When You Have an Outbreak

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With some careful steps you can prevent the oak wilt fungus from spreading.

Credit: Paul Mistretta, USDA, Bugwood.org

If oak wilt has made it to one of your trees, it may find its way to others. You can stop it with these steps.

• Cut roots. The fungus that causes oak wilt travels through neighboring oaks through root grafts. If you have an infected tree, you need to cut its roots off from those of other trees. Use a machine to cut a narrow trench in the ground around the diseased tree. The trench should be at least four feet deep and 100 feet from the infected tree.
• Cut infected trees. The wood must be destroyed. Or, if you want to use the wood, cover it with plastic and bury the edges of the plastic thoroughly so that no beetles can reach the wood. Beetles can spread the fungus to other trees.
• Fungicide. Fungicide will not normally help a tree that already has the disease. But if you want to save trees that are inside the boundary of the trench, which means they may still connected to the diseased tree's roots, you can apply fungicide.

A local extension agent or forester can help you figure out how to control oak wilt in your woods.

You can also take steps to make your trees less susceptible to oak wilt.