Annuals complete their entire life cycle in a year or less. In most cases, annuals are planted from seed in the spring, flower and set seed during the summer and early fall, and are killed by the first hard frosts of winter. Biennials take two years to complete their life cycle. When grown from seed, they produce leaves but no flowers the first year, the second year they flower, set seed, and die. Perennials live more than two years.
Many plants are perennial, including trees, shrubs, and bulbs.
The word perennial, as we use it here, refers to herbaceous flowering plants. Herbaceous means that the stems are soft and fleshy rather than woody like those of shrubs and trees. Bulbs, although perennials, are classified separately because of their method of storing food. The information written here is intended for plants grown for ornamental purposes. Visit the Vegetable section for information on edible plants.