Spearmint (Mentha spicata) is a hardy, herbaceous perennial from the Lamiaceae family. Reaching heights of 1 to 3 feet, with a 1-to-2 foot spread, spearmint has multiple uses. With crinkled, ligh-green foliage and blooms in shades of lilac, white and pink, this flavorful herb adds color, character and flavor to herb gardens and flower beds, and makes an attractive ground cover for sore spots in the landscape. Seed, cuttings and division readily propagate spearmint, which prefers full sun and moist soil with a pH level of 6.0 to 7.0.
Keep soil moist during the growing season. Spearmint grows best with consistent watering, but not over-saturation. An inch of water per week is sufficient in areas with regular rainfall. In drier climates, water two to three times per week.
Add a 1-to-2-inch layer of mulch around the base of spearmint plants to retain moisture and add nutrients to the soil. A second layer should be added in the fall, before first frost, to protect plants throughout the winter.
Harvest new leaves in the morning, after dew evaporates, for highest flavor content. Pinch or snip off leaves at the top of the stem to encourage fuller growth, and to prevent plants from becoming tall and spindly.
Prepare spearmint plants for winter by cutting plants back, leaving 1 inch of growth above ground.
Cover plants with a thick layer of mulch (wood, straw, grass clippings) at a depth of at least 2 to 3 inches. This layer should be partially removed at the beginning of the next growing season.