Bieberstein's crocus

Bieberstein's crocus: how do you recognise it?

Habit

Small corm of 10–12 cm; the flowers appear in autumn without leaves.

Leaves

Narrow and grassy with a white central stripe; they only appear after flowering, in spring, and die back in May.

Flower

Slender goblet with six petals that opens wide in sunshine, in September–October.

Colour

Lilac-blue with dark veins; a bright orange, finely branched stigma at the centre.

Corm

Small, round corm with a fibrous tunic, which forms cormlets.

Flowering: September–October · Plants: July–September

Why grow it?

• Fresh spring-like colours in autumn, as the rest of the garden winds down.
• A late source of pollen and nectar for bumblebees and honeybees on sunny autumn days.
• Naturalises in grass and under trees and forms blue carpets after a few years.
• Quick results: corms planted in July–August flower the same autumn.
• Small and inexpensive, so easy to plant in large numbers.

Bieberstein's crocus: where does it grow best?

• Sun to partial shade: the flowers open best in sunshine.
• Well-drained soil: sand, loam or clay, neutral to chalky.
• Moist, without standing water in winter.
• Plant 5–10 cm apart, in large groups in grass, under trees or at the front of a border.

Light

Sun and partial shade

Soil type

Sand, loam or clay

Acidity

Neutral or chalky

Moisture

Normal

Size

0.12 m tall, 0.05 m wide

Hardiness

Hardy (to -25 °C)

Goes well with

• Ivy-leaved cyclamen: Small pink flowers and patterned leaves at the same time, under trees.
• Ice plant: Pink flower heads in autumn, at the front of a sunny border.
• Creeping thyme: A low mat the crocuses grow through, which supports the stems.
• Michaelmas daisy: Flowers in the same months and fills the border behind.

Bieberstein's crocus: when and how to plant it?

Plant in July–September.

1. Plant in July–August, at the latest early September: it will then flower the same autumn.
2. Loosen the soil; in grass, lift a piece of turf or use a narrow trowel.
3. Set the corms 8–10 cm deep, pointed end up.
4. Keep 5–10 cm between them and plant in groups of at least twenty for a good show.
5. Firm the soil and water if it is dry.
6. Mark the spot, as there is nothing to see from spring until late summer.

Care

Watering

Not needed, except in a very dry late summer just after planting.

Feeding

Not needed. In a border, at most a thin layer of compost in spring.

Mowing

Do not mow over the flowers in September–October, and in spring wait until the leaves have yellowed, at the end of May.

Foliage

Let the leaves die back naturally in spring: this is how the corm builds up strength.

Naturalising

Let the seed ripen if you want it to spread.

Tip: Plant the corms in July–August, ideally in a patch of grass you do not mow in spring until the end of May: it will then naturalise and flower more freely every year.

Bieberstein's crocus: when to prune it?

When: Bieberstein’s crocus is not pruned. After flowering, simply leave it alone.

How:

• Let the spent flowers wither; they disappear on their own.
• In spring, leave the leaves until they turn yellow.
• At most, clear the dead foliage in June.

Caution: Do not mow or cut the green leaves in spring, or it will flower less in autumn.

Pruning calendar and basic rules

Propagation

Cormlets

Lift a crowded clump in June–July, once the leaves have died back, separate the cormlets and replant them straight away.

Seed

It self-seeds in grass and borders. Seedlings flower after a few years.

Bieberstein's crocus: how does it get through the winter?

Hardy to −25 °C.

• Fully hardy, to about −25 °C: in Belgium it simply stays in the ground.
• No protection is needed; only good drainage matters.
• In a pot: stand the pot against a wall in winter and keep it on the dry side.

Diseases and pests

• Mice and squirrels: They dig up and eat the corms. Plant them under a piece of wire mesh or among ground cover.
• Slugs: They eat the delicate flowers in autumn. Pick them off in the evening.
• Flopping flowers: After rain or wind the slender stems lie flat. Plant them among low ground cover or in grass, which supports them.
• Corm rot: In wet, heavy soil the corms rot. Plant in a drier spot or work in coarse grit.

Through the year

• March: Leaves grow. Do not mow.
• May: Leaves turn yellow. Only mow the grass after that.
• June: Dormant. Lift and divide crowded clumps.
• July: Plant corms 8–10 cm deep.
• August: Plant corms.
• September: Plant the last corms. First flowers. Do not mow.
• October: In flower. Watch for slugs.
• November: End of flowering. Leave the spot undisturbed.

Edible and useful

Not edible. This autumn-flowering crocus is not the saffron crocus: its stigmas are not saffron, which comes only from Crocus sativus. The corms are poisonous to people and pets. Do not confuse autumn crocuses with the highly poisonous Colchicum either, which has six stamens instead of three. If any is swallowed, call a poison centre (in Belgium 070 245 245) or your doctor at once.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• A crocus has three stamens and meadow saffron six: an easy way to tell these two autumn flowers apart.
• It is related to the saffron crocus, which also flowers in autumn; saffron comes only from the stigmas of the latter.
• Speciosus is Latin for beautiful or showy.