Diseases on Oak Trees

The oak tree is a broad-leaved, deciduous member of the Beech family. These hardy and tolerant trees can grow more than 100 feet tall with a spread as expansive as its height. With a lifespan potential that can exceed 200 years, mature trees can draw and use more than 50 gallons of water a day. Though oak trees are sturdy and resilient ones, these trees are susceptible to certain diseases, some of which can be fatal.

Oak Leaf Blister

Oak leaf blister is a common oak disease that develops during the cool, wet periods of spring. Red oak trees are especially susceptible to this fungal disease. Infected oak trees will begin to display symptoms of infection in the early summer. The infected foliage will develop yellow, blister-like spots which will darken and deaden with age. Severely infected leaves will curl. Oak leaf blister does not cause permanent injury to the tree but will distort its appearance. The disease can be treated with a single fungicidal spray treatment applied in the early spring just before bud break.

Sudden Oak Death

Sudden oak death is fungal disease that can be fatal. Oaks that are infected with this disease develop bleeding stem cankers, leaf spot and twig dieback. Infected trees may also experience bark necrosis. Vigorous growing oak trees may thrive for several seasons before being ravished by the disease. Once the disease overpowers the tree, the crown of the tree will change from green foliage to a yellowish-brown, wilting foliage in several days. There is no cure or fungicidal treatment to control or reverse the effects of the disease.

Oak Anthracnose

Oak anthracnose is a fungal disease that results in leaf blight. This disease, like many fungal diseases, germinates during periods of warm, wet weather with moist soils. These fungal spores lie dormant on defoliate debris around the tree. Once the wet temperatures occur, the fungal spores infect the foliage of the tree, targeting the young, newly developed foliage first. The infected leaves initially display small, brown spots near the veins. The progression of the disease causes the infected areas to widen and deadens the foliage. Severely infected foliage will curl and defoliate for the tree. Symptoms of oak anthracnose are generally more severe toward the bottom of the tree and lower crown. Infected areas should be pruned and discarded. A series of fungicidal treatments, beginning before bud break, will assist in controlling the disease.

Keywords: oak anthracnose, oak leaf blister, sudden oak death, oak tree diseases

About this Author

Charmayne Smith is a business professional and freelance writer. She has worked in management for successful organizations since 1994. Smith draws on her business background to write articles, and her work has appeared in a variety of online outlets. She holds a degree in business from Cleveland State University.