Emerald Ash Borer Treatment in Toronto — Local business ISA Certified Arborists

The emerald ash borer continues to devastate ash trees across Toronto and the GTA, killing thousands of mature trees each year. This invasive beetle, which arrived in North America in the early 2000s, tunnels beneath the bark and cuts off water and nutrient flow, often killing a tree within two to four years of infection. Our ISA Certified Arborists assess ash trees showing early signs of attack and inject them with TreeAzin or similar systemic insecticides to stop the pest before removal becomes necessary. If your property has ash trees, early detection and emerald ash borer treatment in Toronto can save them. Call us at (437) 600-1089 for a free estimate, or visit our tree disease detection service to learn how we identify EAB damage before it spreads.

Why Emerald Ash Borer Treatment Matters in Toronto

Toronto's mature neighbourhoods contain hundreds of ash trees, many planted decades ago when the species was considered a reliable street and yard tree. The emerald ash borer has no natural predators here, and untreated infestations spread rapidly through root grafting and beetle flight. Once a tree is heavily infested, removal is the only option. Treatment works best on trees caught early, before the canopy thins significantly. Our arborists inspect the trunk, branches and bark for the telltale D-shaped exit holes, serpentine galleries and crown dieback that signal active infestation.

• Inspect ash trees for D-shaped exit holes and bark splitting, signs of active EAB feeding.
• Apply TreeAzin or similar trunk injection in late spring to early summer when beetles are active.
• Monitor treated trees annually to confirm the infestation is halted and the canopy recovers.
• Remove heavily infested trees before they become a hazard or seed the neighbourhood with new beetles.
• Document all work for your insurance company if the tree later fails or requires removal.

Early intervention saves the tree and protects your neighbours' ash stands. Delayed action often means paying more later for removal and stump grinding.

Local impact: Toronto's urban forest lost an estimated 10,000 ash trees to EAB between 2015 and 2020. Properties in Etobicoke, Long Branch and along the Don River ravine system have been hit especially hard. Early treatment of remaining healthy ash trees costs $300 to $600 per tree and takes one to two hours; removal of a dead 15-metre ash runs $1,200 to $2,500 depending on access and proximity to structures.

How We Treat Ash Trees Attacked by Emerald Ash Borer

Our assessment begins with a close visual inspection of the trunk, lower branches and root collar. We look for the distinctive D-shaped exit holes (about 3 mm wide), vertical bark splits where larvae have tunnelled, and crown symptoms such as branch dieback starting at the top. If we confirm active infestation, we discuss whether the tree is worth saving based on its size, health, location and your long-term plans for the property. A tree with less than 50 per cent crown loss and good structural form is a strong candidate for injection.

• Measure the tree diameter at breast height (1.3 metres) to calculate the injection dose.
• Prepare the injection sites on the trunk, typically two to four points depending on tree size.
• Inject TreeAzin or emamectin benzoate into sapwood using specialized equipment that delivers the product under pressure.
• Seal injection wounds with wound dressing to prevent pest and disease entry.
• Schedule follow-up inspections in autumn and the following summer to confirm the beetle population has declined.

The injection protects the tree for one to two years. We recommend annual re-treatment to maintain immunity until the emerald ash borer population in your area declines significantly, which may take many years. Visit our ash tree removal service page if you decide removal is the better choice.

Real example: A Mississauga homeowner had two 18-metre ash trees showing early EAB signs in June 2023. We injected both for $850 total. One year later, no new exit holes appeared and the canopy remained full. Removal of two trees that size would have cost $2,500 to $3,500. Treatment bought time and saved the landscape.

Treatment Methods and When Each Works Best

Treatment timing is critical. The emerald ash borer injection window in Toronto runs from late May through early July, when beetles are actively laying eggs and the tree's vascular system is moving water and nutrients upward fastest. Injection outside this window is less effective. Our arborists schedule treatments well in advance to secure your spot during peak season.

Regulatory and Safety Considerations in the GTA

The City of Toronto does not currently require a permit for emerald ash borer treatment on private property, as the work does not involve tree removal. However, if treatment fails and the tree must be removed later, you will need a permit for many ash removals, and the application is normally supported by an arborist report and risk assessment. Rules vary across the GTA, so we confirm local requirements before any work begins. If your ash tree stands near a hydro line, we maintain safe approach distances from your private electrical service entrance, respecting Toronto Hydro's clearance standards. We never touch the public distribution network. All our crews carry full liability insurance and document the treatment in writing so you have a record for your property file.

When we inject, we use certified applicators and follow label instructions precisely. The chemicals we use are registered with Health Canada and approved for use in in Toronto and the surrounding area. We seal injection wounds to prevent disease entry and clean up all debris. If you plan to sell your home, disclose the EAB treatment history to the buyer, as it demonstrates proactive tree care and may support the property's value.

When Treatment Beats Removal

Not every ash tree is worth saving. A tree with advanced crown loss, deep root rot, or a history of storm damage may be a better candidate for removal and replacement. However, a healthy 20-metre ash with good form and early EAB signs is almost always worth treating. The cost difference is dramatic: one injection treatment costs $300 to $600 and takes a few hours; removal, stump grinding and site cleanup cost $1,500 to $3,000 and tie up your yard for a day. Over a three-year period, you may spend $900 to $1,800 on annual treatments, still less than one removal. If the tree survives to year four or five without new EAB activity, you have essentially saved it. Contact us at (437) 600-1089 for an honest assessment. We will never push you toward removal if treatment is the right choice, and we will never recommend treatment for a tree that is too far gone.

Our crews work across Toronto, Mississauga, Brampton, Vaughan, Markham, Richmond Hill and surrounding municipalities. We have treated hundreds of ash trees since 2015 and understand the nuances of EAB biology and local beetle pressure. Whether your ash is in a ravine lot near the Don River, a tight backyard in Etobicoke, or a front yard on a busy street in Vaughan, we have the equipment and expertise to inject safely and document the work. Call us or visit our contact page to request your free estimate today.

Prices Emerald Ash Borer Treatment in Toronto — Indicative pricing

Indicative prices; free, personalized estimate within 24h at (437) 600-1089.