By definition perennials are plants that continue to bloom year after year. Annual plants only bloom once in a season, and biennials bloom every other season. Perennials are by the far the most popular of plants for most gardeners due to their ease of care and the colorful rewards. Also, perennials have many diverse cultivars, selecting them can be a challenge. Perennials begin blooming in the spring and finish as the snow hits the ground in late fall. A well selected perennial garden will allow you to have depth and variety as well as an abundance of color blooming for many of the seasons.