There are many common diseases found in the oak tree. Oak leaf blister, anthracnose, Tubakia leaf spot, bacterial leaf scorch, oak wilt, fusiform rust, powdery mildew, sooty mold, crown galls, hypoxylon cankers, canker or “heart” rot, bacterial wetwood, Armillaria root rot, and just good old fashioned root rot make up the primary offenders to this family of trees that consists of over 600 different types. Over 90 different types grow in North America.
Blistering, scorching, shriveling, the browning yellowing of margins and veins, and premature leaf drop are all common symptoms and signs there is something wrong. These diseases are spread by insects, weather, and ideal conditions depending on the disease.
Understanding what type of oak you have, and the specific infection that is festering will help narrow down treatment and further prevention of spread. Some require simple landscape maintenance while others require additional treatments.