Experts and BHG readers answer.
What is the difference between the lifespan of an annual versus a perennial?
Gardening can be confusing to beginners-there's the challenge of figuring out what plant to grow where, along with new terms to learn. Perennials. These are plants that come back year after year from their root systems. Examples include bleeding heart (Dicentrat), purple coneflower (Echinacea) and hosta. Typically more expensive than annuals at the garden center, perennials are a good investment because many are long-lived. Plus, many get bigger every year, and after a couple of years you can split them. When grown from seed, most perennials will not bloom the first year, so they do require a bit of patience. Also, many perennials bloom only for a few weeks each season.
Annuals. These plants grow, bloom and die in one growing season. Examples include marigold (Tagetes), petunia and zinnia. Because annuals pack all their energy into one year, many bloom all season long. Biennials. This group of plants seems to be caught in the middle between perennials and annuals. They spend the first year of life as foliage plants. They come back a second year and bloom, then set seed and die. Examples include many foxgloves (Digitalis), and Canterbury Bells (Campanula medium).
Tender Perennials. Think of tender perennials as having a secret identity: in cold climates they're annuals, but in frost-free climates they're perennials. (Gardeners in cold climates may be able to keep some tender perennials alive over winter as houseplants.) Examples include lantana, coleus (Solenostemon), and geranium (Pelargonium).
Short-lived perennials. Some perennials do well only for a few years, then fade. Examples include some lupines (Lupinus), and columbines (Aquilegia). Many gardeners treat these plants as annuals, growing new ones from seed or purchasing new ones every year or so.
Self-sowers. These plants, which could be annuals, perennials or biennials, produce seeds if the spent flowers are not removed. The seeds drop and sprout easily in the garden- so you don't have to plant them again. Examples include gloriosa daisy (Rudbeckia), spider flower (Cleome), columbine (Aquilegia), and foxglove (Digitalis).