Siberian bugloss

Siberian bugloss: how do you recognise it?

Habit

Broad, low clumps 40–45 cm tall and up to 60 cm wide.

Leaves

Heart-shaped, 10–20 cm, slightly rough and hairy; green, or silver-marked or cream-edged in cultivars. The leaves only reach full size after flowering.

Flowers

Loose, branching sprays of small, star-shaped flowers about half a centimetre across, in April–May.

Colour

Sky blue with a small, pale eye.

Roots

A short rhizome with thick, fleshy roots.

Flowering: April–May · Plants: March–April and September–October · Pruning: March and June

Why grow it?

• Sky-blue flowers in April–May, just when the spring bulbs are in bloom.
• Large, heart-shaped leaves that fill the shady border all summer; the silver-leaved cultivars light up dark corners.
• An early source of nectar for bees and bumblebees.
• A dense ground cover that gives weeds little chance.
• Little work: the clumps get fuller and finer every year.

Siberian bugloss: where does it grow best?

• Partial shade or shade; in sun the leaves scorch, especially in silver-leaved cultivars.
• Humus-rich loam or clay, acid, neutral or chalky.
• Soil that never dries out: moist is fine, dry is not.
• Plant 4–5 plants per m², 40–45 cm apart.

Light

Partial shade and shade

Soil type

Loam or clay

Acidity

Not fussy

Moisture

Normal or wet

Size

0.45 m tall, 0.6 m wide

Hardiness

Hardy (to -35 °C)

Goes well with

• Ferns: Fine, airy fronds beside the large, heart-shaped leaves.
• Hosta: Shares the summer show in the same moist shade.
• Barrenwort: Another tough ground cover for shade, with finer leaves.
• Daffodil: White or yellow flowers alongside the blue clouds in April.
• Foamflower: White spires and a low, green mat in the same shade.

Siberian bugloss: when and how to plant it?

Plant in March–April and September–October.

1. Plant in March–April or in September–October, when the soil is neither frozen nor too wet.
2. Dig a hole twice as wide as the pot and work in plenty of leaf mould or compost.
3. Set the plant at the same depth as in the pot and firm the soil well.
4. Space 4–5 plants per m², 40–45 cm apart.
5. Water in generously straight away, even if it is raining.
6. Mulch with leaf mould to keep the soil cool and moist.

Care

Watering

Keep the soil moist, especially in summer and in the first year. Drooping leaves mean thirst.

Feeding

Compost or leaf mould in spring; nothing more is needed.

Mulching

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

Spent flowers

Cut off the flower stems after flowering so the foliage can shine.

Green shoots

In variegated cultivars, remove shoots with plain green leaves, or they will take over.

Tip: Give the silver-leaved cultivars a spot with morning sun at most and keep the soil moist: in afternoon sun and drought the leaves scorch quickly.

Siberian bugloss: when to prune it?

Pruning months: March and June.

When: Little work. In June, cut off the spent flower stems, and in March, remove dead leaves before the new foliage appears.

How:

• Cut the flower stems low after flowering, just above the leaves.
• Remove dead leaves in March, before the new flower buds and leaves appear.
• In summer, cut away scorched or damaged leaves; new ones often grow in their place.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Division

In spring or September: lift the clump and cut it into pieces, each with its own roots and buds.

Root cuttings

In winter: cut 5 cm pieces of thick root and lay them in gritty cutting compost. This works well for the green species; variegated cultivars often give plain green leaves this way.

Seed

The plain species sometimes self-seeds; seedlings of cultivars with patterned leaves rarely resemble the parent.

Siberian bugloss: how does it get through the winter?

Hardy to −35 °C.

• Fully hardy, to about −35 °C: no protection is needed.
• The leaves die back in winter and the plant regrows in March.
• A late frost can damage young leaves and flowers; the plant usually recovers quickly.

Diseases and pests

• Slugs and snails: Holes in young leaves in spring. Pick them off in the evening and leave no hiding places.
• Brown leaf edges: Too much sun or too dry a soil. Water, mulch and if necessary move the plant to more shade.
• Powdery mildew: White powder on the leaves in dry summers. Remove affected leaves and keep the soil moist.
• Reverting: Variegated cultivars sometimes produce plain green shoots. Dig them out, roots and all.

Through the year

• March: Remove dead leaves. Apply compost or leaf mould. Planting.
• April: Flowering. Watch out for slugs. Planting.
• May: Last flowers. Apply a mulch.
• June: Cut off spent flower stems.
• July: Water during dry spells.
• August: Water during dry spells. Cut off scorched leaves.
• September: Planting and dividing.
• October: Planting.
• December: Take root cuttings from the green species.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Did you know?

• Brunnera is named after the Swiss botanist Samuel Brunner, who lived from 1790 to 1844.
• It is related to the true forget-me-not, to comfrey and to borage.
• Its English name is Siberian bugloss, even though it comes from the Caucasus, not Siberia.