Coreopsis : to sow, to plant, to grow

Description and botany

Coreopsis, also called “Tickseed” belongs to family Asteraceae like daisies and sunflowers. It is native to prairies and wooded areas of North America and Mexico, where it grows naturally.

The genus includes around a hundred species, mostly perennial herbaceous plants such as Coreopsis grandiflora, the most widespread, Coreopsis auriculata or auricled coreopsis, Coreopsis lanceolata, very floriferous, Coreopsis rosea, Coreopsis verticillata with feathery fine foliage, and Coreopsis tripteris, also called “Tall Coreopsis” which easily reaches 1.80 m in flower.

Many cultivars, notably with heads sometimes very double or with dwarf habit, have been developed. While most old varieties have bright yellow flowers, cultivars with pink, red or purple flowers have been introduced.

There is also an annual Coreopsis, Coreopsis tinctoria.

With rapid growth, Coreopsis forms from a rhizomatous rootstock a dense, bushy clump more or less compact of erect, ramified stems. Depending on variety the habit is erect, dwarf or cushion-forming as Coreopsis ranges from dwarf to tall varieties measuring 0.20 to 1.20 m in height. It spreads fairly quickly by its rhizomes and is long-lived.

Coreopsis tinctoria – botanical illustration

These slightly downy branched stems bear deciduous foliage, sometimes evergreen, linear, finely cut and divided. Opposite, lanceolate, simple and entire leaves measure 4 to 15 cm long. They are often dentate and range from medium to dark green.

Coreopsis auriculata is distinguished by leathery foliage cut into lobes reminiscent of ears. Coreopsis lanceolata is characterised by lanceolate leaves only on the lower part of the clump and those of C. tripteris give off a anise scent.

From this neat, elegant and airy vegetation emerge at start of summer slender flowering stems. The flowering, particularly long and generous, takes place from late June until October, uninterrupted. The fine, light foliage is covered with a multitude of globose buds borne at stem tips or arranged in whorls along the thin stems.

Resembling small sunflowers or daisies, the flowers open as solitary heads or grouped in graceful corymbs 2 to 8 cm in diameter. Flowers are single, semi-double or very double pompon forms.

They consist of a single or double collar of ligules neatly arranged, more or less tight and irregularly dentate. They are set radially around a centre of florets from sun-yellow to red-brown, sometimes highlighted by a cluster of black stamens.

Generally golden-yellow, these large starry flowers now appear in a range of vibrant colours from pink to deep red, through sulphur or butter yellow and from bronze to purple. Bright yellow flushed with mahogany or splashed with purple, pink washed with ruby red, peach tinged with red — while sometimes plain, they more often display bi- or tri-coloured shades arranged as halos or contrasting blocks at base or tips of ligules, making them shimmer.

Their colours change and develop over time, fading or reddening further as autumn approaches.

These nuanced stars make excellent cut flowers for creating beautiful country-style summer bouquets.

This tireless, nectariferous flowering attracts butterflies and pollinating insects. Flowers develop into fruits, flat, dry achenes resembling insects, hence the name which in Greek means “bug”.

Some coreopsis flowers: C. ‘Moonbeam’, C. ‘Limerock Passion’, C. ‘Cosmic Eye’, C. ‘Mercury Rising’, C. grandiflora ‘Sunray’

Depending on species, Coreopsis is grown as an annual because of low frost hardiness or as a fully hardy perennial (to at least -15°C), able to adapt to all regions of France.

Easy to grow, it prefers full sun and tolerates any good, well-drained garden soil. It thrives in containers or in ground, at edges of borders, flowerbeds, mixed borders, rockeries or well-exposed slopes.

Main species and varieties

Most popular

Our favourites

Coreopsis rosea American Dream

A beautiful bushy perennial with compact habit. Suitable for borders, rockeries and flowerbeds

• Flowering time July to November
• Height at maturity 30 cm

See the product sheet

Coreopsis tripteris

Largest coreopsis! Ideal for natural or wild areas.

• Flowering time September to November
• Height at maturity 1,80 m

See the product sheet

Coreopsis verticillata Route 66 - Tickseed

A fabulous American novelty with dark, contrasting colouring. Its clean silhouette is striking on banks or in containers.

• Flowering time July to October
• Height at maturity 60 cm

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Coreopsis Full Moon Madness

A new selection with a lovely creamy yellow offering abundant, long flowering. Very effective on borders of beds, flowerbeds, mixed borders, rockeries.

• Flowering time July to November
• Height at maturity 60 cm

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Coreopsis grandiflora Sonnenkind

One of the brightest! Its compact habit makes it ideal for the front of beds, borders and even containers.

