Oak Leaf Blister: Identifying Characteristics
| Identifying the disease: | Leaf blisters first appear on the underside of leaves as small, slightly depressed gray areas. Over time the infection causes the leaf to become deformed, forming a blister. The blisters can grow to be 1/3" or larger and can be seen on both sides of the leaf. Mature blisters are gray or brown in color. There may be several blisters on a leaf and if blisters occur near the edge, leaf curl may result. Oak leaf blister is not usually noticed until many leaves have become very blistered or excessive leaf fall occurs. |
| Susceptible trees: | Any oak can be infected. Live oak, water oaks, and laurel oak are preferred hosts. |