Ash tree in distress - Ask Extension
Last spring my ash tree dropped quite a few leaves. A nursery told us it was due to frost and not to worry. This year I noticed it doing the same thi...
Knowledgebase
Ash tree in distress #869325
Asked May 20, 2024, 4:42 PM EDT
Last spring my ash tree dropped quite a few leaves. A nursery told us it was due to frost and not to worry. This year I noticed it doing the same thing. When looking at the tree, I noticed several bare branches and strange or parasitic leaves growing from those branches as well as some leaves with black brown spots. Do you know what it is? And can the tree be saved? I have several more photos if needed.
Delaware County Ohio
Expert Response
Hello,
My first thought is that your tree may be affected by emerald ash borer (EAB). There are many ash trees that survived the initial onslaught of EAB several years ago, but for whatever reason, have succumbed in the years since.
Thinning in the canopy is one of the main signs of EAB infestation. I think the errant branches you’ve noticed are simply new sprouts from the dying parts of the tree rather than any indication of parasitic activity.
Carefully examine the trunk of your tree for d-shaped exit holes where the EAB beetles emerge after completing their development within the tree as larvae.
This article from Ohio State University extension has more information on what to look for to determine if your tree is affected by EAB.
There are treatments available to prevent EAB infestation, but if your tree is already declining, treatment would probably not be advisable.
The leaf spots you are noticing would not be connected to an infestation by EAB. There are several fungi that can cause leaf spots on ash trees. These normally do not cause significant damage to a healthy tree other than the premature leaf drop you noted from spring of last year. The overall decline in the canopy points to something more serious going on, which is why I suggested EAB as a potential culprit.
I would recommend that you consult a certified arborist in your area using this link for further help in diagnosing the problem with your tree and evaluating the best course of action.
You may also wish to consult your local extension office for further advice.
My first thought is that your tree may be affected by emerald ash borer (EAB). There are many ash trees that survived the initial onslaught of EAB several years ago, but for whatever reason, have succumbed in the years since.
Thinning in the canopy is one of the main signs of EAB infestation. I think the errant branches you’ve noticed are simply new sprouts from the dying parts of the tree rather than any indication of parasitic activity.
Carefully examine the trunk of your tree for d-shaped exit holes where the EAB beetles emerge after completing their development within the tree as larvae.
This article from Ohio State University extension has more information on what to look for to determine if your tree is affected by EAB.
There are treatments available to prevent EAB infestation, but if your tree is already declining, treatment would probably not be advisable.
The leaf spots you are noticing would not be connected to an infestation by EAB. There are several fungi that can cause leaf spots on ash trees. These normally do not cause significant damage to a healthy tree other than the premature leaf drop you noted from spring of last year. The overall decline in the canopy points to something more serious going on, which is why I suggested EAB as a potential culprit.
I would recommend that you consult a certified arborist in your area using this link for further help in diagnosing the problem with your tree and evaluating the best course of action.
You may also wish to consult your local extension office for further advice.
