Definitions of Annual, Biennial, Perennial, and Ephemeral
AnnualsAnnuals are plants that go through their entire life cycle in one growing season.
Hardy annuals are plants that go through their entire life cycle in one season and that can be sown outside in the open garden in spring where it is to flower, for example, Centaurea cyanus – cornflower.
|Centaurea cyanus - Cornflower|
Half-hardy annuals are plants that die if exposed to the cold, so they can’t go into the garden until after the last frost and should be sown indoors in spring. They’ll keep going until killed by the first autumn frost. For example, Tagetes erecta - African Marigold.
|Tagetes erecta - African Marigold|
Biennial are plants whose life cycle spans two years, so they flower and produce seeds in their second year. An example of a biennial is Armoracia rusticana - Horseradish.
|Armoracia rusticana - Horseradish.|
PerennialsPerennials are plants that live for more than two years.
Woody perennials are plants that exhibit secondary growth resulting in wood i.e all trees and shrubs such as Cornus mas - Cornellian Cherry
|Cornus mas - Cornellian Cherry|
Herbaceous perennial are non-woody plants that die back to a rootstock each autumn and regrow in the following spring. For example, Comfrey - Symphytum uplandicum or Narcissus poeticus - Daffodil.
|Comfrey - Symphytum x uplandicum 'Bocking 14'|
EphemeralsEphemeral plants can complete several life cycles in a growing season if correct weather conditions are present, for example, the delicious wild edible Stellaria media - Chickweed.
|Chickweed - Stellaria media|