Caucasian scabious

Caucasian scabious: how do you recognise it?

Habit

Perennial clump 50–60 cm tall and 40–45 cm wide, with a rosette of leaves at the base and long, wiry flower stems.

Leaves

Grey-green and lance-shaped at the base; on the stems more deeply cut and narrower.

Flower

Large, flat, cushion-shaped flower heads (6–8 cm) with protruding stamens, from June to September.

Colour

Lavender blue to lilac; white and soft blue cultivars also exist.

Roots

A sturdy, deep taproot: it tolerates drought, but not soil that is too wet and heavy.

Flowering: June–September · Sowing: March · Plants: March–May · Pruning: March

Why grow it?

• Flowers from June to September, often until the first frost if you remove faded flowers.
• A lovely cut flower: the long, sturdy stems last well in a vase.
• Attracts bees and butterflies with plenty of nectar.
• Loves chalky, dry soil where many other plants struggle.
• Airy flowers on thin stems give any border a soft, natural look.

Caucasian scabious: where does it grow best?

• Full sun for the richest flowering; in partial shade it becomes floppy and flowers less.
• Free-draining, chalky to neutral soil: sand, loam or clay; in heavy clay mix grit or sand into the soil.
• Dry to normally moist: wet feet in winter are its worst enemy.
• Plant 40–45 cm apart.

Light

Sun

Soil type

Sand, loam or clay

Acidity

Neutral or chalky

Moisture

Dry or normal

Size

0.6 m tall, 0.45 m wide

Hardiness

Hardy (to -30 °C)

Goes well with

• Steppe sage: Violet spikes beside the lavender-blue flowers, in the same dry sun.
• Yarrow: Yellow or white flat heads as a contrast in the same dry border.
• Shrub rose: Soft pastel shades in a romantic border.
• Ornamental grasses: Fine stems that make the light flowers move gracefully.

Caucasian scabious: when and how to plant it?

Plant in March–May.

1. Plant from March to May, when the soil is neither frozen nor waterlogged.
2. Dig a hole twice as wide as the root ball and mix in grit or sand if the soil is heavy.
3. Set the plant at the same depth as in its pot, with the crown at ground level.
4. Keep 40–45 cm between plants and firm the soil.
5. Water straight away. Mulch with a thin layer of gravel and keep the crown clear.

Care

Water

In the first year, water weekly in dry weather. After that it copes with ordinary drought.

Feeding

Little needed: a bit of compost in spring is enough. Too much nitrogen gives floppy leaves and fewer flowers.

Deadheading

Remove faded flowers regularly, down to a side bud or to the base: this keeps it flowering much longer.

Lime

On acid soil, add a little lime in spring; it likes a neutral to chalky soil.

Dividing

Divide the clump every 3–4 years in spring to keep it vigorous.

Tip: Remove faded flowers regularly: it then flowers until September. In heavy clay mix grit into the soil, because wet feet in winter are its worst enemy.

Caucasian scabious: when to prune it?

Pruning months: March.

When: In March, when new shoots come from the base. During summer, remove faded flowers.

How:

• In March, cut last year’s dead flower stems down to the leaf rosettes.
• In summer, remove faded flower heads down to a healthy side bud or a rosette.
• Cut flowers for the vase just as they open, in the morning, with sharp scissors.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In March–April, lift the clump and split it into pieces with roots and shoots. Replant straight away and water.

Seed

Sow in March indoors on seed compost at 15–18 °C and cover the seeds lightly. Cultivars do not always come true from seed.

Basal cuttings

In spring, take 5–8 cm cuttings from new shoots at the base and root them in sandy compost.

Caucasian scabious: how does it get through the winter?

Hardy to −30 °C.

• Hardy to about −30 °C: frost is not a problem in Belgium.
• Wet, heavy soil in winter is more dangerous than cold: ensure drainage with sand or grit.
• In a pot: keep the pot sheltered from rain so the roots do not rot.

Diseases and pests

• Slugs: They strip young shoots in spring. Collect them in the evening or set up a barrier.
• Powdery mildew: White powder on the leaves in warm, humid summers. Give more space and cut away affected leaves.
• Root rot: In wet, heavy soil in winter the plant dies. Ensure drainage and free-draining soil.
• Floppy and falling over: In rich soil or partial shade. Plant it in more sun and do not feed.

Through the year

• March: Cut back to the leaf rosettes. Plant, divide or sow indoors.
• April: Plant or divide. Add compost.
• May: Plant. Watch for slugs.
• June: Flowering begins. Remove faded flowers.
• July: Full flower: cut flowers and remove faded ones.
• August: Flowering. Water in long dry spells.
• September: Last flowers: bees and butterflies visit.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Butterflies

Nectar for butterflies.

Did you know?

• The English nickname pincushion flower refers to the stamens that stick out of the cushion-shaped flower head like pins.
• It is often still sold as Scabiosa caucasica: the plant was later moved to the genus Lomelosia.
• The more you cut flowers or remove faded ones, the longer it keeps flowering.