The world of mint is much larger than most people think. Spearmint (Mentha spicata) and peppermint (Mentha piperita) come to mind, but there are 25 identified species and hundreds of varieties within each species. There are several different types of spearmint, the mint most commonly used in cooking, since it has a less intense flavor than peppermint. Most mint plants are hardy in United Stated Department of Agriculture Zones 3 through 8, though hardiness varies based on variety.