Knowledgebase
Oak tree dying #807168
Asked August 20, 2022, 10:39 AM EDT
Anne Arundel County Maryland
Expert Response
Hi Stephanie!
You mentioned that the gray mass in the photo appeared around the time of the cicadas; has it since disappeared?
You are correct that the next photo shows a wool sower gall, one of many galls that can appear on shade trees like yours (and none of which are harmful to your tree). It is caused by a tiny native wasp and the gall is just the swelling of plant tissue.
There is recent research by Doug Tallamy from the University of Deleware that says that native oaks are one of the most important trees to have in a healthy, biodiverse landscape, as they can support 400+ different species of insects which are an important part of the food web for birds, small mammals, reptiles, etc.
We are not sure as to the cause of your oak's decline. To assess your tree and suggest treatment (if applicable), we recommend contacting a licensed professional arborist. Anne Arundel County is accepting reports of dead/declining oak trees; you can submit your report here https://www.aacounty.org/departments/inspections-and-permits/forestry/oak-decline/oak-decline-form/index.html.
Jamie
Hi Stephanie!
You mentioned that the gray mass in the photo appeared around the time of the cicadas; has it since disappeared?
You are correct that the next photo shows a wool sower gall, one of many galls that can appear on shade trees like yours (and none of which are harmful to your tree). It is caused by a tiny native wasp and the gall is just the swelling of plant tissue.
There is recent research by Doug Tallamy from the University of Deleware that says that native oaks are one of the most important trees to have in a healthy, biodiverse landscape, as they can support 400+ different species of insects which are an important part of the food web for birds, small mammals, reptiles, etc.
We are not sure as to the cause of your oak's decline. To assess your tree and suggest treatment (if applicable), we recommend contacting a licensed professional arborist. Anne Arundel County is accepting reports of dead/declining oak trees; you can submit your report here https://www.aacounty.org/departments/inspections-and-permits/forestry/oak-decline/oak-decline-form/index.html.
Jamie
