I know many, many gardeners who recoil at the offering of a mint plant. It’s undeniable that mint will spread as far and as fast as its roots can travel, but that’s not all bad. Mint in the vegetable garden can be an ally in pest control.
Where Mint is Welcome
Mint and tomatoes have a mutually good effect on each other. The flavor and vigor of both plants is improved by growing them as neighbors. You could use mint as a living mulch, if you don’t mind doing some pulling, to keep it in check. Or…
…you could go the safe route and sink a potted mint plant, with the bottom of the container cut off, nearby the tomatoes. Eventually the roots will move out of the container, but if you lift it periodically and trim them, you should be able to keep them in check.
Where Mint Earns Its Keep
Mint has a similar effect on cabbage AND it deters the white cabbage butterfly from laying its eggs. (It even deters clothing moths indoors and smells a lot better than moth balls.)