Tickseed is a popular flowering plant known for its vibrant, daisy-like blooms that cover gardens from early summer through fall. It belongs to the Asteraceae family and is classified under the genus Coreopsis, which contains over 80 different species. Native to the Americas, Coreopsis is widely cultivated due to its tolerance for heat and its extended flowering period. The large number of species and hybrids makes determining its life cycle complex for gardeners.
The Definitive Answer: Perennial, Annual, or Tender?
Whether Tickseed is a perennial depends entirely on the specific species and the local climate where the plant is grown. The Coreopsis genus includes species that fit into all three common life cycle classifications: annuals, true perennials, and tender perennials. A true perennial is an herbaceous plant that lives for more than two years, with its top growth dying back in winter and regrowing from the roots the following spring.
Annual species, such as Plains Tickseed (Coreopsis tinctoria), complete their entire life cycle within a single growing season and must be replanted each year. Confusion often arises with tender perennials. These are plants that survive year after year in warmer climates but cannot withstand the freezing temperatures of colder regions.
A plant’s perennial status is determined by its tolerance to minimum average winter temperatures, referenced by the USDA Hardiness Zone system. For a Tickseed variety to be a reliable perennial, it must be rated for the gardener’s specific zone. If a plant rated for Zone 8 is planted in Zone 5, it will likely be killed by the cold and must be treated as an annual.
Identifying Reliable Perennial Tickseed Varieties
When seeking a plant that reliably returns each spring, gardeners should focus on specific perennial Tickseed species and their cultivars. Two dependable perennial species are Threadleaf Tickseed (Coreopsis verticillata) and Lanceleaf Tickseed (Coreopsis lanceolata). Threadleaf Tickseed is favored for its fine, airy, almost fern-like foliage that creates a soft texture in the garden.
Cultivars of C. verticillata, such as ‘Moonbeam’ and ‘Zagreb’, are hardy in USDA Zones 5 through 9. These varieties spread slowly via rhizomes, forming substantial, long-lasting clumps. Lanceleaf Tickseed (C. lanceolata) is another robust perennial, recognized by its lance-shaped leaves and bright golden-yellow flowers.
C. lanceolata is reliably perennial in Zones 4 through 9 and is often found in wildflower mixes. By contrast, the annual Plains Tickseed has a more upright, bushy habit and is often sold in mixed colors, indicating it will only last one season. Large-flowered Tickseed (Coreopsis grandiflora) is a common short-lived perennial, often requiring replacement every two to four years to maintain vigor.
Essential Care for Long-Term Growth
To ensure perennial Tickseed varieties return for many seasons, proper site selection and management are necessary. Perennial Coreopsis thrives in full sun, requiring at least six to eight hours of direct light daily for abundant flowering. The most important requirement for longevity is well-draining soil, as heavy, wet soil during winter dormancy can cause root rot.
These plants naturally prefer lean, sandy, or rocky soil. Excessive fertilization is counterproductive, often leading to weak, floppy growth and reduced bloom production. A light layer of compost in the spring is typically all the feeding required.
While deadheading individual blooms is time-consuming, shearing the entire plant back by about one-third of its height after the first wave of flowers fades will encourage a second flush of blooms. Perennial varieties, particularly clumping types like C. grandiflora, benefit from periodic division every two to four years. This practice involves digging up the clump and separating the healthy outer sections from the woody center, which revitalizes the plant’s vigor.
In cold regions, perennial varieties are herbaceous, meaning their top growth naturally dies back with the first hard frost. Gardeners should leave the dead foliage standing through winter, as it provides natural insulation for the crown and roots. This material can be cut back to the ground in late winter or early spring just before new growth emerges.