Sick oak tree - Ask Extension
Wondering if you might be able to help me figure out why my oak tree looks so bare. I’m sending a couple of pictures. The leaves look like they are ...
Knowledgebase
Sick oak tree #797975
Asked June 26, 2022, 8:05 PM EDT
Wondering if you might be able to help me figure out why my oak tree looks so bare. I’m sending a couple of pictures. The leaves look like they are curling and the tree looks so bare of foilage. Thank you
Saginaw County Michigan
Expert Response
Good Morning,
It's possible your tree has oak wilt.
The first symptom is browning leaves at the top of the tree. Leaves brown from their margins at the end of the leaf and continues to progress along the margins and down towards the mid-vein and stem of the leaf. Whole branches may be seen yellowing and then browning as the disease progresses down the branch. This is first seen in late spring to early summer. Leaves litter the ground around the tree as the tree wilts. Another symptom is a fungal mat that grows under the bark, creating pressure causing bark to crack. These fungal mats attract sap beetles where the insects pick up spores of the disease, carrying it to uninfected trees that are freshly wounded, releasing the spores as they feed.
A correct diagnosis is critical to reducing the spread of the disease. Since other disease and problems can be confused with oak wilt, Michigan State University Extension recommends having trees inspected by a certified arborist, Find an Arborist (treesaregood.org) and it would be beneficial to send samples to a diagnostic laboratory where the fungus can be identified. MSU Diagnostic Services advises to submit samples to their lab from partially wilted branches 1 inch in diameter. Cut branches into 6- to 8-inch lengths, place in bags to be delivered or overnight shipped to the lab. The MSU Diagnostic Services website provides directions on taking samples and how to submit samples. Fresh samples are necessary for testing for the oak wilt fungus.
References
Oak wilt: Diagnosing and preventing - MSU Extension
Oak wilt disease - MSU Extension
I hope this helps. Thanks for using our service.
It's possible your tree has oak wilt.
The first symptom is browning leaves at the top of the tree. Leaves brown from their margins at the end of the leaf and continues to progress along the margins and down towards the mid-vein and stem of the leaf. Whole branches may be seen yellowing and then browning as the disease progresses down the branch. This is first seen in late spring to early summer. Leaves litter the ground around the tree as the tree wilts. Another symptom is a fungal mat that grows under the bark, creating pressure causing bark to crack. These fungal mats attract sap beetles where the insects pick up spores of the disease, carrying it to uninfected trees that are freshly wounded, releasing the spores as they feed.
A correct diagnosis is critical to reducing the spread of the disease. Since other disease and problems can be confused with oak wilt, Michigan State University Extension recommends having trees inspected by a certified arborist, Find an Arborist (treesaregood.org) and it would be beneficial to send samples to a diagnostic laboratory where the fungus can be identified. MSU Diagnostic Services advises to submit samples to their lab from partially wilted branches 1 inch in diameter. Cut branches into 6- to 8-inch lengths, place in bags to be delivered or overnight shipped to the lab. The MSU Diagnostic Services website provides directions on taking samples and how to submit samples. Fresh samples are necessary for testing for the oak wilt fungus.
References
Oak wilt: Diagnosing and preventing - MSU Extension
Oak wilt disease - MSU Extension
I hope this helps. Thanks for using our service.
