Oak Leaf Blister
Article at the Pinellas County Extension entitled “Oak Leaf Blister” by Theresa Badurek, Urban Horticulture Extension Agent:
It’s that time of year again, the leaves are green, the flowers are blooming, the birds are singing, the oak leaves are blistering. Ah spring! Wait a minute‐ oak leaves blistering? Yes, this is a common sight in the spring. Oak leaf blister (Taphrina caerulescens) is a common fungal leaf disease on oaks in Florida. It can affect any oak, but it seems more prevalent on laurel oak. This is a fungal disease that is more prominent after cool wet weather.
The spores of this fungus infect newer leaves and cause the swollen g blister‐like tissue you see below: