A perennial plant or perennial (Latin per, “through”, annus, “year”) is a plant that lives for more than two years.^[1] When used by gardeners or horticulturalists, applies specifically to winter hardy perennial herbaceous plants. Scientifically, woody plants like shrubs and trees are also perennial in their habit.

Perennials, especially small flowering plants, grow and bloom over the spring and summer and then die back every autumn and winter, then return in the spring from their root-stock rather than seeding themselves as an annual plant does. These are known as herbaceous perennials. However, depending on the rigors of local climate, a plant that is a perennial in its native habitat, or in a milder garden, may be treated by a gardener as an annual and planted out every year, from seed, from cuttings or from divisions.