We have ours in a raised bed and it is currently competing with our yarrow to see who can take over it first. I would recommend a pot or some way of containing anything in the mint family
Becky, mine thrives in full sun, zone 5 (sometimes 4) and babies pop up all over my rather extensive garden, some from underground, many from seed. I’m able to give away lots of plants and all of my friends and neighbors now have Lemon Balm in their yards as well.