Resources
Tree Risk Warning Signs
Find the sign you see on your tree below. Each one tells you whether to watch it, book an assessment soon, or keep clear and call now.
Track it over the coming weeks or seasons. No immediate action needed.
Have an arborist look at it before it gets worse.
Keep clear of the area and call an arborist now.
Canopy Thinning or Dieback
The canopy looks thinner than it did last year, but the tree still has healthy green leaves elsewhereMonitor
Minor thinning can follow a dry summer, a heavy seed year, or normal aging in an older tree. Watch it. No action is needed yet.
Whole branches at the top of the tree have no leaves while the rest of the canopy is fullGet an assessment soon
Dieback concentrated in the upper crown often points to a root or trunk problem restricting water and nutrients, even though the visible symptom is at the top.
More than half the canopy is bare, sparse, or carrying small, discoloured leaves during the growing seasonGet an assessment soon
Extensive canopy loss in season usually means significant internal decline. Combined with any structural defect below, a tree in this condition can fail with little warning.
Mushrooms or Fungal Conks at the Base
Fungal growth on the trunk, root flare, or surrounding soil.
Small mushrooms have appeared in the grass near the tree, not touching the trunkMonitor
Mushrooms in the surrounding soil are often feeding on buried wood, mulch, or old roots unrelated to the living tree. Note the location and keep watching the base of the trunk itself.
Shelf-like fungal growth (conks) is attached directly to the trunk or the root flare at the baseGet an assessment soon
Conks growing from the trunk or root flare indicate internal decay at that location. The extent of the decay cannot be judged from the mushroom alone. This needs a hands-on assessment, particularly if the tree stands near a house, driveway, or path.
Conks are present on a large tree that overhangs a house, driveway, deck, or an area where people regularly stand or parkStay away and call now
Decay fungus at the base of a tree with a target underneath it (a structure, vehicle, or place people gather) is one of the higher-priority situations in tree risk assessment. Trunk and root decay can progress well before any external sign appears above the conk.
Leaning, Especially After a Storm
The angle of the trunk relative to how the tree has always grown.
The tree has always grown at a slight angle and nothing has changed recentlyMonitor
Many trees develop a natural lean while young, reaching for light, and hold that angle for the rest of their life without issue. A longstanding, unchanged lean is a lower concern on its own.
The tree is leaning more than it used to, or the lean appeared suddenly after wind or heavy rainGet an assessment soon
A new or worsening lean, particularly one that shows up right after a storm, can mean the root plate has partially lifted or sheared. Soil cracking or heaving on the side opposite the lean is a specific sign to check for.
You can see soil lifting, cracking, or a gap opening at the base on the side away from the lean, or the lean has visibly increased in the last day or twoStay away and call now
This pattern points to active root failure. The tree can come down with little further warning. Keep people, vehicles, and pets away from the area until it has been assessed.
Cracked, Split, or Hanging Limbs
Damage to individual branches or major limb unions, not the whole tree.
A small branch, under about 5 cm thick, has snapped and is caught in the canopy aboveMonitor
Minor deadwood in the upper canopy is common and not urgent. Clear it before the next wind event knocks it loose.
A crack has opened along a major limb or where two large branches meet the trunk, but everything is still attachedGet an assessment soon
Cracks at branch unions, especially where the bark looks pinched or included rather than smoothly fused, indicate a structurally weak attachment point. These can fail under wind load without additional visible warning.
A large limb is broken, split, or hanging and only partially attached, especially over a driveway, walkway, or place people useStay away and call now
A partially attached limb over a target area is an immediate hazard. It can drop at any time, including in calm conditions.
Roots Cut or Disturbed by Construction
Excavation, trenching, grading, or equipment near the root zone.
Digging happened near the tree, but stayed well outside the drip line and no major roots were visibly cutMonitor
Work outside the critical root zone is lower risk, though soil compaction from equipment traffic can still affect a tree over the following seasons. Watch the canopy for changes over the next year or two.
A trench, footing, or grading cut severed roots thicker than about 5 cm, within a few meters of the trunkGet an assessment soon
Cutting major structural roots reduces both the tree's anchorage and its ability to take up water, and the full effect can take a season or more to show in the canopy. A tree in this situation should be assessed before deciding whether it is stable to keep, particularly if it stands near a house or driveway.
