Cutleaf coneflower

Cutleaf coneflower: how do you recognise it?

Habit

Upright perennial, 1.5–2 m tall and about 1 m wide, forming a broad clump through underground rhizomes.

Foliage

Deeply cut, usually into three to seven lobes, hence the name; matt green, larger at the base of the stem than at the top.

Flower

Yellow flowers up to about 10 cm across, with drooping petals and a tall greenish-yellow cone, from July to October.

Double forms

‘Goldquelle’ has densely double, rounded flowers in lemon yellow and stays much lower, at about 1 m.

Roots

Creeping rhizomes: the clump widens every year and sends up suckers, sometimes some distance from the parent plant.

Flowering: July–October · Plants: March–May and September–October · Pruning: February–March

Why grow it?

• Flowers from July until October and brings yellow to the late summer and early autumn garden.
• Very tall: a natural focal point at the back of the border and a backdrop for lower perennials.
• The open flowers are busily visited by bees and butterflies.
• A good cut flower for large vases and informal bouquets.
• Thrives in moist to wet soil, where many other coneflowers struggle.
• Little maintenance once established.

Cutleaf coneflower: where does it grow best?

• Sun or partial shade; it flowers best in full sun.
• Tolerates heavy, moisture-retentive soil: loam, clay and even peaty soil, from acid to chalky.
• Likes a moist to wet spot; in prolonged drought the leaves droop.
• Site it in shelter or at the back of the border: the 2 m stems blow over easily in strong wind.
• Allow about 1 m of space per plant and remember that it spreads.

Light

Sun and partial shade

Soil type

Loam, clay or peat

Acidity

Not fussy

Moisture

Normal or wet

Size

2 m tall, 1 m wide

Hardiness

Hardy (to -35 °C)

Goes well with

• Helenium: Warm orange and red shades that flower at the same time and enjoy the same sun and moist soil.
• Michaelmas daisy: Purple and blue flowers in autumn, a lovely contrast with the yellow.
• Hemp agrimony: Just as tall and fond of damp soil; the pink flower heads attract plenty of butterflies.
• Ornamental grasses: Plumes of a miscanthus, for example, bring calm and movement between the bold flowers.
• Phlox: Tall phlox flowers in the same period and scents the late summer.

Cutleaf coneflower: when and how to plant it?

Plant in March–May and September–October.

1. Plant in March–May or in September–October, when the soil is neither frozen nor waterlogged.
2. Dig a hole twice as wide as the root ball and mix in a few spadefuls of compost.
3. Set the plant at the same depth as in its pot, with the crown at soil level, and firm the soil well.
4. Leave 80–100 cm between plants, as the clump becomes broad.
5. Water in generously straight away and spread a layer of leaf mould mulch around the base.

Care

Water

In the first year, water weekly in dry weather. Later only during long dry spells, in the morning and at the base.

Feeding

A spadeful of compost in spring. Too much fertiliser gives long, floppy stems that fall over.

Mulching

A layer of leaf mould in spring keeps the soil moist and suppresses weeds.

Support

In a windy spot, support the stems in May with a ring or twiggy branches.

Controlling spread

Each spring, slice off the suckers all around with a spade so the clump does not get too wide.

Spent flowers

Remove faded flowers to limit self-seeding; leave a few if you like the seedheads.

Tip: Plant it at the back of the border in moist soil and slice off the suckers all around each spring: that keeps the clump neat and stops it escaping. If you want a lower plant, choose the double ‘Goldquelle’.

Cutleaf coneflower: when to prune it?

Pruning months: February–March.

When: In February–March, before the new shoots appear. In summer you only remove faded flowers.

How:

• Cut last year’s dead stems down to just above the ground.
• Cut faded flowers back to a side shoot: this prolongs flowering.
• If you do not want seedlings, cut the seedheads off in autumn rather than in February.

Caution: Do not dump severed rhizomes or prunings on a verge or in woodland: pieces of rhizome can root there again.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In March–April or September–October, lift the clump and divide it with a spade into pieces with roots and shoots. Replant at once and water.

Seed

Sow in a tray in spring and barely cover the seed. It also self-seeds.

Cutleaf coneflower: how does it get through the winter?

Hardy to −35 °C.

• Fully hardy, down to about −35 °C: no protection is needed in Belgian winters.
• Leave stems and seedheads standing until late winter: they decorate the garden and shelter insects.
• A wet winter is no problem: the plant is used to moist soil.

Diseases and pests

• Spreading: It spreads every year by rhizomes and escapes along rivers. Slice off the suckers and do not plant it near nature reserves or the water’s edge.
• Flopping stems: Tall stems bend in wind and rain. A sheltered spot, less fertiliser and support in May help.
• Powdery mildew: White powder on the leaves in dry, stuffy summers. Give it space, water at the base and cut off affected leaves.
• Slugs: Young shoots are nibbled in spring. Pick slugs off in the evening or lay a barrier of coarse sand.

Through the year

• February: Cut dead stems down to just above the ground.
• March: Plant or divide. Apply compost. Slice off suckers.
• April: Plant. Mulch. Watch for slugs.
• May: Plant. Support tall stems.
• June: Water in dry weather. Keep an eye on suckers.
• July: Flowering starts. Cut flowers for the vase.
• August: Full flower. Remove faded flowers.
• September: Flowering. Plant or divide.
• October: Last flowers. Plant.
• November: Rest. Seedheads can stay standing.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Butterflies

Nectar for butterflies.

Did you know?

• Linnaeus named the genus Rudbeckia after Olof Rudbeck the Elder and Olof Rudbeck the Younger, father and son, both professors at Uppsala.
• The species name laciniata comes from the Latin laciniatus, ‘cut into strips’, after the deeply cut leaves.
• A double form of this species, ‘Golden Glow’, was for a long time a much-loved plant in older gardens, especially in North America.