Summer hyacinth

Sun

Full sun; tolerates light shade, but flowering is usually better in sun.

Water

Water regularly during active growth, allowing the surface soil to dry slightly between waterings. Keep dormant bulbs relatively dry, never waterlogged.

Soil

Fertile, well-drained soil enriched with compost; tolerates a range of soil pH. Avoid heavy soil that stays wet through winter.

Height

3-5 ft (0.9-1.5 m)

Spread

1-2 ft (0.3-0.6 m)

Flowers

White, sometimes green-tinged, nodding bells in late summer to early autumn.

Foliage

Broad, fleshy, strap-shaped green leaves in a basal clump; dies back for winter.

Growth

Moderate; established bulbs gradually form larger clumps.

Care needed

Medium

• Pollinators
• Heat tolerant
• Low allergen
• Fragrant

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

Difficulty

Moderate

Toughness

Fairly tough

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

1. Planting day

   0.5 ft (0.15 m)

2. After 1 year

   4 ft (1.2 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

Growth rate

Moderate

• Plant bulbs in spring, about 4-6 in (10-15 cm) deep and 8-12 in (20-30 cm) apart.
• Water during dry spells while leaves and flower stems are growing, without leaving the soil saturated.
• Apply compost and a balanced fertiliser as growth starts in spring.
• Stake flower stems early if the site is exposed to strong winds.
• Mulch over winter in marginally hardy gardens; in colder regions, lift dormant bulbs and store them cool, dry and frost-free.
• Divide crowded clumps in spring only when flowering declines or you want more plants.

Pruning. Cut spent flower stems down near the base unless you want seed. Leave the leaves until they have yellowed and died back naturally, then remove them.

Spring

Plant stored or purchased bulbs once the ground is workable and severe frosts have passed.

Spring

Feed established clumps as leaves emerge; divide overcrowded bulbs before substantial growth develops.

Early summer

Water during dry weather and put supports in place on exposed sites.

Late summer

Enjoy the flowers and remove fading stems if seed is not wanted.

Autumn

Let foliage yellow naturally, then clear away the dead leaves.

Late autumn

Mulch bulbs left outdoors, or lift and store them frost-free where winters are too cold or wet.

• Plant small groups through the middle or back of a sunny border for narrow, upright flower accents.
• Combine with ornamental grasses for white bells above a soft, moving base.
• Use in a white garden with white phlox and silver-leaved plants for late-summer continuity.
• Grow in large, well-drained containers where winter shelter is easier to provide.

Garden styles it suits: English country, Cottage garden, White garden, New perennial (prairie), Romantic rose garden and Modern courtyard.

Plant it with: Garden phlox, Purple coneflower, Switchgrass, Catmint, Salvia and Gaura.

Wildlife: The flowers attract visiting insects, including bees. It is not a native plant in the United States, the United Kingdom, Canada or Australia.

• Bulb rot in wet winter soil: improve drainage, use a raised bed or container, or lift bulbs for dry winter storage.
• Slugs and snails damaging emerging leaves: check new shoots regularly and use barriers, hand-picking or an appropriate labelled bait.
• Poor flowering in shade or crowded clumps: move bulbs to a sunnier position and divide congested clumps in spring.
• Frost damage or loss of bulbs: mulch in marginal areas and lift for frost-free storage where winters regularly exceed its tolerance.

Species-specific toxicity information is limited. Other Ornithogalum species contain toxins that can affect the heart, so do not assume this species is safe for people, cats, dogs or horses to eat. Keep bulbs and other plant parts out of reach, and seek medical or veterinary advice after ingestion; the severity for this species is not well established.

• Green summer hyacinth (Ornithogalum viridiflorum)

  Has greenish flowers rather than the predominantly white bells of summer hyacinth; also sold under its older name, Galtonia viridiflora.

• Giant chincherinchee (Ornithogalum saundersiae)

  Carries rounded clusters of upward- or outward-facing white stars with conspicuous dark centres, rather than a long spike of hanging bells.

• Garden hyacinth (Hyacinthus orientalis)

  Flowers in spring on much shorter, densely packed spikes; summer hyacinth has tall, loose spikes later in the year.

The epithet candicans means becoming white or shining white, referring to the flowers, while summer hyacinth describes their resemblance to hyacinth flowers and their later season.

Propagation. Separate offsets from established bulbs in spring and replant promptly. Alternatively, sow ripe seed in a protected container; seedlings usually take several years to reach flowering size.

Accepted botanical name

Ornithogalum candicans

Native range

Cape Provinces, Free State, KwaZulu-Natal, Lesotho and Northern Provinces.

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