Why are There Still Leaves on My Tree?
I recently received a question from a person asking why their ash tree still has leaves on it at this late date. The person stated that some leaves were turning brown during the summer and that they figured it was due to the drought that much of the Midwest experienced this year.
There are some trees that keep leaves that turn a fall color for a long time. Some of them remain on the tree all the way until spring. Ironwood, certain oaks and beeches are a few of the trees that keep their leaves on for a longer time than most other deciduous trees. Sometimes this is just the quality of the tree and sometimes it can be the result of some other stress factors.
In the case of the tree in question, the first clue is that it is an ash tree and the leaves started turning brown in the summer. There is a good possibility that the tree has been inhabited by Emerald Ash Borer and the dying leaves are the result of the feeding habits of the insect. Emerald Ash Borer is a destructive insect that has killed several million trees throughout Michigan, Ohio, Indiana, Illinois and many other states. The larval stage of the Emerald Ash Borer feeds on the soft tissue of the cambium layer, cutting off the supply of nutrients and water to the tree often resulting in the death of the entire tree. In this picture, you can see the result of the feeding by the larvae. You can also see how the bark easily peels away, leaving behind a complex pattern of feeding tunnels.
If you suspect your ash tree has Emerald Ash Borer, you need to have it inspected by a professional tree company or arborist. Some of the clues that the tree may be inhabited would be leaves that do not fall off in the fall, branches that are dying and the presence of "flagging", or a large congregation of branches growing out of the trunk or major branch located at the base of a dead or dying branch.
There are treatments available that will help combat this destructive insect. Success depends on the extent of the damage. In some cases, the only solution is to remove the tree.
Contact your local Spring-Green office and ask for someone to come out and inspect your ash tree to provide you with the best approach to saving it.