For instance, all plants are either annual, biennial or perennial . An annual completes its life cycle in a single growing season. Examples of common annuals are sweet alyssum, petunias, zucchini and tomatoes. A biennial completes its life cycle in two growing seasons. Examples of common biennials are English daisies, parsley and some types of foxglove.
Perennials are plants that live more than two growing seasons.
This includes the ornamental plants we commonly call perennials such as daylilies, peonies and coneflowers as well as all the trees and shrubs. The annuals, biennials and perennials are also divided into either herbaceous or woody categories. Herbaceous plants have soft, non-woody growth and they die back to the ground at the end of the growing season. Technically annuals are herbaceous but this term is generally reserved for plants that are perennial. Woody plants are those that develop bark, a thick, woody covering on their twigs and branches.