What’s an Annual? What’s a Perennial?
What’s an annual?
The flowers that we plant for seasonal color are primarily annuals. These plants last for one season only. There’s a reason for that. Because they bloom so heavily, and give their all for a glorious, colorful show, they’re done by the end of the season. In California, the seasons for annuals overlap, but generally, there are “cool-season” annuals for October into March, spring annuals that flower March through June, and summer annuals for the hot months of July – October.
Top cool-season annual flowers are pansy, viola, stock, poppy, primrose and snapdragon. Favorites for spring are calibrachoa, lobelia, alyssum, petunia, diascia and nemesia. For hot summer annuals, plant vinca, pentas, sunflower, cosmos and zinnia.
What’s a perennial?
Perennials are plants that bloom for a shorter period of time (usually up to six weeks) then go into a resting period for the rest of the year. However, each year they will reappear to bloom, usually on larger and larger plants, giving an increased flower show each year. (Lily-of-the-Nile is a popular example.) There are some very long-blooming perennials for California gardens, such as geraniums (ivy types bloom almost all year), as do Spanish and Fernleaf lavenders and lantana.
Some plants commonly grown as annuals in cold climates are grown as perennials here, such as zonal geraniums. In California, if you plan well, you can have perennials blooming every month of the year.
What’s a biennial?
There is a third type of flowering plant called biennial. This is a much smaller group of plants. Biennials flower the second year of life, then they are through. However, they often re-seed (grow on their own from their own seeds). Once this cycle begins, you’ll have flowers every year. Examples of biennials are foxgloves, sweet William and hollyhocks. Breeders have recently introduced biennials that bloom the first year.
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