Allium Firmament (Ornamental Onion)

Regarded by some as one of the very best, Allium ‘Firmament’ is a rather unusual Allium. Instead of having round flowerheads, it is only two-thirds of the sphere, about 4-5 in. wide (10-12 cm). It is packed with star-shaped, dark silvery purple flowers, each flower being comprised of dark purple florets adorned with shimmering silver anthers.

Regarded by some as one of the very best, Allium 'Firmament' is a rather unusual Allium. Instead of having round flowerheads, it is only two-thirds of the sphere, about 4-5 in. wide (10-12 cm). It is packed with star-shaped, dark silvery purple flowers, each flower being comprised of dark purple florets adorned with shimmering silver anthers. Blooming from late spring to early summer, this striking bulbous perennial enjoys a long-lasting season of interest and remains ornamental in the garden well into summer. A lovely cross between Allium christophii and Allium atropurpureum.

  • Growing up to 24-30 in. tall (60-75 cm), this beauty naturalizes easily and will come back year after year!
  • Easily grown in rich, sandy to gritty, dry to medium moisture, well-drained soils in full sun. This Allium is drought tolerant.
  • Known for attracting bees, butterflies, ​moths, and other pollinators, but deer ignore it.
  • Stunning in beds, borders, and cottage gardens. Spectacular in large sweeping drifts. Plant in groups (at least 10 to 15 bulbs) for the best visual impact. Excellent as cut flowers for both fresh and dried arrangements!
  • Mixes beautifully with other late spring flowering bulbs and creates stunning combinations with pink or white delphiniums, peonies, or irises.
  • To be planted in fall.

Requirements

Hardiness 5
– 8

Climate Zones 1, 1A, 1B, 2, 2A, 2B, 3, 3A, 3B, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24
Plant Type Bulbs
Plant Family Allium
Exposure Full Sun
Season of Interest Spring (Late)Summer (Early)
Height 2'
– 3'
(60cm
– 90cm)
Spread 1'
– 2'
(30cm
– 60cm)
Spacing 8″ (20cm)
Depth 8"
(20cm)
Water Needs Average
Maintenance Low
Soil Type Chalk, Clay, Loam, Sand
Soil pH Acid, Alkaline, Neutral
Soil Drainage Moist but Well-Drained, Well-Drained
Characteristics Dried Arrangements, Cut Flowers, Fragrant, Showy
Tolerance Deer, Drought, Rabbit
Attracts Bees, Butterflies
Garden Uses Beds and Borders
Garden Styles Formal Garden, Informal and Cottage