Gardeners toss around the term deadheading when discussing flowering, but what does it mean? Deadheading is pruning to remove older, faded flowers from a plant. But why is this technique beneficial to the plant and useful to gardeners?
Extending the Seasonal Bloom
Annuals and perennials begin growing above-ground stems and foliage starting in the late winter and continue through spring. At maturity, the plants form flower buds that bloom, are pollinated, and produce seed. Under favorable conditions, the seeds germinate and grow into new plants. Most perennial plants have a defined bloom cycle, though some are repeat bloomers. Most annual plants bloom until seeds are produced. During seed production, flowering slows as the plant puts its energy into developing seeds.
So, how can gardeners help their plants “put on” more new blooms throughout the growing season; by deadheading, of course. Removing faded and spent flowers encourages plants to produce additional flowers rather than shutting down their blooming cycle for the season. Some annual flowers are self-cleaning and repeat bloom easily. However, many established perennials can be encouraged to bloom a second time by removing spent flowers and applying a light application of a slow-release fertilizer. Deadheading, in this instance, benefits gardeners by extending the flower bloom. For more information on growing annuals and perennials as cut flowers, see the HGIC Hot Topic, Grow a Cutting Garden.
Self-Sowing Seed, To Have or Have Not
Flowering plants, both annual and perennial, produce seeds to ensure the next generation of plants. True annual plants start from seed germination and end with seed production in one growing season. Perennial plants produce seed during the growing season but “die back” to the ground at the season’s end. The following late winter to spring, perennials resume growing from the remaining established roots and underground vegetative structures to produce a new above-ground plant. Whether from an annual or perennial plant, mature seeds can fall to the ground and “self-sow” to produce a new plant. If the gardener prefers for this to occur, then job well done and carry on. However, some gardeners prefer that plants grow in a specific location, so self-sowing seed is not desirable. In this instance, deadheading can help to limit self-sowing seed. Remove spent flowers to eliminate seed production and self-sowing. By deadheading before seed production, the plant puts its energy into new growth rather than into seed. Gardeners who wish to save and redistribute or store seed can deadhead plants to harvest seeds before they drop to the ground.
Sanitation, It Helps
Some gardeners prefer a tidy garden. Flowers that shed dead blossoms automatically to develop new blossoms are considered “self-cleaning”; however, not all plants do this. Sanitizing a garden space by deadheading provides two-fold benefits. First, deadheading “spruces up” the garden space when desired. A second benefit is that removing spent flower heads reduces the incidence of disease that can develop on decaying plant matter. Deadheading flowers also allows gardeners to scout for other disease and pest insect evidence on plant foliage while in the garden. A little garden sanitation goes a long way; as the saying goes, ‘An ounce of prevention is worth a pound of cure.’ Using deadheading as a sanitation technique to tidy up the garden space limits self-sowing seed and recycles energy into new blossoms for the next flower show.
Deadheading is not a complicated task. Gardeners can pinch off old flowers easily with fingers or use sharpened hand sheers or clippers to snip off spent flowers in their entirety. Wipe down pruning blades with rubbing alcohol between cuts as a safety precaution or if disease is suspected. Transferring disease to different plant parts or other plants is not a best management practice. Be sure to dispose of plant debris properly. As the growing season wanes towards fall and the impending frost, consider leaving seed heads in place to benefit wildlife. Seeds are a nutritious food resource for wildlife during winter when supplies become limited.