Stemless carline thistle

Stemless carline thistle: how do you recognise it?

Habit

Flat rosette about 10 cm tall and 20–30 cm wide, with the almost stemless flower in the centre.

Leaves

Deeply divided with spiny edges, dark green to grey-green, in a star-shaped rosette.

Flower

A flower head up to about 10 cm across, with a ring of glossy silvery white bracts around a brownish centre, from July to September.

Fruit

Small seeds with a tuft of feathery hairs, spread by the wind.

Roots

A long taproot that reaches deep into the soil; that is why it dislikes being moved.

Flowering: July–September · Plants: March–April and September

Why grow it?

• A spectacular silvery white flower in July–September, just above a spiny rosette.
• Bees, bumblebees and butterflies visit its nectar-rich centre.
• Fully hardy and drought tolerant: perfect for a poor, sunny rock garden.
• The dried flowers stay beautiful for months in a dried arrangement or as decoration.
• A natural weather forecaster: the flower closes in damp weather.

Stemless carline thistle: where does it grow best?

• Full sun.
• Poor sandy or loamy soil, neutral to chalky, with plenty of gravel or grit.
• Dry: it cannot stand wet feet, especially in winter.
• Ideal in a rock garden, gravel garden, trough or on a sunny bank, where taller plants cannot smother it.
• Allow 30 cm per plant; it looks best in a small group of three.

Light

Sun

Soil type

Sand or loam

Acidity

Neutral or chalky

Moisture

Dry

Size

0.1 m tall, 0.3 m wide

Hardiness

Hardy (to -35 °C)

Goes well with

• Houseleek: Neat rosettes in the same dry, sunny spot.
• Thyme: A low, fragrant carpet around the silver flower.
• Stonecrop: Low, drought-tolerant ground covers for the rock garden.
• Pasque flower: Spring flowers and silvery seed heads on the same chalky soil.
• Blue fescue: Blue-grey tufts that make the silver stand out.

Stemless carline thistle: when and how to plant it?

Plant in March–April and September.

1. Plant in March–April or in September, using small, young pot-grown plants: the taproot dislikes disturbance.
2. On heavier soil, mix plenty of coarse sand or gravel into the planting spot, or plant on a raised bed.
3. Dig a deep hole and ease the root ball out of the pot without damaging the taproot.
4. Set the plant at the same depth as it was in the pot: the rosette should sit on the soil.
5. Water once, then only during long dry spells in the first few weeks.
6. Spread a layer of gravel around the rosette; it keeps the leaves dry.

Care

Watering

Hardly ever needed once established.

Feeding

Never: it belongs on poor soil.

Open space

Keep neighbouring plants and weeds away, so the rosette gets light and air.

Drying flowers

Cut flowers that have just fully opened and dry them flat in a dry, airy place.

Tidying

Carefully remove dead or rotting leaves, wearing gloves.

Tip: Plant it on an open, gravelly spot in full sun, away from taller plants, and never give it fertiliser or extra water: the poorer and drier the soil, the finer the rosette.

Stemless carline thistle: when to prune it?

When: Carline thistle is not pruned. In autumn you can leave the faded flowers in place or cut them for drying.

How:

• Leave the dried flowers standing in autumn: they decorate the rock garden well into winter.
• If you want them indoors, cut them with a short piece of stem and let them dry.
• Only remove dead leaves if they are rotting, and wear gloves when you do.

Pruning calendar and basic rules

Propagation

Seed

In autumn or March, sow ripe seed in small, deep pots of sandy compost and place them outdoors or in a cold frame. Plant out as young as possible with the root ball intact, because of the taproot.

Self-seeding

On an open, gravelly spot it sometimes self-seeds. Move the seedlings while they are very young, or leave them where they come up.

Stemless carline thistle: how does it get through the winter?

Hardy to −35 °C.

• Fully hardy, to about −35 °C: frost is no problem.
• Winter wet is its worst enemy: make sure drainage is excellent and add a layer of gravel.
• Do not put leaves or mulch on the rosette.
• In a trough or pot: stand it under a roof overhang, so the compost stays dry.

Diseases and pests

• Rot: The rosette turns brown and soft in a wet winter or on heavy soil. Plant in gravel and never overwater.
• Being crowded out: Taller neighbours take away light and air, and the plant fades. Keep the space around the rosette clear.
• Slugs: They eat the leaves of young plants. Pick them off in the evening.
• Disappearing after a few years: Plants are sometimes fairly short-lived. Collect seed regularly so you always have young plants in reserve.

Through the year

• March: Sow in deep pots. Planting. Remove rotting leaves.
• April: Planting. Top up the gravel around the rosette.
• May: Weed around the rosette.
• June: The rosette grows; keep the space around it clear.
• July: Flowering begins.
• August: In flower, busy with bees. Cut flowers for drying.
• September: Last flowers. Planting. Collect seed.
• October: Leave the dried flowers standing as decoration.
• December: Rest. Make sure the rosette stays dry.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Butterflies

Nectar for butterflies.

Did you know?

• Because the bracts close in damp weather and open in dry weather, people in the Alps used to hang the flower on their doors as a weather forecaster.
• The glossy ‘petals’ are really bracts; the true tiny flowers are packed together in the centre.
• According to legend, the genus name Carlina is derived from Charlemagne.