In the past recent years, oak wilt disease has expanded dramatically and can be found throughout Michigan.
What is Oak Wilt Disease?
Oak wilt disease is caused by a fungus that plugs the water-conducting system of oak trees. To block the spread of the fungus, trees produce gums and resins which also plug the system, causing infected trees to die quickly. Oak wilt disease is mainly a problem of red oak trees, which can include the group of northern red oak, black oak and pin oak. These trees will die within just a few weeks of becoming infected. White oaks are more resistant so the disease will progress slower.
How Does the Disease Spread?
Diseased trees pass the fungus to adjacent healthy trees through root grafts. The fungus can also be carried to other areas by sap-feeding beetles, which carry the fungus spores from infected trees to freshly wounded (pruned) healthy trees. The fungus can also be spread in firewood. Infected firewood can form spore-producing pads under the bark which attract sap-feeding beetles. The beetles will feed from those pads and can transfer oak wilt spores to healthy trees, sometimes miles away. Trees become infected when the spores enter fresh wounds in the bark.
How You Can Help Prevent Oak Wilt
If you have plans to trim your oak trees or cut down some limbs, be sure to hold off between April 15th and July 15th, and just to be safe, even after July 15th. Sometimes a tree wound can't be prevented, such as if high winds cause a branch to break. And some cases, wounding a tree is accidental, such as a lawn mower or equipment damaging the bark. Prevention is as easy as being aware of your surroundings to not accidentally damage the tree, and to hold off from pruning between mid-April and mid-July.
Controlling the Spread of Oak Wilt
Controlling the spread of the oak wilt fungus between healthy and infected trees is simple in theory but difficult and expensive in practice. To avoid spreading the fungus, root grafts must be severed between healthy and infected trees. Simply cutting down the tree is not an effective way of stopping the fungus from spreading, because the fungus stays alive in the root system and can spread to healthy trees. Cutting down an infected tree before the root grafts have been severed can actually speed up the movement of the fungus to surrounding trees.
Visit our Tree Removal Service page for a list of local businesses that can help trim and prune or cut down trees.
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