Tree Liability Risk:

Question: Can I be held liable in Ontario if a tree on my property falls and injures someone or damages a neighbour’s property?

Answer: In Ontario, liability for tree-related injury or damage often turns on whether you knew or should reasonably have known the tree was unsafe and failed to take reasonable steps to inspect or maintain it, including under Occupier’s Liability Act, R.S.O. 1990, c. O.2.   Hall Paralegal Services provides Ontario paralegal services to help you assess potential exposure, gather evidence, and respond to claims related to tree maintenance and alleged negligence.

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.

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:

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:

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

The owners of trees, or those entrusted with the care and maintenance of trees on behalf of the owners, owe a duty of care to reasonably ensure that the trees are maintained.  If a person becomes injured or property becomes damaged by a tree that was improperly maintained, liability for the injury or damage may arise.