Monday, July 02, 2012Oak wilt is a lethal fungal disease that plugs the water conducting system in an oak tree. It can occur in all species of oak, but will very quickly kill red oaks.
Prompt diagnosis is crucial. The primary symptom is wilting of the leaves and early defoliation. In the red oak group wilting generally progresses from the top of the canopy downward. In white & bur oaks, wilting may occur on branches scattered throughout the tree. These symptoms may also be cause by anthracnose, bur oak blight or two-lined chestnut borer. Laboratory testing may be needed to confirm oak wilt.
The disease may be spread by picnic beetles attracted to fresh wounds, but occurs primarily through root grafts between trees.
Do not prune oaks during the growing season. Quickly repair storm damage and paint any wounds that occur during the growing season to avoid insect transmission.
Control includes these important aspects:
- 1. Trenching 5ft deep to severe root grafts between infected and healthy trees
- 2. Fungicide injections of asymptomatic trees within transmission distance
- 3. Sanitation -Remove infected trees after trenching and before the next growing season
Do not leave wood on site w/o de-barking or completely sealing
If you suspect you or a neighboring property has oak wilt, contact your Certified Arborist at Wachtel Tree Science for diagnosis and management plans.