Last Updated: August 24 2026
In Ontario, when can a tree owner or contractor be liable after a branch falls?
Marketing.Legal™ can help Ontario tree owners and maintenance contractors understand liability risk and how to manage marketing that attracts the right legal audiences, because in negligence claims a plaintiff usually must show the occupier owed a duty to keep people and property reasonably safe under the Occupier’s Liability Act, R.S.O. 1990, c. O.2, and that the owner or responsible party knew or should have known of a dangerous tree condition and failed to take reasonable care; generally liability is not automatic just because a limb fell, as reflected in Hallok v. Toronto Hydro Electric System Ltd., 2003 CanLII 8519 at para 14, and after storms courts may find constructive knowledge through reasonable inspection practices, so it helps to document inspections, notices, and maintenance actions and ensure any contractor scope is clear before seeking liability-focused guidance or a safer risk plan; if you want a lawyer- and paralegal-focused digital marketing strategy for your practice or business, call (800) 551-5751.
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Liability Involving Tree Maintenance
The value and benefits of trees are often overlooked and the potential liability risks associated with trees are often underestimated or misunderstood. It is important for owners, contractors, and other individuals to take due care of trees so to minimize the potential for trees to cause injury or damage and thus to minimize the potential liability risks.
Note: Please contact Marketing.Legal™ by phone at: (800) 551-5751 to discuss any specific questions that you may have.
The Law
Duty of Care
The basic principles of common law, particularly negligence and the legal test regarding duty of care as founded within the Donoghue v. Stevenson case (a general principles case rather than tree specific case), prescribe that property owners owe a duty to ensure that other persons and the property of others persons is reasonably safe. In Ontario, these duties are also codified the Occupier's Liability Act, R.S.O. 1990, c. O.2, whereas it is said:
3 (1) An occupier of premises owes a duty to take such care as in all the circumstances of the case is reasonable to see that persons entering on the premises, and the property brought on the premises by those persons are reasonably safe while on the premises.
Negligently Performed Maintenance
Owners of trees, or others responsible for trees (such as hired maintenance contractors), generally face liability only when it was known, or constructively known, that a tree failure risk was present and the owner (or others) failed to properly tend to the tree. In this way it can be thought that the injury or damage was a result of delay in caring for the tree rather than the result of risks inherent in a tree. Essentially, the negligent failure to maintain is a man-made risk rather than a natural tree risk. On the point of liability for failure to maintain trees, such was addressed within the case of Hallok v. Toronto Hydro Electric System Ltd., 2003 CanLII 8519, wherein it was said:
[14] It would appear to be common ground that a property owner, such as Park Lawn, cannot be held responsible for damage resulting from a limb on a tree falling simply on the basis that the limb or tree fell. If the evidence does not establish that there was knowledge on the part of the defendant, Park Lawn, of a dangerous condition of a tree or that there was a dangerous condition of which the defendant Park Lawn ought to have knowledge, a finding of negligence is unavailable as a matter of law. (See: Culley v. Maguire, [1957] O.J. No. 52 (C.A.) at p. 1; Quinlan v. Gates, [2000] O.J. No. 5292(S.C.J.) at p. 2; Buttoni et al. v. Henderson et al., 21 O.R. 309 (H.C.J.) at p. 371; Doucette v. Parent, [1996] O.J. No. 3493 (Gen. Div.) at p. 4; Gasho v. Clinton (Town), [2001] O.J. No. 4505 (S.C.J. (Small Claims) at p. 4).
Accordingly, it appears that some level of awareness by knowledge, or constructive knowledge, of a dangerous condition is required if liability is to arise for negligence in the ownership, care, or control, of a tree. It is notable that "constructive knowledge" means knowledge that the law imparts upon a person who ought to actually hold knowledge based upon reasonableness principles; and as such, if a reasonably acting person would know of about a dangerous condition such is "constructive knowledge" and proving actually held knowledge is unnecessary. In many circumstances, proving constructive knowledge is much easier than proving actually held knowledge. As an example, following a severe storm, a court may deem that reasonably acting property owners would inspect trees for broken branches among other dangerous conditions. In this regard, it is important to note that intentionally avoiding the inspection of trees, among other things, and thereby choosing to remain ignorant of a dangerous condition may be deemed an act from which constructive knowledge is imposed.
Conclusion
Tree owners, or other persons who are hired to provide the care and maintenance of trees on behalf of the owners, are prescribed by law with a duty of care to reasonably ensure that the trees are maintained in a safe condition. If a person becomes injured or if property becomes damaged by a unreasonably maintained tree, liability may arise.