• Flowering time August to October
• Height at maturity 40 cm

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Coreopsis grandiflora Sunray

Large double daisies, bright yellow, that keep reblooming all summer. With compact habit, perfect at front of beds, borders, slopes or in pots!

• Flowering time July to November
• Height at maturity 40 cm

See the product sheet

Coreopsis Desert Coral

A new, fairly hardy variety still uncommon, notable for its compact habit and long, almost entirely red flowering. Ideal on a meadow-like bank, in rockeries or in a pot on the terrace.

• Flowering time July to November
• Height at maturity 30 cm

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Coreopsis Incredible Dwarf Mix Seeds

A rich mix of dwarf and compact coreopsis with multicoloured, abundant flowering. Sow in flowering borders, in beds or in pots on the terrace.

• Flowering time July to November
• Height at maturity 50 cm

See the product sheet

Coreopsis lanceolata Goldfink - Lanceolate-leafed Coreopsis

A small compact coreopsis covered with bright yellow stars. Essential in a sunny bed or in a flowered border where it will be simply generous and sunny.

• Flowering time August to October
• Height at maturity 25 cm

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Coreopsis Early Sunrise Seeds - Tickseed

An exceptional coreopsis that flowers 3 weeks earlier than others! A truly perennial variety, easy to grow in beds or in pots.

• Flowering time July to November
• Height at maturity 50 cm

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Coreopsis Limerock Ruby

A lovely newcomer with intense ruby-red flowers and tireless flowering. Its clean silhouette suits well-exposed borders or containers.

• Flowering time July to October
• Height at maturity 40 cm

See the product sheet

 

When and how to sow coreopsis seeds?

Sowing of Coreopsis seeds is carried out in February–March in seed trays under cover for early flowering or directly in place in May when frosts are no longer a risk. Sowing will flower continuously from first year.

Under cover

• Sow Coreopsis seeds thinly by broadcast in a tray containing a mix of potting compost and sand
• Cover seeds lightly with potting compost
• Firm slightly with a board
• Water generously with a fine spray
• Keep soil moist until germination (20 to 30 days) and in light, out of direct sun, at 20–25°C
• Thin out to keep only strongest young plants
• As soon as seedlings reach 10 cm, transplant them into individual buckets
• Late May–early June, plant young plants in garden

Direct sowing in open ground

You can also sow Coreopsis seeds directly in garden, in well-worked soil, loosened with compost and river sand and warmed.

• Sow thinly
• Cover lightly with compost
• Firm slightly
• Water and keep soil moist until germination
• Keep only strongest seedlings spaced about 30–50 cm apart

More tips to ensure successful sowing? Consult our sheets “How to succeed in sowing perennial plants” and “Succeed in sowing annual seeds

Planting

Where to plant Coreopsis?

Hardy, undemanding, with impressive hardiness (-15°C in well-drained soil), perennial Coreopsis grows almost everywhere in France. Its hardiness can however be threatened in regions with very severe winters. Once well rooted, it only needs sun and light soil to thrive year after year, and can self-seed.

Coreopsis tinctoria and its hybrids are frost-tender to -10°C, so they can be grown as annuals in garden or in pots and may need replacing each spring depending on region.

All need full sun to flower well; they will tolerate partial shade in warmer regions and most are tolerant of heat and drought.

As for soil, it is an all-rounder that copes with difficult conditions. Undemanding, it is content with good light, well-drained garden soil that stays cool in summer, where it will be more floriferous. It prefers light, porous, even calcareous soil, slightly sandy or poor. Very accommodating, it will do just as well in rich soil!

In poorly drained soil, it will be vulnerable to winter flooding that can be fatal, because it hates heavy soils.

With its often compact habit and versatile height, often limited to 40–60 cm, this daisy with warm colours fits well into unfussy gardens to compose simple, slightly wild-looking scenes. Plant this multi-purpose plant in beds, borders and flower beds, or in pots on the terrace.

Smaller Coreopsis also make excellent bright groundcover for difficult slopes, in a scree garden or rockery.

When to plant Coreopsis?

Planting of our perennial Coreopsis in buckets is done in spring from March to April or in autumn, south of the Loire from September to November, avoiding periods of frost or drought.

How to plant Coreopsis?

To develop well, Coreopsis needs well-drained, lightened soil: lighten heavy soils with river sand and compost.

Plan on 4 to 8 buckets per m² depending on variety, spaced 30 to 50 cm all round.

