A picture of a Ornamental Onion

Ornamental Onion

Allium caeruleum

Also known as

Blue-Of-The-Heavens, Azure-Flowered Garlic, Blue Allium

Allium caeruleum 2 by http://www.fleurs-des-montagnes.net (CC BY-SA 3.0)

Full Sun
Moderate care
Light watering
Frost Hardy

8a

USDA zone

-12°C

Minimum temperature

Expected size

Height
Spread

1m

Max

30cm

50cm

Min

10cm

3 years to reach maturity

Flowering

  • spring
  • summer
  • autumn
  • winter

More images of Ornamental Onion

A close up of some blue Allium caeruleum flowers
Some blue Allium caeruleum flowers
A close up of some blue Allium caeruleum flowers
A photo of Ornamental Onion

Ornamental Onion Overview

Allium caeruleum is a bulbous perennial species that typically grows to around 80cm tall. It produces linear mid-green leaves, which clasp the stems and showy, blue blooms. Flowers are arranged on dense rounded heads on vertical, stiff stems, they are bright blue, small and star-shaped. Flower appear from early summer. This species originates from Central Asia, it can be found in the wild across dry slopes, plains and steppes from the Caspian Sea to southwestern Siberia, it is also found in Turkestan and northwestern China. Grows best in full sunshine, in a sheltered position and in a moist and well-draining soil. This species is part of the Royal Horticultural Society “Plants for Pollinators” initiative to showcase plants which support pollinator populations by providing ample amounts of nectar and/ or pollen. A great choice for encouraging pollinating insect wildlife into your garden!

Common problems with Ornamental Onion

Generally pest and disease free, can be affected by onion white rot and powdery mildew.

How to propagate Ornamental Onion

Seed

Propagate by seed, sowing in containers in a cold frame when just ripe or in the spring.

Division

Remove offsets in autumn.

Special features of Ornamental Onion

Attractive flowers

Attracts butterflies

Attracts bees

Attracts useful insects

Other uses of Ornamental Onion

Suited to flower borders and beds. Makes a lovely cut flower for floral arrangments. Also looks great underplanted with roses and other shrubs in a cottage & informal garden setting.