When a tree looks dangerous in Toronto, the right first call depends on one thing: who owns the tree. If it is on City property, a boulevard, a park or public land, call 311 and report it to Toronto Urban Forestry. If it is on your private property, call an ISA certified arborist. Those two paths are different in every way: who responds, how fast, what they can do, and what it costs you.
Toronto Urban Forestry manages the City's street trees, park trees, and trees on City-owned land. If you have a concern about a tree in the boulevard strip between the sidewalk and the road, a park tree leaning toward homes, or any tree on clearly public land, calling 311 is the right starting point. Urban Forestry will log the complaint and schedule an inspection.
The important caveat is that this process is not immediate. Inspections are triaged based on complaint volume, and a non-emergency concern about a leaning street tree might take weeks to receive a site visit. If the situation looks immediately dangerous, tell the 311 operator it is urgent and request escalation. For active emergencies involving fallen trees on City property, Toronto's emergency line is available around the clock.
Urban Forestry has authority to order work on City-owned trees and can require adjacent property owners to take action where a private tree poses risk to public safety. However, the City does not manage trees on private residential property unless a formal complaint process results in a work order for a dangerous private tree that poses a hazard to the public right-of-way.
If the tree is on your property, the City is not coming to assess it, manage it, or pay for its removal. That is your responsibility entirely. The right first step is an ISA certified arborist site assessment, which gives you a written professional opinion on the tree's structural condition, failure risk rating, and recommended action. This is not the same as a tree service company coming to quote a removal. A formal risk assessment applies the ISA's documented methodology and produces a report you can use for permit applications, insurance purposes, and neighbour disputes.
When our arborist conducts a hazard assessment in Toronto, we examine the tree's structural condition from base to crown. We look for the main failure indicators: root plate problems, trunk decay, large dead branches, co-dominant stem conflicts with included bark, previously failed branch stubs, fungal growth indicating internal decay, and any visible cracks or splits in the main stem or scaffold branches. We then rate both the likelihood of failure and the consequence of failure based on what is in the target zone beneath the tree.
Signs a tree needs an urgent professional assessment:
The International Society of Arboriculture's tree risk assessment methodology rates trees on two independent axes. The first is the likelihood of failure, which accounts for the specific defects present, their severity, and the tree's overall structural condition. The second is the consequences of failure, which accounts for the size and weight of the likely failure, the target zone below (what or who would be hit), and how frequently that target zone is occupied.
A very large tree with significant decay over an occupied children's play area rates very differently from the same tree over an unused corner of a yard. The combined risk rating drives the urgency and type of recommended action. Low risk trees may need monitoring on a scheduled cycle. Medium risk trees typically need specific structural work to reduce the failure likelihood or remove the target. High and extreme risk trees need immediate action.
Our written reports follow this methodology and produce a formal risk rating that carries professional weight with the City's permit reviewers, with insurers, and in any subsequent civil dispute about the tree's condition.
A hazard assessment that supports removing a tree is also among the strongest possible bases for a Chapter 813 permit application. The City of Toronto's Urban Forestry reviewers take formally documented hazard assessments seriously. Applications accompanied by a proper ISA-methodology risk assessment report with a documented high or extreme risk rating are typically processed more smoothly than standard permit applications.
If you have a tree that qualifies as hazardous, the assessment and the permit application can be initiated simultaneously. Our arborist prepares the hazard assessment, and we use that same documentation as the foundation of the Chapter 813 permit report. You are not paying twice for two separate documents. The hazard assessment is the permit report for a tree that qualifies under the dangerous pathway.
For more on the permit process, see our complete guide to Toronto tree removal permits. For the specific process when the tree is already dead, see our dead tree removal permit guide.
Our ISA certified arborists conduct formal risk assessments using ISA methodology, producing written reports accepted by Toronto Urban Forestry for permit applications. We serve all Toronto neighbourhoods, North York, Etobicoke, Scarborough and the surrounding GTA. For urgent situations, call directly.
If you believe a tree on a neighbouring private property poses a danger to your home or family, your options are more limited but not nonexistent. The first step is to notify your neighbour in writing, with specific details about the concern and a request that they have the tree professionally assessed. Keep a copy of that communication with the date recorded. This creates a paper trail that matters if the tree eventually causes damage and you need to pursue a claim.
If your neighbour is unresponsive or denies the problem, you can file a 311 complaint asking Urban Forestry to inspect the tree as a private property hazard that threatens the public. Urban Forestry has authority to order work on private trees that endanger public safety. This process is slow and not guaranteed to produce results on your timeline, but it does create an official record of the reported concern.
For the civil dimension of neighbour tree disputes, including rights to trim overhanging branches and claims for damage already caused, see our guide to neighbour tree rights in Toronto.
A hazard assessment report gives you a clear picture of the situation and a professional recommendation. From that point, the path forward depends on the risk rating and the tree's specific conditions. Some trees need immediate removal. Some need structural pruning to reduce the failure likelihood or remove specific high-risk branches. Some need cable installation to support a compromised co-dominant stem. Some need monitoring on a defined cycle with a follow-up assessment in six or twelve months.
Whatever the recommendation, you now have it in writing from a credentialed professional. That document protects you with your insurer, with your neighbours, and with the City. And if the recommended action is removal, we handle the permit application as the next step without delay.
What is the difference between a tree assessment and calling 311 in Toronto?
Calling 311 about a tree on City property triggers an Urban Forestry inspection. That process can take weeks and does not apply to trees on your private property. An arborist assessment is a professional evaluation of a specific tree that produces written findings and a risk rating within days. If the tree is on your property, 311 is not the right call. If it is on a neighbour's boulevard or City land, 311 is appropriate but not immediate.
How long does a dangerous tree assessment take in Toronto?
A site visit for a standard residential property takes 30 to 60 minutes. The written report is typically ready within 2 to 3 business days. For urgent situations where you need an assessment the same day, call directly and explain the urgency. We prioritize situations with active structural contact or visible imminent failure risk.
Can Toronto Urban Forestry force my neighbour to remove a hazardous tree?
Urban Forestry can inspect trees on private property following a complaint and issue a work order if the tree is determined to be a hazard. The process is not fast and enforcement timelines vary. If you have an imminent concern about a neighbour's tree, document it in writing to both your neighbour and the City. If you believe the situation is immediately life-threatening, contact emergency services.
What does an arborist risk rating actually mean?
ISA risk assessment methodology rates trees on two dimensions: the likelihood of failure and the consequences of that failure given what is in the target zone below. A tree with a high likelihood of failure but no targets nearby may be lower priority than a smaller tree with moderate failure risk directly over a deck or driveway. The combined risk rating drives the urgency of the recommended action.
Does a hazard tree assessment report help with a Toronto tree removal permit?
Yes, significantly. A formal hazard assessment that documents structural defects, failure risk rating and the target zone is strong supporting material for a Chapter 813 permit application. City reviewers take documented hazard assessments seriously and they often move applications to the front of the review queue. Our hazard assessment reports are structured to serve dual purpose as both a safety document and permit support.
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Do not wait for a storm to make the decision for you. Our ISA certified arborists provide same-week hazard assessments with written reports across Toronto, North York, Etobicoke, Scarborough, East York and the surrounding GTA.