Annual and perennial flowers perform differently in the landscape, but each is uniquely useful for home gardening. The main differences between the two types of plants are in the life cycle length, flower production, and required maintenance.
Annual flowers perform the miraculous feat of growth from a seed to a fully flowering adult plant in one growing season. This compressed life span makes annual plants an extremely powerful tool in landscape design. Annuals grow quickly, rarely lose foliage and produce long-lasting flowers. Perennials work quite differently than annuals, because these plants return each spring for three or more years. Perennials produce foliage as soil temperature warms and produce blooms for a short period of time.
Annuals mature from seed and produce foliage as a seedling. These plants must reach maturity quickly during this limited growth period. As a result, even the smallest annuals feature tiny flower buds. Mid-spring nursery offerings include those plants with buds or small blooms. Planting the annuals in well-drained organic soil helps foster the brilliant array of colors featured among many types of annual flowers. Perennial flowers appear for a two- to three-week period of time and then disappear for the remainder of the growing season. These flowers feature wonderful color variety and often serve to attract bees, butterflies and birds. Annual flowers last considerably longer than perennials and often fill in the gaps in garden beds between blooming periods of established perennial flowers.
Annuals and perennials both offer great versatility in the home landscape. Both types work well in container gardens and as accent landscape plants for shrub gardens. Annuals tend to be considerably smaller in stature than perennials and almost always are planted in groups of three plants to increase visual impact in the garden. Perennials can easily stand alone, forming a beautiful foliage shrub with the added benefit of a specific bloom time. Perennial roots lie deep in the soil long after annual plants have died from the first good frost. Perennial foliage can withstand a few rounds of frost before succumbing to the colder temperatures. Choose perennials based on foliage and desired flowers for this reason.
Annuals require gardeners to replant specimens every year, while perennials reappear on their own in the spring. Annuals also require deadheading to remove spent flowers to prevent the plant from wasting energy in seed production. Spindly annuals require pruning to promote new growth. Perennials require pruning after flowers fade to remove dead blooms and to limit excessive foliage growth. Perennial flowers also tend to expand in the garden with maturity and require division every three to four years to provide plenty of room for optimum growth.