Mel G told me she bought some bought a mint plant recently and asked if she could grow them outside and whether it could withstand cold climate.
According to Wikipedia, Mint(Mentha) is a genus of flowering plants in the family Lamiaceae.
Mint is aromatic. Mint prefer and thrive in cool moist spots in partial shades. Mine in the full sun! They are fast growing and multiply each year spreading through its runners. They are perennials meaning they do come back.
Instead of buying, you could actually pluck one out of your friends' or family's or even your neighbours' garden. All you need to do is, just pop them in the water. I did mine in little bottles like these. Of course the water colouring is optional. I just want to brighten up my colourless bottles.
Just after a few days, look at how fast the roots grow. It is that simple and free.