How to Plant and Grow Coreopsis

Coreopsis is a highly adaptable group of plants, easy to use in nearly all garden settings. It's available in an array of colors and patterns, especially the tender perennial and annual coreopsis. With bright little blossoms, coreopsis makes great companion plants for ornamental grasses and other tough annuals and perennials.

Coreopsis typically begins blooming in early summer, and the blossoms can last a while. 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.

Coreopsis height varies by type, with dwarf varieties remaining under two feet tall. Some varieties, like verticillata, extend creeping rhizomes, creating dense stands of the plant.

Where to Plant Coreopsis

Coreopsis is a low-maintenance flowering plant suitable for beds, borders and containers. Some coreopsis plants are perennials in USDA zones 3–9, while some are annuals. Plant coreopsis in well-draining soil that receives six to eight hours of full sun daily for the best bloom production. The plant tolerates light shade, but the bloom is not as robust.

How and When to Plant Coreopsis

After the last frost in spring, sow coreopsis seeds outdoors in prepared soil. Don't cover the seeds; they need light to germinate. Keep the soil moist until they germinate. The soil doesn't need to be amended as long as it drains well. As they grow, thin the plants to 12 to 18 inches apart.

Gardeners can get a head start on the season by sowing coreopsis seeds indoors in a seed-starting mix eight weeks before the last frost (not covering the seeds). Keep them warm and moist until they germinate. Transplant annual coreopsis plants outdoors in spring. Perennial coreopsis can be transplanted outside anytime between spring and early fall.

Coreopsis is often available as a nursery-grown plant. Plant it in spring or early summer in a prepared bed. Dig a hole the same depth as the nursery container and only a little wider. Set the plant in the hole at the same level it was in the container. Backfill with soil and tamp it down. Water regularly until the plant is established.

Coreopsis Care Tips

Coreopsis can survive in less-than-ideal conditions. They're known to thrive along roadsides and in ditches. Comparatively, gardens provide practically ideal conditions, even when the soil is sub-par.

Light

These drought-tolerant plants require lots of sun. In shade, coreopsis won't bloom as well, becomes leggy, and is more prone to foliar diseases.

Soil and Water

After they are established in the garden, coreopsis plants prefer to be left a little on the dry side. The soil doesn't need to be enriched; coreopsis grows well in most soil conditions as long as it drains well.

Temperature and Humidity

Coreopsis prefers a daytime temperature of 70°F to 80°F and a nighttime temperature above 50°F. It tolerates summer humidity and drought conditions.

Fertilizer

Do not fertilize coreopsis plants at any stage of their growth. Applying fertilizer reduces flower production and leads to spindly plants.

Pruning

Perennial coreopsis is a long-blooming plant that can be coached into reblooming by meticulous deadheading. Cut the flower stalk with the dead bloom all the way back to the ground. Annual coreopsis doesn't require deadheading.

Prune coreopsis for cosmetic purposes or to remove dead or damaged stems at any time during the season.

After frost in the fall, cut perennial coreopsis plants down to about 6 inches from the ground.

Potting and Repotting Coreopsis

Coreopsis is an excellent container plant and a welcome addition to a sunny patio or garden path. A container with drainage holes and well-draining soil is all that is needed. Choose a container several inches wider than the nursery plant container for a single plant, or fill a half whiskey barrel with three or more plants.

You don't need to worry about repotting annual coreopsis because it only lives one year. As for perennial coreopsis, cut the foliage back to 6 inches each winter; repotting may be unnecessary.

Pests and Problems

Although relatively pest-free, coreopsis is known to attract aphids and coreopsis beetles. Treat aphids and beetle larvae with commercial insecticidal soap. Deal with adult beetles by flicking them off the plant into a jar of soapy water.

When coreopsis is planted in shade, it is vulnerable to foliar diseases such as downy mildew and powdery mildew.)

How to Propagate Coreopsis

Coreopsis can be propagated by seed, cuttings, or division.

Seeds: Seed heads form at the site of a dead or dying flower. If the seed head is already dry, pluck it and crush it between your fingers to harvest the seed, which you can plant the following spring. If the seed head has not dried, cut about 6 inches of the stem it is on and hang it upside down in a warm, dry place until it dries. Then crush it to harvest the seed.

