Oak wilt, canker diseases, shoestring root rot, fungal infections and mildew diseases are some of the common diseases that affect southern live oak trees. Some of the diseases are fatal to the trees and can't be treated, while others are not very serious.
Oak wilt is the most common disease affecting southern live oak trees and begins as a paling of the leaves along with a slight crinkling. The disease is fatal, and the recommended treatment is to cut down and destroy the tree. If it is caught soon enough, pruning the affected areas and coating the cuts with prune paint may be effective. Root rot moves up the trunk of the tree and has no practical method of control.
Keeping trees healthy with regular fertilization and pruning affected areas is the standard treatment for canker diseases, fungal infections and mildew cases.