Live Oak Tree Diseases

The live oak is a broadleaf, semi-evergreen tree that can reach heights up to 60 feet. This spreading tree has a medium to fast growth rate and can easily reach spreads up to 100 feet. The live oak is a North American native commonly found near the coastal plains. It thrives in sandy, well-drained soils. Like many oak tree variations, the live oak tree is susceptible to several diseases, some of which can be injurious to the oak if left untreated.

Oak Wilt

Oak wilt is a deadly oak tree disease. This fungal disease progresses rapidly on stressed and declining live oak, but it can move just as rapidly in healthy live oak trees. The disease develops on already infected oak and defoliated debris. The infection creates a series of fungal pads around these areas that attract insects and beetles with a secreted odor. The feeding insects carry the disease onto healthy live oak trees, spreading the disease up to 1 mile or more. Infected live oak trees experience foliage wilt and drooping. The veins of the foliage turn yellow and then begin to brown as the leaves die. Dead and dying leaves fall and defoliation continues until the tree dies. The U.S. Department of Agriculture reports that live oak trees infected with oak wilt can die within six months of infection. There is no cure for oak wilt and infected trees should be removed, along with the stump, to prevent further contamination.

Oak Anthracnose

Oak anthracnose is a leaf spot disease that is unsightly but not fatal to the live oak. This fungal disease develops on dead, fallen debris and lies dormant throughout the winter months. The fungal spores move by wind and rain during the spring, and infect newly developing leaves and buds of healthy live oak trees. The infected areas develop brown, dead spots that are pronounced with distinctive margins. The veins of the foliage also experience necrosis. Severely infected foliage will also experience leaf curling, dieback and premature defoliation. Oak anthracnose can be prevented by keeping the tree's area free of debris and maintaining a vigorously growing tree. The disease can also be controlled and prevented with fungicidal treatments that are designed for anthracnose.

Powdery Mildew

Powdery mildew is a common live oak disease that may be injurious, but is not deadly to the tree. This fungal disease travels by fungal spores that form in the late fall and lie dormant throughout the winter periods. This disease requires consistent rains and winds to travel, but needs warm, dry periods to infect and develop. The foliage of infected live oak trees develops tiny fungal spots that appear white to yellowish in color. These spots coalesce to create larger spots that create a powdery mildew coating across the surface of each infected leaf. Infected live oak trees will also experience dieback, growth stunt and premature defoliation from severe infections. The disease can be controlled with a chemical regime of fungicidal spray that is designed for this disease.

Keywords: live oak diseases, oak tree diseases, oak anthracnose

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.