Coreopsis, commonly known as Tickseed, is a popular choice for gardeners seeking a long-blooming, cheerful plant. This genus of flowering plants is native to North and South America and is celebrated for its bright, daisy-like appearance and ease of care. The genus contains over 100 species, alongside countless hybrids and cultivars, which has resulted in a wide range of looks, sizes, and colors. Coreopsis plants provide color in gardens from early summer until the first frost.
Defining the Coreopsis Flower
The Coreopsis bloom is instantly recognizable due to its classic, star-like structure, which places it within the large Asteraceae family. Its flowers are composite flower heads, made up of two distinct types of florets. The outermost petals, which resemble rays, are known as ray florets, while the tightly packed center is formed by disc florets. These blooms can range in size, from small, dime-sized flowers to larger heads measuring up to two and a half inches across, depending on the species.
The standard coloration for most native Coreopsis species is a rich gold or bright yellow. This classic sunny palette is common in species like Coreopsis grandiflora (Large-flowered Tickseed) and Coreopsis verticillata (Threadleaf Coreopsis). The ray florets are typically broad and flat, though some cultivars may display fluted or double-layered petals. The center disc florets are usually a matching shade of yellow, reinforcing the flower’s bright, golden appearance. The cheerful blooms are borne on slender, upright stems.
Foliage and Overall Growth Habit
The non-flower appearance of Coreopsis is highly variable and depends greatly on the species, especially concerning the leaves. The genus is broadly characterized by two main foliage types that offer very different textures in the garden. One type is the fine, nearly thread-like foliage, exemplified by Coreopsis verticillata. This Threadleaf Coreopsis has delicate, lacy leaves that create an airy, wispy mound, often referred to as whorled due to their arrangement along the stem.
The second major type features broader, more substantial leaves, which are often deeply lobed or lance-shaped. Coreopsis grandiflora and Coreopsis lanceolata display this leaf structure, creating a denser, more upright clump of bright green leaves. The overall height of Coreopsis plants varies widely, from compact, dwarf forms that reach only six inches tall to towering species like Coreopsis tripteris (Tall Coreopsis), which can grow up to four feet or more. Most garden varieties fall into a mounding habit between one and two feet in height, making them versatile for borders and containers.
Major Species and Color Variations
While the traditional Coreopsis look is dominated by shades of yellow, modern breeding has introduced a spectrum of colors and patterns that expand the genus’s visual appeal. This diversity is often found in hybrid cultivars, which deviate from the native yellow of species like C. grandiflora and C. verticillata. Breeders have successfully incorporated pigments to produce blooms in shades of pink, rose, red, and deep maroon.
Species such as Coreopsis rosea naturally produce pink blossoms, offering a softer appearance than the typical gold and yellow varieties. Beyond solid colors, many new cultivars feature bi-color patterns, such as yellow ray florets with a contrasting red or maroon center disc. Examples like ‘Li’L Bang™ Red Elf’ showcase intense ruby-red flowers with sunny gold edges. The appearance also changes with the plant’s life cycle; annual types bloom continuously until frost, while many perennial types require deadheading or shearing to encourage a fresh flush of blooms throughout the season.