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

Although trees are extensively found throughout our urban and rural landscape, the value and benefits of trees are often taken for granted. Additionally, the potential liability risks are often unappreciated or misperceived. Owners and contractors, among others, should carefully heed the potential liability risks arising from the ownership, care, or control, of trees.

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

Generally, the owner of a tree, or other persons responsible for the care of a tree such as hired maintenance contractors, will be held liable for injury or damage caused by the tree only when it was known, or constructively known, that a tree failure risk was present and the owner, or other person, failed to take proper care of the tree. Accordingly, it should be viewed that the injury or damage resulted due to neglect in the care of the tree rather than as a result of inherent risks. Essentially, it is the man-made risk of negligent failure to maintain a tree rather than an inherently natural tree risk that is said to give rise to liability for injury or damage. On the point that liability arises for the negligent failure to maintain trees rather than being absolute so to include inherent risks, such concerns were addressed within the case of Hallok v. Toronto Hydro Electric System Ltd., 2003 CanLII 8519, wherein it was stated:

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.