Division: Use a spade to lift an entire perennial coreopsis plant and root ball from the ground. Choose a mature plant that is at least two years old. With a garden trowel, carefully divide the plant into several sections, each with its own roots, being careful not to damage the roots in the process. Plant each division in the garden immediately and water well.

Cuttings: Cut a 4-to-6-inch piece of stem beneath a node at a 45° angle. Remove all the leaves except for those at the top of the cutting. Dip each cutting into rooting hormone and insert it into a pot of vermiculite or perlite until only the top leaves are showing. Moisten the planting medium, and place the pot in a bright, warm place. Check for roots in two or three weeks by gently tugging on a leaf. After they develop a healthy root system, they can be planted in the garden.

Types of Coreopsis

Combining both annual and tender perennial coreopsis with hardy varieties widens the array of available colors and yields some beautiful annuals that bloom nonstop from summer through fall—no deadheading needed. These make a great alternative for late-summer and fall plantings.

'Creme Brulee' Coreopsis

'Creme Brulee' is a more vigorous version of 'Moonbeam' coreopsis at 18 inches tall and 24 inches wide. It is hardy in Zones 5–9 and produces large flowers all along its stem, giving the plant a fuller-than-average appearance.

'Early Sunrise' Coreopsis

'Early Sunrise'—or Coreopsis grandiflora—is a dwarf form that grows only 15 inches tall and blooms the first year from seed. It tends to be short-lived and prefers Zones 4–9.

Lanceleaf Coreopsis

Coreopsis lanceolata is hardy in Zones 3–8 and bears bright yellow daisies in May and June. It grows to about 2 feet tall.

'Limerock Dream' Coreopsis

'Limerock Dream' is usually grown as an annual but is hardy in Zones 6–9. It produces two-tone pink flowers with feathery leaves. This variety requires good soil drainage over winter.

'Limerock Ruby' Coreopsis

'Limerock Ruby' stuns with deep pink daisies on feathery foliage that resembles the greenery of the threadleaf coreopsis. It's generally grown as an annual but is hardy in Zones 7–9.

'Moonbeam' Threadleaf Coreopsis

'Moonbeam'—or Coreopsis verticillata—is a stalwart in the sunny perennial border. It is self-cleaning and has a long season of pale yellow daisies. Plant this beauty in Zones 4–9.

Pink Coreopsis

Coreopsis rosea is one of the oddballs of the family. It has pink flowers instead of the usual yellow and prefers more moisture than other varieties. Divide the spreading clumps yearly to keep them growing vigorously. It's suited for Zones 3–8.

'Zagreb' Threadleaf Coreopsis

'Zagreb'—or Coreopsis verticillata—grows to 18 inches tall and bears brilliant gold daisies on ferny medium green foliage. This is a reliable pick for Zones 4–9.

Coreopsis Companion Plants

Salvia

Hundreds of different salvias, commonly called sage (including the herb used in cooking), and new selections for ornamental gardens appear annually. What most have in common are beautiful, tall flower spikes and attractive, often gray-green leaves. They're valued for their long bloom season, which extends right up until frost. Although not all are hardy in cold climates, salvias are easy to grow as annuals; they like full sun or very light shade with well-drained, average soil. The loose spires of tubular flowers in bright blues, violets, yellow, pinks, and red mix well with other perennials in beds and borders.

Veronica

Easy and undemanding, veronicas catch the eye in sunny gardens over many months. Some have mats with loose clusters of saucer-shaped flowers; others group star or tubular flowers tightly on straight-up spikes. A few veronicas bring elusive blue to the garden, but more often, the flowers are purplish or violet-blue, rosy pink, or white. Provide full sun and average, well-drained soil, and extend bloom time with regular deadheading.

Yarrow

Yarrow lends a wildflower look to any garden. Perhaps predictably, it's easy to care for. In some gardens, it will thrive with almost no attention, making it a good candidate for naturalistic plantings in open areas and along the edges of wooded or other wild places. Its colorful, flat-top blooms rise above clusters of ferny foliage. The tough plants resist drought, are rarely eaten by deer and rabbits, and spread moderately quickly, making yarrow a good choice for massing in borders or as a groundcover. If deadheaded after the first flush of blooms fade, yarrow will rebloom. If left to dry on the plant, flower clusters of some types provide winter interest.