Purple coneflower

How to recognise it

Habit

Upright, clump-forming perennial, 80–120 cm tall and 40–50 cm across, with sturdy stems that branch little.

Leaf

Oval to lance-shaped, 10–20 cm, coarsely toothed and rough to the touch; the basal leaves have long stalks, the stem leaves are smaller.

Flower

Flower heads 8–12 cm across with pink to purple ray petals that droop slightly, around a domed, orange-brown centre of disc florets with stiff, prickly scales.

Fruit/Seed

Small, four-angled achenes that ripen between the spines of the dry brown cone.

Roots

A sturdy rootstock with fibrous roots; the plant spreads slowly and does not run.

Look-alikes

Rudbeckia has yellow ray petals and a black, less prickly centre. Pale purple coneflower (Echinacea pallida) has narrower, pale pink, strongly drooping petals.

Flowering: July–September · Pruning: March

Why grow it?

• Long flowering season from July into September, well into late summer.
• A real bee and butterfly plant: honeybees, bumblebees, solitary bees and butterflies such as the peacock and the small tortoiseshell come for nectar and pollen.
• The sturdy seed heads stand all winter and feed goldfinches and other seed-eating birds.
• Once established it copes well with drought and heat: a plant for a climate-proof garden.
• A lovely cut flower; the cone-shaped centre still looks good in a dried arrangement after the petals have gone.
• Fits into a prairie border, a gravel garden or a flowery border among ornamental grasses.

Purple coneflower: where does it grow best?

• In the wild: open prairies, dry grasslands and light woodland in eastern and central North America.
• Full sun is ideal; in light shade it flowers less and flops more easily.
• Free-draining, ordinary garden soil: sand or loam, preferably not too rich. Heavy, waterlogged clay in winter is its worst enemy.
• Tolerates drought well once established; perfect in a prairie border or a gravel garden.
• Allow 40–50 cm per plant, in groups of 3–5 for the best effect.

Goes well with

• Black-eyed Susan: Yellow flowers next to the pink ones, in the same sun and flowering just as long.
• Argentinian vervain: Airy purple flowers above the border: together a butterfly magnet.
• Switchgrass: A light prairie grass that turns red in autumn and stands through the winter.
• Anise hyssop: Blue spikes with an aniseed scent and the same needs: sun and free-draining soil.
• Sedum: Flowers on into September–October and then still attracts bees and butterflies.

Purple coneflower: when and how to plant it?

1. Buy plants from a nursery or garden centre; never dig plants up from the wild.
2. Plant in April–May or in September, so the roots can grow before the summer heat or the winter.
3. Loosen the soil and on heavy clay mix in some coarse sand or gravel for good drainage.
4. Plant at the same depth as in the pot, no deeper: the crown must not end up below the surface.
5. Water regularly for the first few weeks until it is established, then only during prolonged drought.
6. You can also sow it: in March–April indoors, or in autumn in a pot outside, as the seed germinates better after a cold spell.

Care

Water

In the first year, water weekly in dry spells. After that it usually copes on its own; only water during long heatwaves.

Feeding

Not needed. In rich soil the stems become floppy and the plant is shorter-lived. A thin layer of compost in spring is enough on poor sandy soil.

Spent flowers

In July–August, cut off some of the faded heads to prolong flowering, but from September leave everything standing for the birds.

Slugs

Protect the young shoots in April–May: slugs can eat an entire plant. A ring of sharp sand or picking them off in the evening helps.

Rejuvenating

After 4–5 years the clump sometimes loses vigour. Rejuvenate it by dividing in spring, or let young seedlings grow on.

Tip: Let a few seed heads ripen in late summer and do not tidy them away in winter: you will get goldfinches in the garden, and now and then a seedling to replace the old plant.

Pruning and mowing

Pruning months: March.

When: Late February to late March, before the new shoots appear.

How:

• Leave the stems and seed heads standing all winter: goldfinches eat the seeds and insects overwinter in the stems.
• In March, cut them back to just above the ground, before the new rosette starts to grow.
• Want shorter, sturdier plants? At the end of May, cut half of the stems back by a third: they will flower a little later and lower.
• Put the cut stems on a brush pile or in a quiet corner, so the insects inside can still emerge.

Caution: Do not cut back in autumn: you would take away the winter food and shelter of birds and insects.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Sow indoors in March–April at 18–20 °C, or in autumn in a pot outside: after a cold spell the seed germinates better. Seedlings usually flower from the second year. Named varieties do not come true from seed.

Division

In April, lift an older clump and cut it with a spade into pieces, each with a few buds. It dislikes disturbance: only do this with older plants.

Root cuttings

In winter, lay 5 cm pieces of thick root in a pot of sandy compost; they sprout in spring.

Purple coneflower: how does it get through the winter?

Hardy to −30 °C.

• The leaves die back in autumn; the plant overwinters as buds on the rootstock just below the surface.
• The dark seed heads on their stiff stems stay standing and look beautiful with frost or snow on them.
• Fully hardy, to about −30 °C; heavy, wet soil in winter is more dangerous than frost.
• Goldfinches and other seed-eaters pick the seeds from the heads until deep into winter.

Diseases and pests

• Slugs: They eat the young shoots in spring. Pick them off early in the morning or in the evening, and give hedgehogs, toads and ground beetles a place in the garden.
• Winter rot: In wet, heavy soil the rootstock rots. Plant in free-draining soil, if need be slightly raised, and improve clay with gravel.
• Short life: Coloured and double varieties in particular often disappear after 2–3 years. Choose the species or robust varieties, and let a few seedlings grow.
• Green, deformed flowers: A sign of a phytoplasma, spread by leafhoppers. There is no cure: remove the plant, roots and all, and put it in the household waste.
• Powdery mildew: White powder on the leaves in dry late summers. Harmless to flowering; give the plants space and water at the base.

Through the year

• March: Cut old stems back to just above the ground. Sow indoors.
• April: Plant or divide. Protect young shoots from slugs.
• May: Optionally cut back half of the stems for a shorter plant.
• June: Buds appear. Water young plants in dry spells.
• July: Flowering begins. Watch the bees, bumblebees and butterflies.
• August: Full flower. Cut off some of the faded heads to prolong flowering.
• September: Last flowers. Leave the seed heads. Planting is still possible.
• October: Collect seed and sow it straight away in a pot outside.
• December: The seed heads stay standing for the goldfinches.

Did you know?

• The name Echinacea comes from the Greek echinos, hedgehog or sea urchin, after the prickly centre of the flower.
• Linnaeus described the plant in 1753 as Rudbeckia purpurea; only in 1794 did it get its own genus, Echinacea.
• Thanks to crosses with other coneflower species, there are now also white, yellow, orange and red varieties.