My first choice would be to talk to the owner about it. Maybe bring a 6-pack or a batch of cookies along.

If your neighbor is not amenable to conversation, you have learned several ways to get the deed done.

If you don't want to trespass, wait until they start sprouting on your side of the fence and then follow the kill method for hat happenstance.

Regards,

deadlift_dude
“The very first essential for success is a perpetually constant and regular employment of violence.”
----Fred Rogers