If you're looking for low maintenance, drought-tolerant, long-blooming and cheerful plants for a flower border or a filler, coreopsis are a perfect choice. With more than 80 species of coreopsis, plus many selections and hybrids, there's a perfect plant for your sunny garden. About half of the varieties are Native North American prairie and woodland plants, while the others are native to Central and South America. 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 their colorful blooms. 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, once danger of frost has passed. Annual varieties will start blooming in early summer and repeat bloom periodically through fall, while perennial varieties will begin blooming the second year after planting..
|Common Name||Tickseed, Pot of Gold|
|Plant Type||Perennial flower|
|Mature Size||10 to 18 inches tall and 12 to 24 inches wide|
|Sun Exposure||Full sun, part shade|
|Soil Type||Well-draining, sandy soil|
|Soil pH||5.5 to 6.5|
|Flower Color||Yellow, orange, pink, red|
|Native Area||Prairie and woodlands of North America|
How to Grow Coreopsis
You can find a handful of coreopsis varieties for sale as plants. For the best selection, order from catalogs or start your plants from seed. Hardiness will vary with species and cultivar, and not all coreopsis varieties are perennial plants—you'll find both annuals and perennials. Many of the newer varieties are still being tested for hardiness, and their ratings may change.
Mature size varies with species, age, and growing conditions, with coreopsis plants reaching from six inches to four feet in height with a spread of about 12 to 24 inches. They tend to grow in clumps, but many varieties will self-sow throughout your garden. There are also a few that will spread by runners. Some of the taller species may require staking to look attractive, especially if grown in partial shade.
Deadheading will keep the plants blooming throughout the summer and fall. Some of the smaller flowered varieties are difficult to deadhead, and you may prefer to shear the plants, once the first flush of flowers fade. They will fill in quickly.
Coreopsis will bloom best in full sun, but it can also be successfully grown in partial sun. The plants may get a bit lankier in partial shade. In areas with intense heat, coreopsis may even prefer some afternoon shade.
Most coreopsis varieties are very easy to grow and are not particular about soil quality or soil pH. They like well-draining soils and some, such as the thread leaf coreopsis, will tolerate dry, rocky soils. Heavy, wet clay soils should be amended with compost to help drainage.
Coreopsis will need regular water when first planted until they are established. After the first year, they are drought tolerant, but they'll bloom most prolifically with regular watering. Water the plants deeply at least once a week to help new roots grow down deeply. Soil should be moist at about one 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.
Temperature and Humidity
Coreopsis plants prefer a warm climate. They dislike too much standing water, which can cause root rot. Occasional wet weather won't bother them, though.
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.
Although they are rugged plants, they don't tend to live more than three to five years. A decrease in flowering is a signal it is time to divide the plants or plant some new ones from seed. For perennial coreopsis, if they begin looking weak with fewer flowers after three years or so, divide them if needed in spring or early fall.
Dig up the plants.
Use a trowel to divide the plants into smaller sections.
Replant and keep them well-watered until they are established and growing, which can take several weeks.
Varieties of Coreopsis
- Coreopsis Grandiflora 'Early Sunrise': Large, semi-double bright yellow flowers starting in early summer
- Coreopsis Grandiflora 'Golden Showers': Profuse, cheery yellow blooms on long stems
- Coreopsis Verticillata 'Moonbeam': Buttery yellow flowers on a compact plant; extremely airy
- Coreopsis Verticillata 'Zagreb': Golden yellow flowers on compact plant; dependable
- Coreopsis Rosea 'Nana': Mauve-pink, dwarf variety; spreads nicely but not as drought tolerant
Growing Coreopsis From Seeds
Many, although not all, coreopsis varieties can be grown from seed, either started indoors six to eight weeks before your last expected frost or direct seeded outdoors after last frost. Many will seed themselves; however, the hybrid varieties do not grow true to seed.
Common Pests and Diseases
For the most part, coreopsis plants grow problem free. In damp seasons they many fall prey to snails and slugs and fungal diseases can affect them. To avoid these problems as much as possible, give them plenty of air circulation and plant them in full sun.