Who owns a tree on a property line in Ontario?

In Ontario, Canada, who owns a tree on a property line is governed by common law, the Ontario Forestry Act, and municipal bylaws, and ownership depends on where trunk is located. Under Ontario law, if a tree trunk is entirely on one property, that property owner owns the tree, even if branches overhang neighbor. If tree trunk straddles the property line, meaning part of trunk is on each side of boundary, it is considered a boundary tree or shared tree under common law, and both property owners share ownership as tenants in common. According to Ontario courts, a boundary tree is jointly owned and neither owner can cut down, injure, or destroy it without consent of other owner, and doing so can result in liability for damages under Forestry Act and trespass. The Forestry Act Section 10 states boundary trees cannot be cut without permission of all owners. If tree is jointly owned, both owners share responsibility for maintenance and liability if tree falls. If branches or roots encroach, neighbor can trim up to property line but cannot kill tree. Disputes over boundary trees are common in Ontario and often require arborist to determine trunk location and surveyor to determine property line. Municipalities like Toronto have additional tree protection bylaws requiring permits to cut trees over certain diameter. So in Ontario, tree on property line with trunk on both sides is jointly owned, requiring mutual consent for removal, and ownership is shared.