Oak Wilt - Ask Extension
Hello, I noticed my oak tree began dropping many leaves a couple of days ago. Initially, I did not think anything of it as I know that is not necessar...
Knowledgebase
Oak Wilt #873906
Asked June 20, 2024, 10:58 AM EDT
Hello, I noticed my oak tree began dropping many leaves a couple of days ago. Initially, I did not think anything of it as I know that is not necessarily uncommon in excessive heat. However, when looking at my tree, I noticed my neighbor had 3 trees that were dead or dying it would appear. Obviously, I am now concerned with oak wilt. I attached photos below but the tree is massive and I am it's difficult to see that high up in photos.
Muskegon County Michigan
Expert Response
Hello,
The first thing you need to do is collect a sample to send into MSU Plant Diagnostic lab. You really do need to get a lab test to determine whether or not this is truly oak wilt, because if it is, it needs to be handled properly to prevent a larger spread. (Or more correctly, to stop the current spread.) The nearest branch to collect a sample looks pretty far away, so you might need to get an arborist to get the sample. Here is how to collect a sample properly for most accurate results: https://www.canr.msu.edu/news/the-best-sampling-procedures-for-accurate-oak-wilt-testing
If you do need to get an arborist, I recommend getting an oak wilt qualified specialist- a list of these specially certified arborists is here: https://www.michiganoakwilt.org/oak-wilt-qualified-vendor-directory
As you may already know, this disease can be spread to healthy oaks nearby through the root systems. You may be able to prevent some of the other oaks on your property from becoming infected by treating them with a fungicide called propiconazole. This needs to be injected into the tree by a professional but is effective if properly done. Until you know whether you are dealing with oak wilt for sure, you cannot really do anything.
Read more about oak wilt here: https://www.canr.msu.edu/resources/smart-gardening-to-prevent-oak-wilt
I would recommend acting on this quickly.
Thank you for contacting Ask Extension.
Ruth
The first thing you need to do is collect a sample to send into MSU Plant Diagnostic lab. You really do need to get a lab test to determine whether or not this is truly oak wilt, because if it is, it needs to be handled properly to prevent a larger spread. (Or more correctly, to stop the current spread.) The nearest branch to collect a sample looks pretty far away, so you might need to get an arborist to get the sample. Here is how to collect a sample properly for most accurate results: https://www.canr.msu.edu/news/the-best-sampling-procedures-for-accurate-oak-wilt-testing
If you do need to get an arborist, I recommend getting an oak wilt qualified specialist- a list of these specially certified arborists is here: https://www.michiganoakwilt.org/oak-wilt-qualified-vendor-directory
As you may already know, this disease can be spread to healthy oaks nearby through the root systems. You may be able to prevent some of the other oaks on your property from becoming infected by treating them with a fungicide called propiconazole. This needs to be injected into the tree by a professional but is effective if properly done. Until you know whether you are dealing with oak wilt for sure, you cannot really do anything.
Read more about oak wilt here: https://www.canr.msu.edu/resources/smart-gardening-to-prevent-oak-wilt
I would recommend acting on this quickly.
Thank you for contacting Ask Extension.
Ruth
