The emerald ash borer has moved through this peninsula, and I have taken down a lot of ash trees because of it. The signs are always the same: the crown thins from the top down, shoots break out along the trunk, bark splits, and underneath you find S-shaped galleries and small D-shaped exit holes. I can tell you honestly which trees can be saved with injection and which ones need to come down before they become dangerous.
What emerald ash borer actually involves in St. Catharines
The emerald ash borer is a small metallic green beetle, about the size of a grain of rice, that came to North America from Asia. It lays eggs on ash trees, and when the larvae hatch, they tunnel under the bark in S-shaped galleries. These tunnels cut off the flow of water and nutrients through the tree, eventually killing it from the inside out.
You will not see the beetle itself very often. What you see instead are the damage signs: the D-shaped exit holes where adult beetles emerge in late spring and early summer, the serpentine galleries if you peel back loose bark, and the overall decline of the tree. The borer attacks all species of ash, and once it gets into a tree, there is no stopping it without intervention.
This pest arrived in Ontario years ago and has been spreading steadily. It is now present throughout the St. Catharines area, and any ash tree showing decline should be inspected. The longer you wait, the fewer options you have.
Why it matters
If I do not catch an infested ash tree early enough, it will die. A dead ash becomes brittle and extremely dangerous to climb. The wood loses all flexibility and can snap without warning, and that is how climbers get hurt. Beyond safety, a dead ash is also more expensive to remove because the wood is unpredictable and the branches can fail during takedown.
Catching the borer early means I can inject the tree with a systemic insecticide that kills the larvae before they girdle the trunk. This keeps the tree alive and saves you the cost of removal. If the tree is already too far gone, removing it while it still has some canopy is much safer and cheaper than waiting until the crown is completely dead.
Leaving an infested ash standing also spreads the problem. The beetles will emerge and fly to neighbouring trees, including your own other ash trees and those of your neighbours. Taking action protects your property and the whole neighbourhood.
When to schedule emerald ash borer in the St. Catharines area
The best time to spot emerald ash borer damage is late spring through early autumn, when the exit holes are fresh and the crown thinning is obvious. However, I can diagnose the problem any time of year if I know what to look for.
Watch for these signs on any ash tree on your property: the crown thins from the top down, not from storm damage or disease, but as a steady decline; small D-shaped holes appear in the bark, about the size of a grain of rice; shoots or sprouts break out along the trunk and lower branches as the tree tries to recover; and bark peels away in strips, revealing the tunnels underneath.
If you see any of these, do not wait for spring. Call me in autumn or winter and I can assess whether the tree can be treated or needs to be removed. Early diagnosis means I can inject it before the next generation of beetles emerges. If you wait until late spring, the larvae are already feeding and injection is less effective.
How it works
When you call, I come out and climb the tree or use binoculars to inspect the crown and trunk. I look for exit holes, bark damage, crown thinning, and the overall health of the canopy. I will tell you honestly what I find and what your options are.
If the tree still has most of its canopy and the damage is caught early, I can inject it with a systemic insecticide. The injection is done at the base of the tree using a special applicator, and the product moves up through the tree's vascular system to kill the larvae. You will need to do this on a treatment cycle, usually every year or every other year depending on the product and the severity of infestation.
If the top is already dead or the crown is too thin, removal is the only option. I will cut the tree down in sections, chip the branches, and either haul away or split the trunk for firewood, depending on what you want. I clean up all debris from the site and leave it ready to use.
After removal, you may want to plant a replacement tree that is not an ash. I can advise on species that do well in this area and are resistant to other pests.
The different cases and what to do
The tree can be saved. The crown still has most of its foliage, the thinning has just started, and I can see only a few exit holes or bark damage. This tree is a candidate for injection. I will give you a free Estimate for the treatment and explain the ongoing cycle. You will need to commit to regular injections, but the tree will stay standing and healthy.
The tree is declining but not dead. The crown is noticeably thin, there are many exit holes, and bark is peeling in several places. The tree is heavily infested but still has a canopy. Removal is safer and cheaper now than waiting. If you remove it now, the job is straightforward and the wood is still manageable. If you wait another year or two, the tree becomes brittle and dangerous, and the cost rises.
The tree is dead or nearly dead. The top is bare or nearly bare, the trunk is brittle, and the whole tree is unstable. This tree must come down as soon as possible. Climbing a dead ash is genuinely dangerous, and every delay makes it worse. I will remove it, but the risk and the cost are both high. Do not let your ash tree get to this point.
Multiple ash trees on the property. If you have more than one ash tree, I will inspect all of them. Some may be candidates for injection, others for removal. I will prioritize based on location, health and safety risk, and your budget.
