Hey all! I recently read about Mountain Mint, and I'm interested to know if Narrow Leaf Mountain Mint is as vigorous as regular mints, or is it more of a shrubby bush that's not going to take up half the garden. I'm really into herbs, and I saw a picture of it and it's so eye-catching! I'm just very wary of anything in the mentha family, as some are pretty invasive. It's supposedly zone 4, and would work for me where I live. Any help appreciated!