Property law: If a tree stradles two properties...

If a tree is right on the property line between two neighbors, can one neighbor decide to unilaterally cut it down? Would the tree loving neighbor have any right to sue?

You’ll need to look at your local law. And I am far from an expert. But my understanding in my jurisdiction is that both own the tree, and neither has the right to take any action that would kill the tree. Either party can trim or do anything else on their side of the tree that does not kill the tree.

And, yes, I imagine the tree lover would have the right to sue the neighbor who cut it down - tho I imagine calculating damages would be interesting.

This will almost certainly be covered by municipal law, so you’re probably not going to get any useful answers here. Call your local city hall (or the equivalent) and ask them.

IANAL, but what Dinsdale says here is what I remember from encountering ((not as a part-tree-owner) this circumstance in the past.

I’ve actually be subjected to this. We live in a townhouse and have a tree that is mostly on our property. Our neighbor doesn’t like the tree at all and wanted us to cut it down. Since we didn’t she cut every branch off her side. It’s still standing 4 years later, but when I called the city office they said she could do whatever she wanted to the tree parts that were over the line. I never did figure out if she could have cut half the tree down or not, but I think they said it would be our problem if the tree died.

Under municipal laws here, if the tree is over 12" in diameter, you have to get the city’s permission to cut it down also. So I’d imagine that if one neighbor didn’t want it cut down, the city wouldn’t be all gung-ho to approve its removal unless it was diseased or representing a hazard.

(Yup, we’re cutting down a tree in our yard.)

I think in some jurisdictions, one party is allowed to unilaterally cut down the tree if it’s damaging other aspects of the property, like roots growing into foundations or water lines.