Smooth Patch is killing my oak trees. - Ask Extension
I have several oak trees on my property that have what looks like smooth patch disease. Your website says that it is not hazardous, but the trees are ...
Knowledgebase
Smooth Patch is killing my oak trees. #872372
Asked June 10, 2024, 10:27 AM EDT
I have several oak trees on my property that have what looks like smooth patch disease. Your website says that it is not hazardous, but the trees are dying. It was first noticed last year, when some outer bark fell off. This spring they did not leaf out. Please advise what I should do.
Olmsted County Minnesota
Expert Response
This is a concern, as several diseases can affect oaks. If they haven't leafed out this year, they may well be dead or dying. What variety of oak are they? Red oaks are more susceptible to oak wilt, although it can affect other varieties. The two-lined chestnut borer has killed many oak trees in Minnesota this year. The trees were harmed by our three-year drought, which made them susceptible to the beetle. I'm attaching a couple of links about oak trees. Read the information and look at the photos to help you determine what is going on with your oaks. If you have several trees, calling in an arborist may be a good idea.
https://www.missouribotanicalgarden.org/Portals/0/Gardening/Gardening%20Help/Visual%20Guides/Oak%20Problems.pdf
https://www.mda.state.mn.us/plants/plantdiseases/suddenoakdeath
https://www.treesaregood.org/findanarborist
https://www.missouribotanicalgarden.org/Portals/0/Gardening/Gardening%20Help/Visual%20Guides/Oak%20Problems.pdf
https://www.mda.state.mn.us/plants/plantdiseases/suddenoakdeath
https://www.treesaregood.org/findanarborist
Attached are a couple of photos that I should have sent the first time. Both of these trees appear to be dead, and they were healthy last year. The second one has some new growth coming out of the trunk, but they don't look like oak leaves. there are other trees nearby that look healthy.
Is this something that needs to be addressed right away or would it be better to wait till fall/winter to take them out?
Don't remove these trees until at least November through March. Even dead oak trees can attract the beetle that causes oak wilt and may result in more infected trees. If you have other oak trees, it would be worthwhile to consult an arborist to determine the exact cause of your trees' decline. By doing that, you may be able to forestall deterioration of any other oak trees.
