Common Diseases of Black Oak Trees

The black oak tree thrives in dry, rocky mountainous regions in the Eastern and Central United States. In the Appalachian Mountains, the black oak grows 4,000 feet above sea level. The tree is also known as the yellow bark oak for its yellow underbark, which was used to tan leather and as a dye. The black oak is susceptible to oak wilt, shoestring root rot and oak anthracnose.

Oak Wilt

Black oaks throughout the Eastern United States are highly susceptible to oak wilt, a fungus that can kill already stressed trees. The fungus enters the tree through cuts in the bark, multiplying rapidly in the sapwood and destroying the tree's conductive tissue. The symptoms begin with curling leaves, then progress to leaves yellowing at the edges and then overall leaf dieback, according to "Pests and Disease" by Richard H. Cravens. The disease is spread through the roots and by bugs that move from tree to tree, feeding on the sap. To treat, remove and burn affected trees.

Shoestring Root Rot

Black oaks are also affected by shoestring root rot, a fungus. First the leaves become discolored, turning either yellow or brown. Then, they stop growing and finally fall prematurely from the tree. A white fungus will appear between the bark and the heartwood of the tree, and black, thin strands of fungus will appear in the soil at the base of the trunk. In some cases, mushrooms will grow around the trunk, according to Washington State University Cooperative Extension. Destroy diseased trees including the stump and roots to avoid spreading the disease. Disinfect all tools used in the excavation.

Oak Anthracnose

Oak anthracnose is a fungal disease that causes irregularly shaped leaf spots to appear on the leaves of the black oak. In young leaves, the leaf tissue dies and holes are left along with the spots. The disease is most apparent on the black oak's lower inside branches, according to Dan Gillman with the University of Minnesota Extension. The fungus is caused by too much moisture. The disease is not fatal to healthy trees, and prevention is key to controlling oak anthracnose. Do not overwater the trees. Prune trees during dry weather only. Fertilize trees in the spring. Use a fungicide on trees that have outbreaks of anthracnose year after year.

Keywords: black oak diseases, oak tree diseases, disease of oaks

About this Author

Caroline Fritz has more than 18 years of writing and editing experience, mainly for publications in Northwest Ohio. She is currently an editor for a national technical magazine focusing on the construction industry. She has a Bachelor of Science in journalism from Bowling Green State University in Bowling Green, Ohio.