Do Herbaceous Perennials Bloom More Than Once a Year?
Plants are categorized as herbaceous perennials if they live for more than two years, have soft, non-woody stems and go dormant during the winter. Although some herbaceous perennials will bloom more than once each year, this is not a distinguishing characteristic. With careful plant selection and proper maintenance, herbaceous perennials can create long-lasting color.
Herbaceous perennials typically have one specific bloom season such as early spring and late summer. Some perennials are described as continuous bloomers because their bloom season is extended over several months. However, even these long-lasting bloom seasons typically have a peak bloom time when flowering is the most profuse.
Continuous Perennial Blooms
Goblin blanket flower (Gaillardia x grandiflora "Goblin") is an herbaceous perennial that can bloom in various colors from late spring through fall. It is recommended for U. S. Department of Agriculture plant hardiness zones 3 through 10. Dahlias (Dahlia spp.) also produce flowers in a variety of colors beginning in early summer and lasting into winter. Dahlias can be grown successfully in USDA zones 9 through 11. Pincushion flower (Scabiosa columbaria) has blue and lavender blooms that appear from spring through fall in USDA zones 5 through 9.
Other Types of Repeat Color
In lieu of searching for herbaceous perennials that will repeat their bloom season in a single year, you may opt for selecting a plant that displays color in the off-season through other ways. Blue star (Amsonia tabernaemontana) has blue flower clusters in the spring or summer, followed by attractive foliage in the fall. Although the blooms aren't repeated for more than a season, the foliage makes up for it with the additional color. It is hardy in USDA zones 3 through 9.
Encouraging Blooms to Repeat
For herbaceous perennials with an extended bloom season, simple maintenance can be done to get the most out of the flowering period. By removing spent flowers, the plant is able to redirect energy toward new blooms and growth. This may allow the plant to re-bloom throughout the growing season and extend the bloom period.
- National Gardening Association: Repeat Blooming Clematis
- National Gardening Association: Getting Started with Garden Perennials
- National Gardening Association: Blue Star
- University of California Master Gardeners of San Mateo and San Francisco Counties: Plant Highlights
- University of California Master Gardeners of San Mateo and San Francisco Counties: Great Plant Choices
- University of California Agriculture and Natural Resources: Dahlia
- National Gardening Association: Scabiosa Columbaria "Butterfly Blue"
- National Gardening Association: Dahlia
- National Gardening Association: Gaillardia x Grandiflora "Goblin"
- Missouri Botanical Garden: Amsonia Tabernaemontana
Cynthia Domenghini holds a Ph.D. and bachelor's degree in horticulture, as well as a master's degree in teaching. She spent several years researching health outcomes of school gardening and has written numerous youth garden curricula and activity guides. Domenghini also served as an education specialist for the National Gardening Association.