Hello Tim,

We've reviewed your photos and the symptoms you have described. Some of the symptoms we see indicate an abiotic issue, i.e., irrigation, pesticide application, etc., while others indicate a biotic issue, i.e., a fungus. However, it is difficult to ascertain the issue without additional photos and answers to some questions.

Photos needed, please: 

-entire tree 

-photos of other affected trees (entire tree)

-photo of base of tree

-photo of canopies

Answers needed, please:

-Has herbicide / pesticide other than EAB treatment been applied ANYWHERE recently?

-Are other affected ash trees close by?

-Age of trees approximately?

-Location (N S E W)

-Area when trees grow, i.e., is it prone to bogginess or not?

-When did the problem start?

-Do you see the presence of insects on the affected areas?

Please send us your zip code when you reply, too.

Thank you.

Sincerely,

Anne C. & Becky C.

Oh , I think the problem is probably a pesticide drench I put on all of my 4 ash trees. For the last two years I used a product called " Compare & Save " tree & shrub insect drench.  It's active ingredient is imadacloprid. I had been concerned about my largest ash tree losing its leaves at the very top (earlier than 2 years ago). An arborist told me that the loss of leaves at the  top of the canopy  wasn't EAB, but some other pest.

About a half year after using the drench,  one tree started having  leaves fall off  some of its lower branches last Summer. This year all the ash trees are affected . Then, I also had the trees treated  blast Fall by a company to prevent EAB . I thought I was doing a good thing for them, not realizing I was mostly likely causing the problem.

These trees are all in my backyard, which faces East in zip code 80120.

Do you think these trees are likely to survive?  Are the branches that have lost leaves dead, or can they recover?

Hi Tim,

Thank you for your response. The good news is that less than 30% of the tree has been affected, so the tree should survive. We would expect that the leaves of the ash tree would be out by this time, so the branches without leaves should be pruned out. When doing so, look for any signs of insect presence or holes in the branches. The pruning can be done at any time. 

The branches that died could have been due to cankers. Cytospora cankers can affect ash trees, so this would be good to rule out. Cankers are dead areas on bark or stems often sunken or discolored. Here is an article on cytospora cankers:Cytospora Canker (colostate.edu). 

The branches could also have been killed by weather related issues. Winter watering is very important for tree health. Here is a fact sheet on fall and winter watering: Fall and Winter Watering (colostate.edu)

We appreciate your concerns with EAB. From your email, we couldn't tell when your pesticide treatments were applied. Here is more information regarding the use of pesticides for the control of emerald ash borer: Insecticides Used to Control Emerald Ash Borer on Residential Shade Trees - 5.626 (colostate.edu)

Thank you so much for your question!

Kristen and Elaine