Emerald Ash Borer (EAB) reached Waterloo Region in the mid-2010s and has worked through most of the unprotected ash population. What's left, in 2026, is a mix of dead and dying trees, trees on treatment programs, and untreated survivors that are usually one or two seasons from decline.
How to tell if your ash is infested
Ash trees show EAB symptoms in this rough order:
- D-shaped exit holes in the bark — usually 3-4 mm wide. Diagnostic.
- Crown dieback starting at the top — bare branches in the upper canopy while the bottom still leafs out.
- Epicormic shoots — small new shoots emerging from the trunk and main scaffold branches as the tree tries to compensate.
- Vertical bark splits exposing serpentine larval galleries underneath.
- Woodpecker damage — patches of flaked-off outer bark where birds have been hunting larvae.
Is treatment still worth it?
Yes, if the tree is caught early enough. TreeAzin injection (the most common treatment in Ontario) is most effective when:
- Crown dieback is less than 30%.
- The tree is otherwise structurally sound.
- You're willing to commit to a 2-year treatment cycle indefinitely.
Above 30% dieback, removal is usually the better investment — the canopy will not recover, and dead ash becomes brittle and dangerous to remove within 2-3 years.
Dead ash is the most hazardous wood to remove in our industry. Get to it while the rigging is still safe.
If you're removing — sooner is cheaper
The longer an ash has been dead, the more brittle it becomes. After about three years of decline, the wood fractures unpredictably when climbed or rigged. That changes the job from a standard removal to a crane removal — often double the cost. If a tree is past treatment, get it down within 12-18 months.
What we offer
- Free EAB assessment — we'll tell you honestly if treatment is worth it.
- TreeAzin injection programs on a 2-year cycle.
- Safe removal of dead or declining ash, including crane-assisted takedowns for the worst ones.
Request an assessment or call (226) 263-2319.