More trees with Emerald Ash Borer in Newtonville; EAB is likely present in all of Newton

NNHS ash trees on Elm Road

Add at least two, and presumably three more ash trees found to be infested with Emerald Ash Borer in Newtonville alone this summer. The most recent are a grove of three ash near the Elm Road entrance of Newton North High School. Two of the trees have at least one exit hole visible from the ground, and all three have thinning in the upper canopy.

Since this Fall 2016 article in the Newton Conservators newsletter about the first signs of EAB in Newton, there were occasional further discoveries: four large dead or dying ash trees on conservation land across from Mason-Rice, and a couple by the Newton Country Day School athletic field entrance on Centre Street.

From ground level, only found one exit hole on this NNHS ash. Infestations affect the upper canopy first.

But this summer is seeing a flurry of trees showing visible effects of infestation: thinning in the upper canopy, accompanied by an exit hole or two visible from ground level. (There would likely be many more exit holes in the upper canopy.)

A heavily infested ash on California Street at Nevada Street is the first we know about in Newton north of the Mass Pike.

California Street at Nevada

While it appears that the northeast section of Newton was the first area to become infested, other areas of Newton can be presumed to already have EAB present. Based on its flying range, protective treatment is recommended for ash trees within 15 miles of a known infestation. That radius includes all of Newton.

If you’re not sure whether you have an ash tree, watch the video above. (The only other opposite branching species that may be confused with ash is the box elder, a type of maple with compound leaves, but with notches, that when overlapped resemble a maple leaf.)

If you have an ash tree that you value and want to keep around, please check out, and consult an arborist from a good tree care company about treatment options. The most used treatment protocol involves trunk injections every other year. Not all ash trees will be worth saving, but for a large, healthy tree, the cost of treatment, even over many years, will likely be less than the cost of removal, and you will have the enjoyment of the tree.

Long term, there is some hope for a biological control, according to UMass Extension’s fact sheet. Four different parasitoid wasps have been approved for release in the U.S., and a very small percentage of ash in North America show signs of resistance to EAB. So perhaps there is a chance that genus Fraxinus will not become as rare as the American chestnut.

Epicormic shoots on California Street ash. They are common on stressed trees, but not exclusive to EAB-infested trees.

Exit holes on trunk of California Street ash


Relatively early stage infestation on Walnut Street, Newtonville. (1-2 exits holes visible from ground). If your tree looks like this, it’s probably worth trying to save it.