Like old friends who arrive on your doorstep when you need them most, perennial plants reemerge from the earth just in time to fill in gaps after spring bulbs finish blooming.
Flowering perennials are the backbone of any garden. (Skip to the plant guides.) Most perennials a natural life cycle: Perennial plants die back in cold weather, then sprout again next spring, and the spring after that, and the spring after that. (What sets perennial plants apart from shrubs—which may also be perennial—is that garden perennials are herbaceous; shrubs typically have woody branches.)
Not all perennials are created equal. Some have a brief bloom season and others flower for months. Short-lived perennials such as poppies, lupines, or columbines may die after two or three years. Dutch master garden designer Piet Oudolf, famous for his painterly landscapes of mixed perennials, favors hardier, long-lived perennials such as salvias, Veronicastrums, asters, and Monardas.
Read more at Everything You Need to Know About Perennials.