The emerald ash borer has been moving through the ash trees in this region for years now, and it does not forgive waiting. An infested ash left untreated dies on a predictable timeline. I assess the crown thinning, the D-shaped exit holes, and the woodpecker damage to give you an honest read on whether injection still makes sense or whether the tree has passed that point. If it is treatable, I coordinate the injection cycle. If it is not, I remove it before the wood becomes brittle.
What emerald ash borer actually is
The emerald ash borer is a small metallic green beetle, roughly the size of a grain of rice, that arrived in North America from Asia. Once it finds an ash tree, the adult lays eggs in cracks and crevices in the bark. Those eggs hatch into larvae that tunnel under the bark and feed on the phloem and sapwood, the living tissue that carries water and nutrients up and down the tree. This feeding disrupts the tree's ability to transport water, and the tree begins to starve from the inside.
What makes this pest so destructive is that by the time you see obvious symptoms, the larvae have often been feeding for a year or more. An ash tree can look relatively healthy on the outside while harbouring hundreds of larvae underneath. The borer does not discriminate between species of ash, and it has no natural predators here to keep its population in check. Once established in a tree, it spreads to neighbouring ash trees through flight or hitching rides on firewood and logs.
Why it matters in Port Credit
If you leave an infested ash untreated, you are watching a countdown to a dead tree. A dead ash becomes one of the worst trees there is to climb because the wood loses its flexibility and becomes brittle. Branches snap without warning, and the trunk itself can fracture unpredictably. That brittleness also means the tree is more likely to shed large limbs during a windstorm, creating a hazard over your house, your neighbours' property, or the street.
Beyond safety, a dead ash sitting in your yard for months becomes a visual problem and a liability. Removing it while it still has some structural integrity is safer for me, faster to execute, and less disruptive to your property. Treatment, when caught early enough, can preserve a tree you value and avoid the cost and mess of removal altogether. The key is acting as soon as you spot the signs, not waiting until the tree is clearly dying.
When to do emerald ash borer?
Emerald ash borer activity in this region peaks in late spring and early summer when the adults emerge and begin laying eggs. However, the signs of infestation can appear at any time during the growing season. The earliest visual clue is crown thinning, where the upper branches begin to lose foliage and look sparse or transparent compared to the rest of the canopy. You may also notice small D-shaped exit holes in the bark, roughly the size of a pinhead, where adults have chewed their way out.
Woodpecker damage is another red flag. Woodpeckers are attracted to ash trees infested with emerald ash borer larvae because they are easy prey. If you see patches of bark stripped away or shallow pits in the trunk where a bird has been feeding, that tree likely has a significant borer population. Late summer and early autumn are good times to call because I can assess the tree's condition and plan a treatment or removal before winter makes the work harder. Do not wait until spring if you suspect an infestation, because the larvae will have had months to spread deeper into the wood.
How I work in Mississauga neighbourhoods
When you call me, I come out to your property and spend time looking at the tree. I examine the crown, the bark, and the overall structure. I ask you how long you have owned the tree and whether you have noticed any changes in its growth or appearance. I take photographs and notes so I can give you a clear, honest assessment. If the tree is in early stages of infestation and still has good structural integrity, I can recommend injection treatment. If the infestation is advanced or the tree is already in decline, I explain why removal is the safer and more practical option.
If treatment is the route, I coordinate the injection schedule with a certified applicator. Injections are typically done in late spring, and the tree needs monitoring over the following months to assess whether it is responding. If removal is necessary, I schedule the work, bring my equipment, and take the tree down in sections, lowering each piece safely to the ground. I then chip the debris or stack it for removal, and I clean up the site thoroughly. You receive a free estimate before any work begins, and I keep you informed every step of the way.
The situations I run into
Early infestation with good tree structure. The tree shows crown thinning and a few exit holes, but the main scaffold branches are sound and the overall form is still intact. Treatment with injection can be effective. I coordinate the application and follow up to monitor the tree's response over the next growing season.
Advanced infestation with significant crown loss. The tree has lost more than half its foliage, exit holes are numerous, and woodpecker damage is visible. The tree is unlikely to recover from injection, and continuing to treat it would be a waste of your money. Removal is the honest recommendation.
Dead or dying ash with brittle wood. The tree has no leaves, the bark is peeling, and the wood is becoming soft or crumbly. This tree is a climbing hazard and a liability. I remove it before it sheds limbs or fails in a storm. The sooner this happens, the safer the job.
Ash tree with no visible signs but located near known infested trees. If you have multiple ash trees on your property and one is clearly infested, the others may be harbouring early-stage larvae. I can recommend preventive monitoring or treatment as a precaution, depending on the tree's age and value to you.
