All types of mint (including sweet mint, spearmint, peppermint, and chocolate mint) are fast-growing, spreading plants, so you must give them a place to spread without getting in the way, or plant them in a large ceramic planter. Mint sends out runners that spread above and just below the ground, quickly forming large, lush green patches. In the right place it makes a pretty seasonal ground cover. You can also contain mint in tight places such as between pavers of a walkway where your feet will brush against the leaves to release its fragrance.
Because mint tends to take over, many gardeners plant mint in a small ceramic pot and then plant that pot in the ground or inside a large ceramic planter.
Plant mint in the spring, or in the fall in frost-free climates, setting seedlings 18 to 24 inches apart. The most popular way to grow mint is in a pot where you can keep it in check and handy near the kitchen for a constant supply of sprigs. Add water-retaining polymer to the potting soil to be sure that it stays moist.
In the ground, select a damp area in your garden in either full sun or part shade. Mint prefers fertile soil with a pH from 6.0 to 7.0. Mint is plenty vigorous on its own, but will appreciate a little fertilizer every few weeks, especially if you harvest a lot. Use Bonnie Herb & Vegetable Plant Food, which is low in salts and won’t cause leaf tips to brown. Keep the soil moist and mulch around the plant to keep its roots moist.
Keep plants in check by harvesting the tips regularly and pulling up wayward runners. Mint’s small flowers bloom from June to September; trim these before the buds open to keep the plant compact. Although slightly frost tolerant, the top of mint will eventually die back in winter except in zones 8 and south, but the root are quite hardy, surviving into zone 5 (some varieties even into zone 3). Lift and replant your mint every 3 to 4 years to keep your patch’s flavor and scent strong.