Mints are perennial herbs that are known for spreading aggressively. To prevent them from taking over a garden, grow them in a container about 12 to 16 inches in diameter. Runners (stolons) can be cut as needed if they try to creep out of the pot. As an alternative, grow mint in a bottomless container (remove the base of a utilitarian plastic pot) and plant the container into the ground, leaving about an inch of the container above the soil line. This forces the runners up and over the container lip where they can be seen and trimmed off before they root into soil on the other side.
Peppermint
Peppermint (Mentha piperita) produces upright stems about 2 feet or more in height. Dark green leaves and reddish stems have a characteristic warm, spicy scent. Tiny purplish flowers appear in dense terminal spikes 1 to 3 inches long.
Growing conditions for peppermint
Peppermint grows best in a rich, moist soil, but adapts well to most growing conditions. Propagate by division (splitting a mature plant) or cuttings (rooting stem or stolon clippings). The plant will grow in sun or shade, but will probably be at its most productive in full sun. Space plants 18 inches apart.
Harvesting and using peppermint
Regular or frequent harvesting encourages bushy, full growth. Use fresh leaves at any time. Leaves to be dried are best taken just as flowers begin to appear.
The leaves are used in tea and for flavoring other foods. Oil from the plant is used in products such as chewing gum, confections, toilet water, soap, and liqueur.
Spearmint
Spearmint (Mentha spicata) produces pointed, slightly crinkled leaves that are lighter green in color than peppermint. The whole plant has a characteristic sweet smell.
Growing conditions for spearmint
Spearmint grows best in a somewhat moist soil and full sun to part shade. It can be propagated by cuttings or division. Regular or frequent harvesting encourages bushy, full growth. Space plants 18 inches apart.
Harvesting and using spearmint
Pick the fresh leaves and leafy stem tips for use any time. For drying, it is best to cut leaves just as flowering begins.
Spearmint leaves are used to flavor teas, cold drinks, and to make mint sauce. The oil is used in confections.