Header Graphic
Emerald Ash Borer

The Emerald Ash Borer has been widely publicized as a serious threat to Michigan ash trees. If you have ash trees in your landscape that are still viable, you will have some decisions to make regarding those trees.

The pest is not selective when it comes to ash trees.  It will attack them and ultimately kill them, unless they are protected.  Fortunately, there are very effective preventive treatments available.  The very best, as proven by research at several universities, is TREE-Age, emamectin benzoate. 

2022 will be our 20th year using the Arborjet system for treating ash trees.  Among the ash trees we have treated with this system, none of the healthy ones have become infested and the trees which were already infested have at least stayed the same with no worsening or have improved.  We have done over 23,000 ash treatments and have observed excellent control of Emerald Ash Borers


We have been using TREE-Age, (emamectin benzoate) since May of 2008, when it first became available.  Emamectin has been tested by Michigan State University researchers and found to protect ash trees with 99 to 100% kill rate on Emerald Ash borer adults and larvae.  A recent publication fact sheet confirms the superiority of this chemical over all others.  See results of various treatments at this link:  http://www.emeraldashborer.info/documents/Multistate_EAB_Insecticide_Fact_Sheet.pdf

Read pages 12, 13 and 14 about the efficacy of various products.  


WHAT ABOUT POINTER (IMIDACLOPRID) OR ACECAPS (ACEPHATE) ?  These chemicals have not been shown to be nearly as effective or long-lasting ash emamectin.  Imidacloprid treatments would have to be done every year, as would acephate injections.  If that involves punching holes through the bark or drilling holes into sapwood, it would be unnecessarily invasive and damaging if done every year.  And in the study noted above, even annual treatments did not show consistent control, with trees exhibiting continuing decline even with annual treatments with these other chemicals.  


There are several methods of administering chemicals to trees, but we believe the Arborjet system is the very best, based on the research and on our own experience.  Small holes are drilled, retainer plugs are placed and the chemical is injected into the active sapwood of the tree, using a quikjet injector or Quikjet Air injector.  These treatments give two years of control with one treatment and give both better control and longer lasting control than any other method. CURRENT LABELING of this product is that it provides UP TO 2 years of control after each injection.  However, some have used a three year interval between injections.  We still feel that for ideal control, a two year interval is best, although the insecticide fact sheet above suggests that three year interval would be adequate. 


Drilling to apply this chemical is NOT a problem for the tree!

Some companies will advise that trees should not be drilled to administer chemicals and will advise other methods of application.  There are several problems with this argument:  1) Drilling is the only way to administer the very best treatment that can save infested ash trees and protect them for a full two to three years  2)  Trees infested with ash borers need life-saving treatment administered in any way possible  3)  a recently published report documents that the trees do not suffer harm after these treatments- the trees show excellent healing response, growing good healthy wood over and around the injections sites with no decay or other problems.  See this link:  http://www.cityofelgin.org/DocumentView.aspx?DID=12393


 Current Recommendations

1.   Valuable ash trees should be treated before infestation if possible.  Trees larger than 8 inch trunk diameter should be treated by trunk injection.

2.   If ash trees are showing thinning, defoliation and/or branch dieback, they may be salvaged if damage is not severe.  Injection plus fertilization may be needed.

3.   Injection with emamectin (TREE-Age) using the Arborjet system should be done every two (maybe three)  years to prevent initial infestation or further infestation or damage.  If scale infestation is present, we can use an additional chemical with the emamectin. 

4.   Trees smaller than 8 inch trunk diameter may be treated by basal soil drench or ground injection using imidacloprid.  Homeowners can treat the small trees with imidacloprid available from garden centers. See page on homeowner ash treatment.

5.   The cost (see below) varies based on the chemical used and tree size because larger trees need higher dosage per trunk diameter inch.  Usual cost is 7 to 16  dollars per trunk diameter inch.  It is usually far less expensive to treat the tree to keep it alive than to pay to have it removed when it dies.

6.   CAUTION!  Not all treatments are created equal.  The only homeowner treatment that should be used is imidacloprid ground drench on trees under 8 inch diameter.  Sprays are much less effective for either ash borers or scale.  Trunk injection by micro-infusion, specifically with the Arborjet system is proven to be superior to other methods.  

Lawn care companies and companies without certified arborists on staff may not be using the optimal methods.  We recommend that you find a company with Certified Arborists guiding the treatments or doing the treatmentsWe always have a certified arborist guiding the treatments.


EMAMECTIN  (TREE-Age)  charge for treatment is 7 to 16 dollars per trunk diameter inch.  The 7 dollar rate is for trees less than 10 inches diameter*.  The rate per inch is higher for bigger trees, up to 12 dollars per diameter inch in the largest trees.  The treatment should be done every two years (label rate).  Ongoing studies are suggesting that three year control may be possible with this chemical if administered at higher dosage.  Further studies are needed before we can recommend it for three year control.

* (One caveat- if you have only one tree, the minimum charge is $100 for us to send a vehicle and two or three men to do just one tree)

BOTTOM LINE COST  amounts to about 4 to 8 dollars per trunk diameter inch per year to provide optimal control of ash borers and other ash pests.  So a 10 inch ash tree costs about 35 dollars per year to keep alive and healthy*.  Compare that to the cost of having the tree removed-  350 (front yard)  to 700 dollars (fenced in back yard), depending on location.  So you can keep the tree healthy for 7 to 14 years for the same cost as having it removed.

FREE ESTIMATE OF COST OF TREATMENT.  We can come and measure your trees to give you an estimate of the cost of treatment and advise you as to which chemical should be used.  Or, you can measure your trees yourself by measuring around the tree (circumference) at chest height.  Then multiply that number by 2 (for trees 36 inches around or less)* or  3 (37 to 60 inches around) or 4 (trees more than 60 inches around  to determine the approximate cost of treating that tree for two full years.  If we treat multiple trees at one address or in one neighborhood, discounts are possible.  Also, we offer payment plans for large contracts.

* see above regarding just one tree at a residence.

GUARANTEED EFFICACY.  We are so confident in TREE-Age that we offer a money back guarantee.  If any tree that is in reasonably good shape (at least 75 percent canopy leafed out) when treated dies of Emerald Ash Borer infestation, we will refund the cost of treatment.  This warranty is good for the recommended duration of action and circumstances noted above.  If requested, we will provide this warranty in writing.  SEE PAGE ON GUARANTEES AND WARRANTIES FOR MORE DETAILS.


 TriCity Tree Doctor  Call us at 989-454-0227

United Tree Service  Call us at 810-266-4363