Proper Tree Care May Prevent Oak Tree Threat

October 24, 2019 | Tree & Shrub Care | Kylie Kelty

The Farison Lawn
Care Guarantee

Trees are an essential part of our life. They provide oxygen, shade, and add beauty to our landscapes. But proper tree care is needed to ensure your trees are strong, healthy, and thrive. 

When I think of the patriarch of trees, immediately, the oak tree comes to mind. It’s large stoutly trunk, and strong, powerful branches house mass quantities of round-shaped leaves. Oak trees are tall, elegant, and proud, but there is an invasive disease raging through parts of the U.S, including Kentucky. The disease, called oak wilt, is deadly and exhausting the life out of them taking away the very essence that makes them so powerful and resistant.  

What is Oak Wilt?

Oak Wilt, Ceratocystis fagacearum, is a fungal disease that moves through the vascular system of the tree, cutting off its supply of water and nutrients. The lack of nutrients and water causes leaf discoloration, wilting of the tree, and the leaves to fall off, ultimately leading to death. 


Oak trees are divided into two groups, red and white oaks. Red oaks, which consists of pin oak, black oak and northern red oak are more susceptible and usually die within a few weeks of infection. White oaks are more resistant and may live for several years. The symptoms are different on each. On red oak, the first sign of oak wilt is a brown discoloration of the leaves around the top of the tree. Leaves may be brown, or partially green. Whole branches may start yellowing and browning as the disease progresses. Leaves begin to litter the ground as the tree begins to wilt. As the fungus grows, it causes the tree bark to crack. At this point, you may see various patches of dark brown splotches and white patches on your tree bark. 

How Oak Wilt is Spread

  • Underground Transmission – This is when the roots beneath an infected tree intermingle with the roots of an unaffected tree. The infected trees’ roots send out shock waves through its root system, spreading the disease to all oak trees around it. The only time a tree is not susceptible is when it is completely dormant. 
  • Overland Transmission – If an infected tree is pruned during active growth, it permeates an odor similar to stale beer. The odor attracts Nitidulids (commonly called sap beetles). Sap beetles feed off the fungus on top of the bark, and the fungal spores stick to their bodies. As the sap beetles fly from tree to tree they infect other trees in their wake. 
  • Moving firewood – Fungus forms on wood cut from infected oaks, providing new sources of infection. 


You can help to prevent oak wilt by only pruning your oak tree during the winter months. Pruning should only be done between November and the end of March. Pruning during the winter will give the tree time to heal before the fungus is able to attract sap beetles. If you have to cut any limbs or branches, and the temperatures are seasonably warm, make sure all wounds are sealed with a tree wound dressing or latex paint. Remember, when pruning any tree, it is essential to clean your tools with alcohol or bleach between cuts properly.  

Another way to help prevent the spread of oak wilt is by not moving firewood. 

What to Do if Your Tree Has Oak Wilt

A correct diagnosis is critical to reducing the spread of the disease. The only way to cure oak wilt is through the elimination of the tree. Because underground transmission can infect other trees, it’s important to sever root connections between infected and healthy oaks. Oak wilt can often be confused with other tree-related diseases, and it is best to have a professional come out and inspect the tree. 

Farison Lawn Care Provides Tree and Shrub Care and can help keep your trees strong and healthy.  We will conduct a free tree and shrub inspection by one of our experienced staff to uncover any damages or risks to your trees and shrubs. We can then devise a fertilization plan that may include annual deep root fertilization. Our Tree and Shrub Care Program Includes:

  • Free Tree and Shrub Inspection
  • Tree and Shrub Deep Root Fertilization
  • Disease Control
  • Insect Control
  • Dormant Oil Treatments

Feel free to contact us to learn more about our Tree and Shrub Care program and how we can help ensure your trees and shrubs live long, prosperous lives. Call 502-245-9422 or fill our contact form now.

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