Emerald Ash Borer has reshaped the tree canopy across Ontario, and Waterloo Region has lost a huge number of ash trees to it. The good news is that EAB leaves a recognisable trail — if you know what you're looking at, you can often catch an infestation while there's still a decision to make.
The signs to look for
EAB larvae feed under the bark, cutting off the ash tree's ability to move water and nutrients. The classic symptoms, roughly in the order they appear:
- Canopy thinning — the upper crown starts to look sparse and washed-out.
- Woodpecker activity — heavy "flecking," where birds strip outer bark to reach larvae, is often the first thing homeowners notice.
- Bark splitting — vertical cracks over the larval galleries.
- D-shaped exit holes — tiny, distinctive holes (about 3–4 mm) left by emerging adult beetles.
- Epicormic shoots — desperate new growth sprouting from the trunk and base.
Is it only ash?
EAB attacks ash trees (genus Fraxinus) — white, green and black ash. If you're not sure whether you even have an ash, that's the first thing to confirm; the treatment-or-removal question only matters if it's a host tree.
Woodpeckers hammering an ash tree are rarely after the tree. They're after what's already living under the bark.
Treat or remove?
A healthy ash caught early can sometimes be protected with TreeAzin injections on a multi-year schedule. An ash that's already lost much of its canopy is usually past saving and becomes brittle and dangerous fast — dead ash are notorious for failing without warning. If you have an ash showing these signs, book an assessment and we'll give you a straight treat-or-remove answer.