If you’re looking for low maintenance, drought tolerant, long blooming and cheerful plants for a flower border or a filler, coreopses are a perfect choice. Native American prairie and woodland plants, their ruggedness and profuse blooms have made them popular with plant breeders. Their common name, “tickseed,” is supposedly for the seeds’ resemblance to ticks. Even so, birds (particularly Goldfinches) love to snack on the seeds during fall and winter. Bees and butterflies are drawn to them, too. Their daisy-like flowers range in colors from bright yellow and orange to pink and red. Coreopsis form upright clumps and have a moderate growth rate. Plant them any time from early spring to fall; most varieties will start blooming in early summer and repeat bloom periodically through fall. Less-hardy varieties tend to be longer blooming, especially when deadheaded regularly to encourage new blossoms. As their bloom season progresses, be sure to leave a few flowers on the plants so birds can dine on the tasty seeds.
With their bright and cheery little blossoms, coreopsis can be great companion plants to ornamental grasses and other tough annuals and perennials, especially in containers. These drought-tolerant plants prefer to be left a little on the dry side and in all the sun they can get. (In shade, it won’t bloom as well and becomes leggy and prone to foliar diseases like powdery mildew.) Some varieties, like verticillata, can spread by creeping rhizomes and will create dense stands of the plant. In some cases, they can be a little aggressive in a garden setting, but can easily be dug up and divided.
Coreopsis will bloom best in full sun, but it can also be successfully grown in partial shade. The plants may get a bit lankier in partial shade, but they will adapt. In areas with intense dry, heat, coreopsis may even prefer some afternoon shade. They like well-draining soils and some, such as the thread leaf coreopsis, will tolerate dry, rocky soils. Heavy, wet soils can be problematic for the clump-forming varieties in winter; amending with compost will help.
Coreopsis will need regular water when first planted until they are established. After that, they are drought tolerant. Water the plants deeply at least once a week to help new roots grow down deeply. Soil should be damp at about 1 inch below the soil surface (stick your finger in the soil to check.) Early morning watering is best, so the leaves have a chance to dry during the day. Fertilization of growing coreopsis is not necessary—in fact, too much fertilizer may inhibit flower production. If soils are already good, all you should need to do is add a little compost in the spring. A decrease in flowering is a signal it is time to divide the plants. Divide them when needed in spring or early fall.