Who Owns a Tree on the Property Line in Ontario?

In Ontario, a tree whose trunk grows across the property line belongs to both neighbours. Section 10 of the Forestry Act makes it common property, and injuring or destroying it without the other owner’s consent is an offence. If the trunk sits entirely on one side, the tree belongs to that owner, even if the branches and roots reach next door.

What Counts as a Boundary Tree

The test is the trunk at ground level. If any part of the trunk crosses the line, it’s a boundary tree. Branches hanging over the fence don’t make it shared, and neither do roots under your lawn. A tree planted a metre inside your neighbour’s yard is theirs, however much of it shades your side.

On older Woodbridge and Thornhill lots, a lot of mature maples and spruces were planted along the fence line decades ago. As the trunks grew wider, many of them crossed the line.

Find the Line First

Your property survey shows the line. Fences are often built a little to one side of it, so the fence alone doesn’t tell you who owns the tree. If you can’t find your survey, look in the papers from your purchase or ask the lawyer who handled it. If the stakes in the ground are gone, an Ontario land surveyor can mark the line for you.

Removing a Shared Tree

You need your neighbour’s consent to remove a boundary tree, or to cut it in a way that would seriously damage it. Get that consent in writing before any work starts. A short note signed by both of you, naming the tree and the work, saves arguments later.

You also need a City of Vaughan permit if the tree is 20 cm or wider, the same as any private tree. The City expects every owner’s consent on a shared tree. Read the Vaughan permit rules for how that works.

Roots Across the Line

Roots from a tree next door often grow under your lawn, patio or driveway. Cutting large roots can kill a tree or make it unstable, and that counts as damaging it. If roots are lifting your interlock or pushing on a wall, talk to your neighbour and get advice before anyone cuts. A root that injures a protected tree can also bring the Vaughan permit rules into play.

Sharing the Cost

The Forestry Act doesn’t decide who pays. Most neighbours split the cost of removing a shared tree. When we quote a tree removal on a boundary tree, we’re happy to walk the yard with both of you, so everyone hears the same plan and the same price.

Trimming a Shared Tree

Light trimming that keeps a shared tree healthy is less of an issue than removal, but it’s still wise to agree on it first. Heavy cutting that injures the tree needs your neighbour’s consent, and a Vaughan permit if the tree is 20 cm or wider.

When You Can’t Agree

If your neighbour won’t agree, you can’t remove the tree. Start with a conversation about what worries you, whether it’s the lean, dead limbs or roots lifting the patio. Sometimes a trim fixes the problem and nobody needs to lose the tree. If the tree is a real hazard, an arborist’s written opinion gives you both something solid to look at. Past that point, talk to a lawyer before anyone cuts.

A Tree That Is Only Yours

If the trunk is fully on your side, the tree is yours to look after, and the permit rules still apply. Your neighbour may trim branches that hang over their side, back to the line, as long as they don’t kill or seriously damage the tree. If a tree on your side is dead or dropping limbs into the yard next door, have it looked at before a limb lands in their yard.