Mints grow easily in moist, rich soils almost anywhere in the world. They prefer some shade, but will grow amply in full sun. To grow mint plants from seed, sow 1/8″ deep, barely covering with fine soil, and keep moist. Seeds will germinate in ten to twenty days. Mints are slow to develop during the first year, but be ready to fight them back the second year.
If your growing season is long, a light harvest may be possible during the first year, but generally it is best to wait. Usually harvesting is done just before the plant blooms. Cut the entire plant to an inch above the ground. Mints can be cut back two or three times a year, thus providing plenty for fresh use, freezing, or drying.
Different varieties of mint should be planted as far apart as possible, as true mints hybridize easily, cross-pollinating when in close proximity. The resulting hybrid combines the characteristics of both parent mints in a way that may not be favorable. If you grow both peppermint and spearmint, start them at opposite ends of the garden in order to maintain the integrity of both.
Irving Goodman, former Smith County Master Gardener
Texas A&M AgriLife Extension Service