Why Oak Trees Shed Bark: Natural Growth or Smooth Patch Disease

Seeing bark flakes at the base of your oaks? It's usually one of two harmless causes.

1. Rapid Growth After Good Rainfall

After consecutive wet years, trunks expand faster than the outer bark can stretch, causing it to split and slough off in plates. This is normal and healthy.

2. Smooth Patch Disease

A fungus (Aleurodiscus oakesii) decomposes the outer bark of white oaks, causing it to shed in large pieces. It doesn't harm the living tissue underneath. You'll see smooth, depressed areas on the trunk where bark has fallen.

3. Squirrel Activity (Bonus Cause)

Squirrels sometimes peel bark to access insects or sap, leaving strips on the ground. Look for fresh gnaw marks.

If the canopy is full and the tree looks vigorous, no action is needed. Enjoy the exfoliating bark as a natural feature.