Annual & Biennial Plants

Flowers and plants are classified as annuals, biennials or perennials.

An experienced gardener knows the importance of the different categories of plant and flower varieties. The terms "annual," "perennial" and "biennial" refer to the unique growth patterns of plants, when they will bloom and when they can be expected to die. Knowing which cycle your plants are on will help you know when to expect a show of color in your garden.

Annuals

Vegetation classified as an annual means it will complete a full life cycle from seed to flower within the course of one season. These flowers will generally bloom from spring to fall, then all parts of the plant, including the roots, will die. Gardeners must replant these flowers and plants the following spring. Examples of annual flowers are petunias, daisies, zinnias and marigolds.

Biennials

Biennials are plants that need two years, or two full growing seasons to finish a full life cycle. The first season, the plant will show small growth, including a few leaves near the soil's surface. It is during the second season that the plant will mature and flower, and then die. If the plant finds itself in a suitable environment, its seeds may begin growth again the following season. Examples of biennial plants are pansies, foxglove, evening primrose and hollyhock.

Exceptions

Local climate conditions and geographic region can impact how a flower will grow. This influence can determine if a plant will grow as an annual or perennial -- a plant that returns each year. Plants that are perennials in warmer climates can be grown as annuals in colder climates. Examples include calla lilies, dahlias, agapanthus, tuberous begonias and caladiums.

References

• Texas A&M Extension: Wildflowers in Bloom
• University of Nebraska at Lancaster Extension: Fall Care for Tender Perennials