The city of Overland Park is asking residents to keep an eye out for a new fungus that has the potential to kill oak trees.
What is it? Called oak wilt, the fungus kills oak trees by clogging their vascular systems and depriving the trees of nutrients and fluid.
- It can spread one of two ways, by either certain kinds of beetles carrying the fungus from tree to tree or by connecting through the root systems of oaks of the same species that are planted up to 50 feet apart.
- City forester Bailey Patterson said oak wilt is a relatively new phenomenon to the Overland Park area, first showing up in the city about two years ago.
- Red oak species, such as pin oak, are particularly susceptible to the disease, Patterson said.
Key quote: “Spreading through root grafts is the biggest concern we have because think of all the streets that are just lined with pin oaks. It can just jump from one tree to the next,” Patterson said. “Usually by the time you’re seeing symptoms on the tree, it’s too late. There’s really nothing you can do to stop it.”
Signs of oak wilt: Homeowners can identify oak wilt by looking at the tops of a a tree’s leaves that will appear brown on the upper-facing side while the underneath layer stays green.
- “There’s usually a very hard line between the brown and the green, which is different from normal stress browning that is usually kind of splotchy,” Patterson said.
- Another sign of oak wilt, she said, is when only sections of the tree, such as a single branch, start turning brown.
- Residents should call a certified arborist if the fungus is suspected in their tree.
Preventative measures: Local experts have offered some measures homeowners can take to prevent oak wilt, including:
- Pruning trees in the late fall or winter when trees are less likely to attract the beetles that spread the disease,
- Storing chopped oak firewood away from other oak trees,
- Sanitizing your pruning equipment before you prune another tree
- and, more longer term, planting other city-approved tree species that are not as susceptible to oak wilt.
Oak wilt in the greater Kansas City area
Patterson said the spread of oak wilt is not just an issue for Overland Park but one that other surrounding cities are also dealing with, including Prairie Village and Mission Hills which have both had confirmed cases, as well.
- According to the Kansas Forest Service, the disease is typically found throughout the eastern and central U.S., and as far south as Texas.
- Oak wilt was first identified in the 1940’s in Wisconsin.