Heavy equipment worked directly over the root zone, a large section of roots was exposed or removed on one side, or the tree has started to lean since the work beganStay away and call now
Significant root loss on one side of a tree, combined with any new lean, changes how much weight the remaining roots can hold. Keep people away from the tree and call an arborist now.
A formal tree risk assessment rates the chance of failure
A tree risk assessment is a structured evaluation that follows the ISA's Tree Risk Assessment Qualification (TRAQ) methodology. Rather than a general opinion on tree health, it produces a written report rating the likelihood of failure, the likelihood something would be struck, and the consequences if it happened, combined into an overall rating of low, moderate, high, or extreme.
It is worth paying for one when a structural defect and a target line up: a tree with decay, a crack, or root damage standing near a house, driveway, or area people use. It is also the right document when an insurer, a lawyer, or a municipality specifically asks for formal risk documentation rather than a general health note.
Learn About Tree Risk AssessmentsIf a Storm Just Damaged Your Tree
Call 911 first if anyone is trapped or a structure was hit
If the tree came down on a house, garage, or a vehicle with someone inside, or if anyone is trapped, call 911 before anything else. Stay out of the damaged structure until emergency services confirm it is safe to enter.
Keep everyone clear of the tree and power lines
Keep people, pets, and vehicles away from the tree and anything it is leaning toward or hanging over, including power lines. If a limb or the whole tree is touching a line, treat it as an electrical hazard and contact the utility, not a tree service.
Document before anything gets cleared
Photograph the damage from multiple angles, including the base of the tree and any exposed roots, before cleanup starts. Your insurer will want these photos, and once debris is cleared, they cannot be retaken.
Get an independent opinion before the removal crew decides
After a storm, a debris crew that also does removal work has a stake in the removal call. An independent assessment, from a firm with no stake in whether the tree comes down, tells you what the tree needs.
Frequently Asked Questions
How do I know if my tree is dying?
Look for canopy thinning that concentrates in the upper crown, bark that no longer sits tight against the wood underneath, and a lack of new growth at branch tips during the growing season. A certified arborist checks the cambium layer and root flare directly and gives you a clear answer.
How do I know if my tree is dangerous?
A tree becomes a higher priority for assessment when a structural defect, such as trunk decay, a cracked limb union, or root damage, is paired with a target underneath it: a house, driveway, parking spot, or an area people use regularly.
Should I get a tree risk assessment or just an inspection?
A general inspection covers the tree's overall health. A formal tree risk assessment follows the ISA TRAQ (Tree Risk Assessment Qualification) methodology and produces a written, standardized risk rating that insurers, lawyers, and municipalities recognize. If you need documentation for an insurance claim, a legal matter, or a contested permit, a TRAQ assessment is the right tool.
What should I do if a tree looks dangerous after a storm?
If the tree came down on a house, garage, or a vehicle with someone inside, or anyone is trapped, call 911 first and stay out of the damaged structure until emergency services confirm it is safe to enter. Otherwise, keep people, pets, and vehicles clear of the area first. Photograph the damage for your insurer before anything is cleared away. Then get an independent assessment before agreeing to any removal. A crew that clears storm debris and also does removals should not decide what comes down.
Can I wait and see if the tree gets worse?
Yes, for symptoms in the monitor tier. Watch the tree over the next season. No, for anything in the "get an assessment soon" or "stay away and call now" tiers. Book the assessment.
Confirm Your Tree's Risk Tier
We do not perform removals, so our answer has no sale behind it.
Related Resources
Get a Second Opinion Before Removal
Get an independent assessment before a tree comes down.
Read the guide →Tree Risk Assessments
Formal written risk evaluations prepared for insurers, legal counsel, and municipalities.
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How the difference affects your report and your permit.
Read the guide →Tree Removal Reports
Permit-ready arborist reports if the assessment confirms removal is the right call.
Learn more →Permit Rules for Dead Trees
How the dead and hazardous tree exemption differs across 21 GTA municipalities.
Read the guide →Neighbour Tree Disputes in Ontario
Who is responsible when a hazardous tree sits on or near a property line.
Read the guide →Get a quote
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