Usually a boundary line tree is understood as the common property of both neighboring owners.  Neither of the land owners has the right to damage or destroy the tree without the other’s consent.   If any of the land owners are harmed in any way or threatened to suffer any damages by the boundary line tree, that land owner is entitled to remove the tree, or obtain a court order to remove the tree.

An adjoining landowner does not have the right to trespass on the neighboring land to cut down a tree even if the tree constitutes a nuisance.  In the same way, the adjoining property owner does not have the right to cut the trees down even where the trees lean over his/her property.

In Fick v. Nilson, 98 Cal. App. 2d 683 (Cal. App. 1950), a property owner and the neighbor owned adjoining lands. The roots of the property owner’s trees damaged the neighbor’s property.  The property owner’s predecessor permitted the neighbor to cut down these trees in the past, but the current property owner would not.  When the neighbor cut down the trees, the property owner brought suit. The court ruled that the property owner was entitled to compensatory damages. The Court also opined that while the evidence established that the trees caused damage to the neighbor’s property, giving rise to an action for damages and for abatement, it did not entitle the neighbor to take the law into his own hands.