Emerald Ash Borer (EAB) is one of the most destructive invasive forest pests ever introduced to North America. This small metallic-green beetle attacks and kills ash trees by feeding beneath the bark, disrupting the tree's ability to transport water and nutrients.
Emerald Ash Borer is now established throughout much of Maine and continues to spread across Southern Maine communities. Without treatment, most infested ash trees will decline and eventually die.
At Tree Medics, we specialize in diagnosing and treating Emerald Ash Borer infestations, helping homeowners, businesses, and municipalities preserve valuable ash trees before irreversible damage occurs.
Adult beetles emerge in late spring and lay eggs within the bark crevices of ash trees. After hatching, the larvae tunnel beneath the bark and feed on the tree's vascular system.
As these feeding galleries expand, they effectively cut off the flow of water and nutrients throughout the tree. Over time, the canopy begins to decline, branches die back, and the tree eventually succumbs to the infestation.
Thinning canopy and leaf loss
Dead branches in the upper crown
Epicormic sprouts growing from the trunk or lower branches
Increased woodpecker activity
Vertical bark splitting
Distinctive D-shaped exit holes
S-shaped galleries beneath the bark
The most effective treatment for Emerald Ash Borer is a systemic trunk injection. This treatment is delivered directly into the tree's vascular system, where it protects the tree from feeding larvae.
For most ash trees, treatment is typically repeated every two years to maintain protection and preserve long-term health.
Trunk injections are highly targeted, environmentally responsible, and have successfully protected millions of ash trees across North America.
Once symptoms become visible, Emerald Ash Borer can kill:
Smaller ash trees in as little as 1–3 years
Larger mature ash trees in approximately 2–5 years
The sooner an infestation is detected, the greater the likelihood of successful treatment and recovery.
In many cases, yes.
Ash trees showing early to moderate signs of infestation are often excellent candidates for treatment. Trees with less canopy loss and good overall structure frequently respond very well to trunk injections.
However, severely declining trees with extensive canopy loss, significant bark damage, or advanced structural deterioration may no longer be good candidates for preservation.
A professional assessment is the best way to determine whether treatment or removal is the most appropriate option.
Not necessarily.
Many healthy and moderately infested ash trees can be successfully preserved for decades with ongoing treatment. In fact, preserving a mature ash tree is often significantly less expensive than removing and replacing it.
Our specialists evaluate each tree individually and provide honest recommendations based on its health, structural condition, and likelihood of recovery.
Mature ash trees provide tremendous value to your property and community, including:
Shade and energy savings
Increased property value
Wildlife habitat
Stormwater management
Environmental benefits
Neighborhood character and beauty
Protecting healthy ash trees today can preserve these benefits for generations to come.
If you have an ash tree on your property and are concerned about Emerald Ash Borer, don't wait until symptoms become severe.
Tree Medics provides professional Emerald Ash Borer inspections and treatment programs throughout Southern Maine. Our goal is simple: diagnose problems early, preserve healthy trees, and help property owners make informed decisions about their landscape.
Tree Medics — Healing Trees. Restoring Nature.