Last Updated on September 16, 2022 by Plant Mom Care
Coreopsis is a species of more than 80 varieties of flowering plants and the genus belongs in the Asteraceae family. They are endemic to North America in 1991, Florida designated the entire species as the wildflower of the state.
These annual and perennial plants can grow 18–47 inches high and are low-maintenance and drought-tolerant. They grow in clumps and produce plenty of long-lasting daisy-like showy flowers that vary from orange, yellow, red, pink, and white but also come as a bicolor of yellow and red bicolor flowers throughout the summer.
The leaves vary with some having large green leaves while others have narrower leaves. The flat fruits are small and resemble round ticks, hence their common name, tickseed. The annual varieties start flowering in early summer through to autumn, while the perennial varieties will start flowering in their second year from planting.
These plants provide nectar for several insects, including butterflies, moths, bees, wasps, and hoverflies, and are a food source for the caterpillars of some species of butterflies and moths. These plants have daisy-like flowers and are popularly cultivated to attract butterflies in gardens.
Coreopsis Light Requirements
These plants grow and flower better under full sun, meaning that they need 6 or 8 hours of bright sun every day. They can also tolerate partial shade, but the plants may become gangly and not flower as abundantly. However, some shade in the afternoon is appreciated in very hot summers.
Young plants need to be regularly watered once a week until they become established. They develop good drought tolerance after their first year, although they produce more flowers when watered regularly, so adjust your watering frequency to once in 10 days or so. Watering these plants is best done in the morning as the leaves can dry during the day. Avoid over-watering as this can lead to problems with root rot.
These plants can tolerate high humidity as long as there is good air circulation and proper drainage.
These plants prefer warm daytime temperatures of 70-80°F and 50-60°F at night. However, the level of cold tolerance varies in some species of these plants.
These plants prefer well-draining sandy or loamy soil with a neutral soil pH. However, most varieties are easy to cultivate as they are not very selective about soil quality or pH, as long as the soil drains well and doesn’t get water-logged. In truth, some of these plants growing wild alongside roads and other areas produce more flowers. Amend clayey soils with compost and perlite to help drainage.
These plants need repotting and division every 2 or 3 years in containers 8-10 inches deep and as wide. Use well-drained soil and ensure the container has lots of drainage holes to keep water flowing out of the bottom, as these plants don’t like soggy soil.
You will have to monitor moisture levels of the soil more frequently as plants grow in containers and the soil tends to dry out faster.
Although the perennial varieties are hardy plants, they don’t live more than three or five years. Divide and propagate the plants when flowering slows down. Do this in spring or early autumn.
First, carefully dig the plant up or ease it out of its container and split several sections from the root ball. Replant each section in suitable growing sites and water them regularly until they get established and start showing signs of growth – this might take several weeks.
Many varieties can be propagated from seed and often reseed themselves. Start planting the seeds indoors 6 or 8 weeks before spring or directly plant the seeds around 1/2-inch deep in your garden after the last frost and keep the soil lightly moistened. Germination should start in 2 or 3 weeks. Seedlings started indoors have to be slowly hardened by taking them outdoors every day for around a week. Then transplant them in the garden.
Fertilization isn’t needed for these plants unless your soil is very poor. Too much feeding can increase foliage growth and reduce flowering, add a little compost instead at the beginning of spring.
To keep these plants flowering continuously, deadhead or cut spent blooms also help prevent the flowers from producing seeds and spreading rapidly.
Taller varieties may have to be staked as they mature to prevent the stems from flopping over.
Don’t cut the stems down in autumn as this perennial is short-lived and cutting it down will have a negative impact and turn it into an annual plant.
Coreopsis Common Problems
Aster yellows resulting from Phytoplasma infecting the plant and are transmitted by leafhoppers. Flowers develop long green or stunted petals and plenty of flower heads. The infected plants usually become stunted and yellow. Use an appropriate insecticide to control and eliminate leafhoppers.
Bacterial leaf spot creates brown blotches and spots on leaves. Remove infected foliage and monitor your watering schedule, only watering the plants in the morning and avoiding getting the leaves wet, use a suitable bactericide to protect the plants.
Botrytis blight makes lower leaves die and become coated with white/gray fungal growth that turns into a mass of spores. Adjust your watering schedule to only water the plants in the morning and avoid wetting the leaves. Apply a suitable fungicide and remove affected foliage.
Crown rot will make the plants wilt, turn brown and die, with white fungal growth and small, round, brown structures appearing at the plant’s base. Remove infected plants and ensure mulch does not touch the stems.
Root rot is usually caused by water-logged soil. Plants will become yellow, wilt and die. Stop watering the plants for a few days and apply a suitable fungicide. Repot or transplant the plants using well-draining soil and, if you’re growing the plants in containers, make sure the containers have enough drainage capacity.
Aphids will suck the juice from the plant and weaken it, but they’re easy to eliminate by spraying them off. Use insecticidal soap and/or neem oil to prevent re-infestation.