Yea didnt notice the part about it being on othes land, I'd wager they wouldn't be real happy about it, you might approach them and see how they feel about it.
I quite assure you, you will have the opportunity to kill it soon tho, I'd spreads rampantly!
It'll ramble on the ground til it finds a good tree to go up, at that point it'll mature, make seed and quickly form a mat that nothing can grow they, and will choke out and survivors...
Crossbow is the only spray I know will kill it.
