Coreopsis are superb summer flowering perennials. They originated as native American prairie and woodland plants and have since been bred by hybridizers into a multitude of colors and sizes. They are one of the longest performing flowers for the summer garden. There are essentially two groups which are grown for mainstream garden use. Coreopsis verticillata (Threadleaf Tickseed) has thin delicate foliage which are topped with single daisies in a wide variety of colors. Coreopsis grandiflora has wider foliage and sports single and double flowers primary based around a golden color palette.
I use many of the thread leaf forms in the front of the border as they provide movement and a sense of delicacy in the garden. I tend to grow them in larger clumps of 3 or more. The finer foliage of the thread leaf forms looks attractive in spring, summer and fall. Thread leaf forms tend to look great when planted in conjunction with larger foliage plants. C. grandiflora looks well when planted with other summer blooming daisies such as coneflower and gaillardia.
Prefers full sun
Depending on the variety, they will start in early summer and repeat through fall. Deadheading helps continue the bloom.
Once established they are very drought tolerant. Regular deadheading and a quick shearing after the initial first blooms will help keep shape and promote further blooming.
PESTS AND PROBLEMS
Coreopsis can rot if planted in very heavy wet soil. Try to give them as much air circulation as possible.
Generally 10-18" tall x 12-24" wide depending on the variety
Birds are incredibly attracted to the seeds during the winder. They also make great cut flowers.