Good fences make good neighbors, but when tree branches extend over those fences—or property lines—neighbors can become grouchy.
The most admired and sought-after natural specimens in the landscape, trees do more than provide soothing summer shade—they enhance curb appeal and increase the property's value if they're cared for. However, trees that grow on or near property lines can cause ongoing disagreement between neighbors, and in some cases, can lead to unneighborly feuds and lawsuits.
A tree near a property line belongs to the neighbor who owns the ground where it's growing. This is true even if the other neighbor planted the tree, so it's a good idea to have the property surveyed to determine the exact boundary line before planting border trees. Don't assume the boundary line lies where you stop mowing—it might be a few feet in either direction.
When a tree's trunk lies directly on the boundary line between properties, the tree is known as a boundary tree and is assumed as owned by both neighbors. In the case of boundary trees, both neighbors benefit by agreeing on how to care for the tree and share the trimming and care expenses. Both neighbors must consent to the tree's removal, and both hold legal responsibility for its care.
When branches from a neighbor's tree extend over the boundary line, the property owner has a right to trim the branches back—but only to the boundary line and no farther. Also, the trimming and pruning must not be so extensive that they kill the tree. If over-pruning leads to a tree’s demise, the heavy-cutting property owner could be legally liable for replacing the tree, which, in some cases, can run thousands of dollars.
Spreading roots of large trees can push down fences and cause curbs and sidewalks to heave and crack. When wandering tree roots damage a neighbor's property, financial liability for the damage falls on the tree's owner. A court—or in some cases, the local planning and zoning authority—might order the tree's owner to pay to remove the tree.
Healthy, well-maintained trees are less likely to break, and if a storm sends a limb from your tree through a neighbor's roof, you might not be liable if you can show that the tree was healthy when the limb broke. Courts (and insurance policies) might deem the damage an "Act of God." If, however, the tree was in bad shape and you failed to fix it, you might have to pay to repair the neighbor's property.
Hope this helps!