Coreopsis, also known as tickseed, is a favored addition to many gardens, offering cheerful, daisy-like blooms and a long season of color. Understanding proper pruning techniques helps these adaptable plants remain healthy, produce abundant flowers, and thrive throughout the growing season.
Why Pruning Coreopsis Matters
Pruning coreopsis benefits the plant’s health and flowering. Deadheading, the removal of spent flowers, encourages continuous new blooms by redirecting the plant’s energy from seed production. This extends the flowering period, allowing for a prolonged display of color.
Beyond flower production, pruning maintains plant vigor and shape. Regular trimming prevents coreopsis from becoming leggy or sprawling, promoting a bushier and more compact growth habit. It also improves air circulation within the plant, which can reduce the risk of certain fungal diseases. For some varieties, pruning helps prevent unwanted self-seeding, which can be useful if you prefer to control plant spread. An occasional extensive cutback can also rejuvenate older plants, stimulating fresh growth and renewed flowering.
When to Prune Coreopsis
For continuous blooming, deadheading should occur regularly throughout the flowering season, from early summer into fall, as soon as flowers begin to fade. Checking plants weekly helps ensure spent blooms are removed before they go to seed.
More significant cutbacks can be performed at different times. A major cutback, where plants are reduced by up to half their size, can be done in mid to late summer to encourage a fresh flush of fall blooms. For perennial coreopsis, an early spring pruning, just as new growth emerges, involves cutting back dead or woody stems to a few inches above the ground.
While some gardeners cut back perennial coreopsis in late fall for a tidy appearance, leaving the foliage intact over winter can provide insulation for the plant’s crown, particularly in colder climates. If cutting back in fall, it is recommended to leave at least 4 to 6 inches of stems for winter protection.
How to Prune Coreopsis
Always use clean, sharp pruning shears or scissors to make precise cuts, minimize plant stress, and prevent disease spread. For deadheading individual spent blooms, cut the stem just above the nearest set of healthy leaves or a new bud. This directs the plant’s energy towards developing new flowers rather than producing seeds.
For varieties with numerous small flowers, or when a large section of blooms has faded, shearing or mass pruning can be more efficient. This involves cutting back larger sections of the plant by up to half its height, encouraging a flush of new growth and a subsequent wave of flowers.
A major cutback can be performed in late summer or early spring. In late summer, after the main bloom flush, reduce the plant by one-third to one-half to encourage fall reblooming. For spring rejuvenation, cut back dead or woody stems to 4 to 6 inches from the ground as new growth begins to show. This promotes vigorous new growth from the base. When performing any cut, aim for a slight angle and cut well above any signs of disease. Always dispose of pruned debris properly, especially if diseased, to prevent pest or disease spread.
After Pruning Care
After pruning, especially following a significant cutback, water the plant well to help it recover. Consistent moisture supports new growth. Coreopsis generally prefers well-drained soil and is drought-tolerant once established.
Consider applying a balanced, light fertilizer if a large amount of plant material was removed, particularly after a major cutback or shearing. Coreopsis typically does not require heavy fertilization, as too much nitrogen can lead to excessive foliage at the expense of flowers. Monitor the plant for new growth and any signs of pests or diseases. In colder climates, if a fall cutback was performed, apply a 2 to 4-inch layer of organic mulch around the plant’s base for winter protection. Remove this mulch in spring once the threat of frost has passed to allow new growth to emerge.