In open ground

• Work soil well and clear roots of weeds and stones
• Dig a hole 2 to 3 times the volume of the bucket
• Make a bed of gravel at bottom of planting hole
• Place rootball in centre of hole, collar level with soil
• Backfill with mixture of garden soil, compost and sand
• Firm gently
• Water regularly until established

In pots

Coreopsis is equally remarkable in containers.

• In a sufficiently large container, plant in a well-draining mix of planting compost, sand or gravel and compost
• Water generously once or twice a week

Coreopsis verticillata ‘Moonbeam’

Maintenance, pruning and care

Very easy to grow, Coreopsis is undemanding.

Hardy, once well established, it will require little water, tolerating short dry spells well: water once a week during prolonged summer drought.

Mulch during summer to keep soil cool.

Remove spent flowers throughout summer to encourage flowering until autumn and prevent seed formation that exhausts the plant.

Stems of taller varieties may need staking, especially in exposed, windy positions.

Cut back clump to ground level after flowering. At end of winter, remove dead, dry foliage.

Divide clumps every 2–3 years in spring to rejuvenate plants and keep them floriferous, as they tire quickly — it’s one of Coreopsis’s traits resulting from its great generosity!

In spring, repot or top-dress container-grown Coreopsis with a little compost.

Potential diseases and pests

Vigorous, Coreopsis has few enemies.

In spring, its young shoots are endangered by slugs and snails: discover our 7 ways to fight slugs effectively and naturally and how to make a slug trap.

Emergence of foliage of Coreopsis verticillata in spring: watch for slugs!

Sometimes small frothy spit-like patches appear on leaves caused by the spittlebug but harmless to the plant: spray with fern manure.

Propagation

If Coreopsis reseed fairly easily in the garden or can be propagated by sowing under cover in February–March, perennial species are easily maintained by dividing clumps in spring, in March, which also helps rejuvenate stumps that tend to become less floriferous over time.

• Using a digging fork, gently lift the stump
• With a spade, divide it into two or three divisions
• Replant immediately in the garden in well-drained soil

Companion planting with coreopsis

Richness of tones and abundance of its flowers make Coreopsis an indispensable plant in summer gardens, creating lovely splashes of colour in the foreground or middle distance of beds, rockeries or mixed borders with a country feel.

Whether annual or perennial, dwarf or tall, Coreopsis is indispensable in a naturalistic garden or unpretentious country garden. It brings vivacity, sparkle and sunny charm to all summer scenes. With its warm colours, it brightens every part of the garden and pairs with many annuals or summer-flowering perennials that, like it, enjoy full sun.

An example of a natural, flower-filled planting for the whole summer: Verbena bonariensis, Gaura lindheimeri, Carex buchananii, Coreopsis ‘Ruby Red’ (photo Leonora Enking – Flickr)

It benefits from being paired with warm colours in explosive yellow harmonies or in a deliberately brash contrast with the magenta of crocosmias, achilleas, valerians and shrubby salvias and vivid yellow/blue of centaureas or Eryngium, hardy geraniums, Echinops, Erigeron or nepetas.

Its star-shaped flowers will find an echo among other annual or perennial daisies such as Rudbeckias, Echinacea, bidens, rockroses, gaillardias. Asters and chrysanthemums will accompany Coreopsis flowering until late autumn.

Coreopsis’s often compact habit and strongly defined flower form introduce bold accents in a composition. Larger, slightly wild plants such as grasses, Stipa, Carex, Eragrostis or Pennisetum are perfect to bring softness, movement and lightness to a naturalistic scene, as are the flatter, globular inflorescences of achilleas or oriental poppies.

An example of a planting at the edge of a bed or in a container: Coreopsis ‘Twinklebells Pink’ (but also ‘American Dream’ or ‘Limerock Passion’ to stay within pink tones), Prunella, Ceratostigma plumbaginoides and variegated Ajuga reptans such as ‘Golden Glow’ or ‘Multicolor’

Rely on the warmth and brightness of Coreopsis colours to give character to a joyful summer border by surrounding it with Cosmos, dwarf Dahlias, Phlox, wallflowers, love-in-a-mist (Nigella damascena), perennial flax and Gauras.

In a beautiful Catalan-inspired bed, opt for fiery combinations with cannas, heleniums, daylilies, tritomas that will accompany it until the first frosts.

On a difficult bank or a border, it is perfect with lavenders, thyme or santolinas.

In a wildflower meadow, taller Coreopsis will be paired with Leucanthemum, scabious, Anthemis.

In a pot, plant dianthus and Osteospermum alongside it.