Coreopsis (Coreopsis grandiflora)

by Dr. William C. Welch, Extension Horticulturist, Texas AgriLife Extension Service
Texas A&M University, College Station, TX

Perennials are finding their way back into many gardens after many decades of absence. By definition, perennials are plants that return each year from a permanent crown or root system.

C. grandiflora is a native to Texas along with a number of other Coreopsis species. The species itself is a useful and colorful plant but is tall and falls over after spring rains or wind. New selections, such as ‘Baby Sun’ and ‘Sunray’ are valuable because they are compact and therefore, more useful in the landscape. Plants of these two varieties are usually 8 - 10" tall with bloom heads reaching to eighteen inches. ‘Sunray’ is a double flower more orange than yellow in color. ‘Baby Sun’ is single and a rich, golden yellow. ‘Zagreb’ and ‘Zamphir’ are also low-growing varieties - the latter has rolled petals which are unusual for flower arranging. Culture is undemanding with a sunny location being the primary requirement.

Coreopsis are very drought and heat tolerant. They flower from April through most of the summer. Like most spring and summer flowering perennials, they should be divided and reset in the fall. This should be done every one to two years. New plants can also be started from seed, which is available from many mail order seed sources. Started plants are being grown and made available by nurseries specializing in perennials and native Texas plants.

Although most people use the genus name coreopsis, Hortus Third lists the common name as tickseed, which describes the mature seed of the plant. Annual forms of Coreopsis bloom earlier and are more common than the perennial types. Coreopsis tinctoria is especially conspicuous in mid-spring with its fine textured foliage and dark red, or bi-colored red, brown and yellow disc flowers.

With increasing emphasis on utilizing our native Texas plants, Coreopsis seems a logical choice for homeowners. Groups of ‘Sunray’ or ‘Baby Sun’ spaced 12" apart are highly effective as a mass display in the landscape. Once established, they are exceptionally heat and drought tolerant and are among the easiest perennials to grow.