature's Curious Growths on Oak Trees

What Are Those Strange Balls on Your Oak Sapling?

Spotted weird, round growths hanging from a young oak in Mason Mill Park? They're oak apple galls—fascinating structures caused by a tiny gall wasp. The female lays eggs in a developing leaf bud, and hormones from the eggs trigger the tree to form a spongy mass with a thin, papery shell.

Are They Harmful?

Not at all. The galls don't damage the tree's health. If they're unsightly in your yard, you can simply pick them off. They're a temporary, natural phenomenon that reveals the intricate relationships between insects and plants.