It's hardy to Zone 2 , it's just one of those plants that if dumped somewhere will out compete others and take over. it is easy to keep in control if you careful to contain it a couple of times a year when you see it getting out of bounds. I love using it in containers or raised gardens where it can not get away from me.

I've had it for many years and only had one reseeded plant from it. So, no, i wouldn't call it noxious!