Alphabetical Plant Listing

Allium caesium (Ornamental Onion)

Light Blue Garlic, Allium urceolatum, Flowering Onion, Ornamental Onion, Spring Bulbs, Spring Flowers


Award-winner Allium caesium (Light Blue Garli) is a stunning bulbous perennial boasting globe-shaped clusters, 1 in. wide (2 cm), packed with dozens of small star-shaped sky-blue flowers. They attract pollinators such as bees and butterflies and sit atop stiff stems above the foliage of slender green leaves. Prized for its true blue color, Allium caesium provides interesting ornamental value in the garden from late spring to early summer.

  • Recipient of the prestigious Award of Garden Merit by the Royal Horticultural Society.
  • Grows up to 10-20 in. tall (25-50 cm). Allium caesium will naturalize and come back year after year in optimum growing conditions.
  • Thrives in fertile, dry to medium moisture, well-drained soils in full sun. Add grit to clay soils to improve drainage. This Allium is drought-tolerant once established.
  • Known for attracting bees, butterflies, ​moths, and other pollinators, but deer and rodents ignore it.
  • Stunning in beds and borders, city gardens, coastal gardens, rock gardens, 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.
  • No serious pest or disease issues. Keep an eye out for onion fly, onion white rot, and downy mildew.
  • Propagate by seed sown in containers in a cold frame when ripe or in the spring or remove offsets in autumn
  • Allium caesium is native to central Asia (Xinjiang, Kazakhstan, Kyrgyzstan, Tajikistan, Uzbekistan) where it grows in deserts and dry fields at elevations of 700–2,000 m (2,300–6,600 ft).

Hundreds of Allium species exist, but only a few have made a name for themselves as garden plants. The ornamental onions distinguish themselves by their remarkable diversity in color, inflorescence, and flowering height. Many species bloom in early summer - just after the spring-flowering period and just before the exuberant full bloom of summer. Certain small species are just perfect for a rock garden, and several lend themselves to naturalizing. All species can be used in the border.

Learn How To Plant And Care for Your Spring Flower Bulbs

 To achieve optimum flowering results, it is important to plant the bulbs at the right time.

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Requirements

Hardiness 4 – 7
Plant Type Bulbs
Plant Family Allium
Exposure Full Sun
Season of Interest Spring (Late)
Summer (Early)
Height 10" – 2' (25cm – 60cm)
Spread 6" – 8" (15cm – 20cm)
Spacing 2" (5cm)
Depth 4" (10cm)
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 Cut Flowers, Fragrant, Plant of Merit, Showy
Tolerance Deer, Drought, Rabbit
Attracts Butterflies
Garden Uses Beds and Borders
Garden Styles City and Courtyard, Coastal Garden, Gravel and Rock Garden, Informal and Cottage, Mediterranean Garden

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Great Plant Combination Ideas with Allium

Guides with Allium


Sarycheva Olesia, Aleksandr Naumenko, Shutterstock

While every effort has been made to describe these plants accurately, please keep in mind that height, bloom time, and color may differ in various climates. The description of these plants has been written based on numerous outside resources.


Requirements

Hardiness 4 – 7
Plant Type Bulbs
Plant Family Allium
Exposure Full Sun
Season of Interest Spring (Late)
Summer (Early)
Height 10" – 2' (25cm – 60cm)
Spread 6" – 8" (15cm – 20cm)
Spacing 2" (5cm)
Depth 4" (10cm)
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 Cut Flowers, Fragrant, Plant of Merit, Showy
Tolerance Deer, Drought, Rabbit
Attracts Butterflies
Garden Uses Beds and Borders
Garden Styles City and Courtyard, Coastal Garden, Gravel and Rock Garden, Informal and Cottage, Mediterranean Garden

Great Plant Combination Ideas with Allium

Guides with Allium

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