White Oak Leaf problem - Ask Extension
My white oak is about 150-170 years old. It is located about 30 feet from our lake. Other white oaks on the lake do not have this condition. I've been...
Knowledgebase
White Oak Leaf problem #842665
Asked July 26, 2023, 9:11 AM EDT
My white oak is about 150-170 years old. It is located about 30 feet from our lake. Other white oaks on the lake do not have this condition. I've been aware of the condition since we moved here 17 years ago. Different "arborists" have identified the issue as "wilt, anthracnose, blister, iron or nitrogen deficiency, etc." The tree is too big to spray. Is there a systemic (root) solution for this condition that I could inject into the soil?
Oakland County Michigan
Expert Response
Hello,
The oak does have some anthracnose symptoms, (the brown spotting on the leaves) but this is a common fungal disease that does not impact the health of the tree. What I would be more concerned about is that the leaves appear chlorotic which can be a sign of several things. I would suggest getting a soil test to rule out nutrient deficiency. That would be the simplest thing to rule out and remedy. Here is how you would go about getting that done:
https://homesoiltest.msu.edu/get-started
If that is not the problem, it may be bacterial leaf scorch, for which there is no remedy. (https://extension.umd.edu/resource/bacterial-leaf-scorch-trees)
If that is the case, the tree will need some extra TLC in the way of watering during drought, and possible pruning in the winter to remove dead wood. (https://www.canr.msu.edu/news/smart-gardening-to-prevent-oak-wilt) I am not suspecting oak wilt because of the duration of the symptoms. Oak wilt will kill white oaks more slowly than red oaks, but I think 17 years is probably more than even a white oak could survive oak wilt. Here is an article about how to water a mature tree: https://extension.umn.edu/planting-and-growing-guides/watering-established-trees-and-shrubs
I hope this is helpful.
Thank you for contacting Ask Extension.
Ruth
The oak does have some anthracnose symptoms, (the brown spotting on the leaves) but this is a common fungal disease that does not impact the health of the tree. What I would be more concerned about is that the leaves appear chlorotic which can be a sign of several things. I would suggest getting a soil test to rule out nutrient deficiency. That would be the simplest thing to rule out and remedy. Here is how you would go about getting that done:
https://homesoiltest.msu.edu/get-started
If that is not the problem, it may be bacterial leaf scorch, for which there is no remedy. (https://extension.umd.edu/resource/bacterial-leaf-scorch-trees)
If that is the case, the tree will need some extra TLC in the way of watering during drought, and possible pruning in the winter to remove dead wood. (https://www.canr.msu.edu/news/smart-gardening-to-prevent-oak-wilt) I am not suspecting oak wilt because of the duration of the symptoms. Oak wilt will kill white oaks more slowly than red oaks, but I think 17 years is probably more than even a white oak could survive oak wilt. Here is an article about how to water a mature tree: https://extension.umn.edu/planting-and-growing-guides/watering-established-trees-and-shrubs
I hope this is helpful.
Thank you for contacting Ask Extension.
Ruth
Thanks for the comprehensive and prompt reply, Ruth. I will follow-up on each suggestion.
Ron
