A perennial plant or
perennial is a plant that lives for more than two years.
When used by gardeners or horticulturalists, applies specifically
to winter hardy perennial herbaceous plants. 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