How can I help my sick ash trees?

Asked August 8, 2015, 5:11 PM EDT

I have two very sick ash trees. The trees are 30 years old and are 50 inches around chest height and have signs of bore holes and curling up of leaves. When I have cut off old dead branches, they show signs of boring in the center of the limb. Can you help me help my trees please? I can send pics or samples.

Larimer County Colorado

1 Response

Hi Chris,

Yes, photos of your tree would be very helpful. Please send me photos of the tree as a whole and also of the boring injury you're seeing. Emerald ash borer has been confirmed in Boulder County (not Larimer) but we're taking all precautions. Another insect it could be is the lilac-ash borer, which is extremely common.

Here is information on lilac-ash borer:

The boring injury from LAB is round holes on the trunk, about the size of a pencil eraser. Emerald ash borer makes "D-shaped" exit holes, about 1/8" in diameter.

The leaf curl could be due to aphid leaf curl, which my co-worker, Eric, recently blogged about:

In short, there are many possibilities as to what is affecting your ash tree. You can email me photos directly at:

Please note that my email can only accept up to 15mb per email. If you send multiple photos, please send multiple emails.