DIY Treatment for Emerald Ash Borers

DIY Treatment for Emerald Ash BorerAs frugalistas, we’ve been spending some time over the last year or so seeking a DIY treatment for Emerald Ash Borers (EAB).

We’ve been hearing over the past several years that the Ash Borer epidemic was on it’s way to Western New York.  It’s spreading throughout the northern hemisphere at an incredible rate, and, according to the EAB Network has killed hundreds of millions of ash trees in North America alone.

Who is this metallic green monster?

Smaller than a penny, the adult ash borer nibbles on leaves …which would be considered benign, but their devilish larva is the problem.  It feeds on the inner bark of the tree until it reaches adulthood, leaving a trail inside the tree that causes permanent damage and ultimately death to the tree.

Home treatment option for Emerald Ash Borer



Identify your Ash Trees

Do you have Ash trees? We thought we might have lots of them because of the opposing branches on our trees, like the ones in this picture from my “birdhouse tree”.

The red dots point out opposing branches on the ash tree

The red dots point out opposing branches on the ash tree

Maple and dogwood trees also have a similar branch pattern, according to this information by Dr. David L. Roberts, which offers helpful identifiers. We still weren’t sure, so we invited an arborist to our yard last year to confirm what type of trees we had, and get an idea of how much it would cost to treat them.

I’ll cut to the chase: Yes, many of our indigenous trees are at-risk ash; and we were quoted a cost of 10 dollars per inch in circumference for professional treatment. With a yard full of a dozen or more trees, many of which are 20 to 60 inches around…that equals a more intense do-it-yourself investigation.

We may or may not already be infested…a quick list of symptoms is

  • D-shaped holes in the outer bark
  • Excessive attention from woodpeckers
  • Dead branches in the upper canopy
  • Loss of leaves in the topmost branches
  • A sudden sprout of new leafing toward the lower area of the tree.

I can make a case for in-progress infestation on a couple of our trees, but there’s complete certainty for risk to all of them. One a tree is infested, it’s difficult to save: so prevention is the key.

The professional noted that their treatment uses more powerful pesticides than we can access, and their application method involves targeted drilling into the base area of the tree with professional strength pesticides.

It may be more effective, but as he noted, it’s not guaranteed…AND it has to be repeated each year. So, for us, we’d be looking at investing over $3500 per year just to save our favorites…again with no guarantee.

SO, we’re going the DIY route, which involves soil drenching at the trunk base. Still no guarantees, and frankly it feels like it might be a losing battle, but maybe it will at least buy us some time.

Several sources (listed and linked at the end of this post) suggest using Bayer Advanced Tree and Shrub Insect Control. It contains imidacloprid, which is said to be a key ingredient for combating these invaders.  As homeowners’ interest in DIYing this problem is increasing, I’ve seen other brands surface; however, we’re going with the Bayer product.


Risk to the Environment

As to the questions folks may ask regarding the effects of pesticides on bees, woodpeckers and the family pets… you can find more detailed information on potential side effects here.
The quick answers:

  • ash trees are not a nectar source, so it’s unlikely to harm bees, but you shouldn’t plant flowers in the soil near the tree because it would otherwise be harmful.
  • it’s not thought to harm woodpeckers (they don’t eat dead larvae), and will cause no harm to our family pets once it is absorbed in the soil. t
  • the report only addressed worms eating leaves, which would not be harmful; but does not say what happens to them during ground saturation (beyond that, sorry, I have no other answers).


Soil Drench Treatment

I found this very helpful video by Chris Williamson and P.J. Liesch from the University of Wisconsin Extension that gave us confidence that we could tackle this ourselves.

Following their guidelines…we purchased gallon-sized containers of Bayer Tree and Shrub concentrate (at $70 per gallon).  The concentrate is mixed it with a gallon or two gallons of water depending on the trunk size of the trees you are treating.

Measure around the tree trunk at 4.5 feet above ground (about chest height).

measure the tree trunk

We added one ounce of product for every inch of tree circumference and mixed it well. (Note: the product is shown as green in the video…ours was milky white.)

I cleared away between 18-24 inches of mulch and surface soil to create an inverted volcano shape around the base of the trunk…

clear away mulch diy ash borer

For some of the trees, I had to pull up grass…

Can I treat my own trees for emerald ash borer

I poured the mixture around the base circumference (while styling my best garden gear…you may want to consider using protective clothing)…

DIY Emerald Ash Borer Treatment

Once it was absorbed into the cleared area, I replaced the surface soil and mulch.

Now we’ll cross our fingers and hope for the best until next spring, when we will repeat this process…for years to come or until each tree succumbs.



If you come upon this article later in the year, I’ve read that you can try to make an application in autumn with some effectiveness, but spring is the optimal time (ideally, late March to the first week of May depending on when your trees are likely to break dormancy). The idea is that trees soak up more water when they’re waking up in the spring.


To any professionals reading this:

Yes! I’m sure your way is more targeted, potent and direct. Yes, I understand it will cost more to remove dead trees than to treat them. I do sincerely admire your training and education, and respect your time. Unfortunately, spending that kind of scoots annually with no guarantee is not affordable to us…so we’re left with two options: to try to save them ourselves or let them go.


Finally (for now)

I’m no professional, just a backyard gardener, but I’m not giving up our trees without at least trying to save them.

There’s a lot of information to absorb, and my hope in posting this is to encourage you not to be afraid to treat your trees if professional applications are beyond your budget.  Want more information?  Here are some great resources (including those linked above):

Emerald Ash Borer Information Network

Landscape &Tree Problems:Emerald Ash Borer – David L. Roberts, Ph.D., Senior Academic Specialist, Michigan State University, College of Agriculture and Natural Resources

MSU Evaluation of Insecticides to Control EAB Adults & Larvae David Smitley, Ph.D. and Deborah McCullough, Ph.D., Department of Entomology, Michigan State University.

Treating For Emerald Ash Borer With Bayer Advanced Tree and Shrub
Insect Control Soil Drench, Dr. Bruce Stewart, Bayer Advanced Consumer Products


ash tree