Siberian squill

Sun

Full sun to partial shade; well suited to the spring light beneath deciduous trees.

Water

Moderate moisture while growing in spring; usually needs little watering once dormant in summer.

Soil

Well-drained soil with some organic matter; tolerates clay if it does not remain waterlogged.

Height

0.25-0.5 ft (0.08-0.15 m)

Spread

0.25-0.5 ft (0.08-0.15 m) per clump; colonies can spread much farther

Flowers

Early to mid-spring; usually vivid blue, with white-flowered forms also available.

Foliage

A few narrow, glossy green, strap-shaped leaves emerge in spring and die back by early summer.

Growth

Quick spring growth; colonies expand steadily by offsets and self-seeding.

Care needed

Low

• Pollinators
• Deer resistant
• Cold hardy
• Low allergen

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Easy

Toughness

Very tough

Pick your zone, country, light and whether you have pets.

1. Planting day

   0.4 ft (0.12 m)

   full size

About 1 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Toxic

Invasive in

the US and Canada

In the garden

Spreads vigorously: plan to contain it.

• Plant bulbs in autumn, about 3 in (8 cm) deep and 3 in (8 cm) apart.
• Water during prolonged dry spells while leaves are green; avoid soggy soil.
• Leave foliage intact until it yellows naturally so the bulbs can replenish their reserves.
• Apply a thin layer of compost in autumn; routine feeding is rarely necessary.
• Divide crowded clumps as the foliage yellows, and replant promptly.
• Remove developing seed capsules if you need to limit spread; avoid planting where it is locally invasive.

Pruning. No routine pruning is needed. Remove flower stems before seeds ripen to reduce self-seeding, and remove leaves only after they have yellowed completely.

Autumn

Plant bulbs in well-drained soil, away from natural woodland where escape is a concern.

Late winter

Check emerging shoots and make sure pots or planting pockets are not waterlogged.

Early spring

Water during unusually dry weather while plants are flowering and producing leaves.

Mid-spring

Remove spent flower stems before seed capsules mature if spread is unwanted.

Late spring

Lift and divide crowded clumps as their leaves begin to yellow.

Summer

Remove fully dead foliage and avoid unnecessary watering of dormant bulbs.

• Plant small groups beneath deciduous shrubs for blue flowers before the canopy fills out, where local invasive guidance permits.
• Edge a spring border with squill, snowdrops and early crocuses for a low sequence of flowers.
• Place among hostas or deciduous ferns, whose later foliage conceals the dying bulb leaves.
• Grow in outdoor containers for close-up spring colour, removing seed capsules before they open.

Garden styles it suits: Woodland, Cottage garden, English country, Traditional, Blues and silvers and Low-maintenance.

Plant it with: Snowdrops, Early crocuses, Hellebores, Hostas, Lungwort and Lady fern.

Wildlife: Flowers provide early pollen and nectar for visiting bees. In regions where it invades woodland, dense colonies can compete with native spring plants; choose locally native spring bulbs or wildflowers there.

• Bulb rot in wet soil: improve drainage or move bulbs to a raised planting area; discard soft, rotten bulbs.
• Unwanted seedlings and expanding colonies: remove seed capsules, dig out bulbs and repeat removal over several seasons; do not dump bulbs or seeded soil in natural areas.
• Poor flowering in heavy shade or warm climates: provide more spring sunlight; this bulb performs best with a cold winter and may be unreliable in warm-winter districts.
• Slugs and snails eating shoots or flowers: check plants in damp weather and hand-pick pests or use a locally approved iron-phosphate bait.

Treat all parts, especially the bulbs, as poisonous to people, cats, dogs and horses. Ingestion can cause vomiting, diarrhoea and potentially serious effects on heart function. Keep bulbs away from children and animals, and seek prompt medical or veterinary advice after ingestion.

Where it spreads. Spreads by seed and bulb offsets. It is considered invasive in parts of the northern United States, particularly Minnesota, Wisconsin and Michigan, and in parts of southern Ontario, Canada, where it can colonize woodland. Check local guidance before planting near natural areas.

• Glory-of-the-snow (Scilla luciliae)

  Its flowers face upward or outward and have a conspicuous white centre; Siberian squill usually has nodding, bell-shaped blue flowers.

• Striped squill (Puschkinia scilloides)

  Its flowers are pale blue to almost white with a darker blue stripe down each segment, rather than the usually strong blue of Siberian squill.

• Alpine squill (Scilla bifolia)

  It usually has two leaves and clusters of open, upward-facing starry flowers; Siberian squill has more bell-shaped, downward-facing flowers.

Scilla comes from an ancient Greek name for squill, while siberica means 'Siberian', although the species is native farther southwest rather than to Siberia.

Propagation. Separate bulb offsets as foliage yellows in late spring, or lift dormant bulbs in summer and replant promptly. Fresh seed can be sown outdoors, but seedlings take several years to flower and may spread beyond the intended area.

Accepted botanical name

Scilla siberica

In the US and Canada

Introduced in Canada and the lower 48 states.

Native range

Central European Rus, East European Russia, Iran, Iraq, Krym, Lebanon-Syria, North Caucasus, South European Russi, Transcaucasus, Turkey and Ukraine.

Measured

Soil pH 5.5 to 6.5. Average height 15 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.