Oak wilt - Ask Extension
Hello! We just planted this oak tree in spring of 2023. It did well last year, but this year, a majority of the leaves have turned brown. Two other tr...
Knowledgebase
Oak wilt #875375
Asked June 30, 2024, 4:56 PM EDT
Hello! We just planted this oak tree in spring of 2023. It did well last year, but this year, a majority of the leaves have turned brown. Two other trees -- different species -- have done well about 10 yards apiece, so we think they have had sufficient moisture. Note in the attached pictures that the leaves have some unusual brown patterns. Is this oak wilt? Not enough moisture? Something else?
Sac County Iowa
Expert Response
There are a number of diseases and environmental factors that can cause browning of the foliage of an oak tree. For trees in the red oak group, the symptoms of oak wilt start at the uppermost part of the tree and work down. Leaves turn a dull, bronzed brown at the tips and along the outer margins, with a sharp line separating discolored from normal green tissue. The discoloration progresses toward the leaf base and the midrib. From what I can see in the photos, this is not quite what is happening. The issue could be from a different oak disease - many of them have very similar symptoms. You can use this guide to evaluate your tree to determine if any of the symptoms align with what you can see in person. https://yardandgarden.extension.iastate.edu/files/inline-files/howtorecognizecommondiseasesoaks.pdf
I suspect this is not damage from a disease or insect. The leaves appear to be browning in between the veins and the damage seems to be spread throughout the tree canopy. This could be injury due to lack of water from dry soils or a compromised root system that prevents the tree from taking up moisture, despite the ground being moist.
There are many reasons why newly planted trees can show stress. This article reviews those reasons. Evaluate your environmental conditions and potentially identify the issue (or issues) that could be causing problems. Management steps for these types of environmental issues are to correct the situation and provide good consistent care in an effort to help the tree recover/grow out of the issue.
https://yardandgarden.extension.iastate.edu/how-to/decline-newly-planted-trees
While I don't suspect this is oak wilt based on what I can see in the photos, testing is the only way to know for certain. More information on testing and how to submit a sample are here, if you are interested: https://yardandgarden.extension.iastate.edu/files/article/files/pidc46_2018_oak_wilt_sampling_checklist.pdf
I suspect this is not damage from a disease or insect. The leaves appear to be browning in between the veins and the damage seems to be spread throughout the tree canopy. This could be injury due to lack of water from dry soils or a compromised root system that prevents the tree from taking up moisture, despite the ground being moist.
There are many reasons why newly planted trees can show stress. This article reviews those reasons. Evaluate your environmental conditions and potentially identify the issue (or issues) that could be causing problems. Management steps for these types of environmental issues are to correct the situation and provide good consistent care in an effort to help the tree recover/grow out of the issue.
https://yardandgarden.extension.iastate.edu/how-to/decline-newly-planted-trees
While I don't suspect this is oak wilt based on what I can see in the photos, testing is the only way to know for certain. More information on testing and how to submit a sample are here, if you are interested: https://yardandgarden.extension.iastate.edu/files/article/files/pidc46_2018_oak_wilt_sampling_checklist.pdf
Thanks for the detailed response! Lance W.
