Allium caesium

RHS Plant Profile
light blue garlic

Synonyms

Allium urceolatum

Award of Garden MeritPlants for pollinators
Bulbs

Bulbous perennial about 50-60cm tall, with dainty, very slender grey-green leaves and dense flowerheads, 2cm in width, composed of green-veined, violet-blue flowers in late spring and early summer

Position

Full sun

Soil Types

Chalk, Loam, Sand

Max Height

0.1-0.5 metres

Max Spread

0-0.1 metre

Size

Time to Maturity
2–5 years
Max Spread
0-0.1 metre
Max Height
0.1-0.5 metres

Growing Conditions

Chalk Loam Sand
Moisture
Moist but well–drained or Well–drained
pH
Acid or Alkaline or Neutral

Position

Full sun
Aspect
East–facing or South–facing or West–facing
Exposure
Sheltered
Hardiness
H5

Colour & Scent

Fragrance Foliage
Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Amaryllidaceae
Native to GB/Ireland
No
Foliage
Deciduous
Habit
Clump forming
Genus
Allium are bulbous herbaceous perennials with a strong onion or garlic scent, linear, strap-shaped or cylindrical basal leaves and star-shaped or bell-shaped flowers in an umbel on a leafless stem
Name Status
Correct
Plant Range
C Asia

How to Grow

Cultivation

Grow in full sun and fertile well-drained soil. It is best to grow in containers where garden soil is heavy clay and prone to saturation over winter. See allium cultivation

Propagation

Propagate by seed when just ripe or in spring; or propagate by offsets which can be carefully detached by lifting the bulb after flowering has finished. See bulb propagation

Suggested planting locations and garden types

  • City and courtyard gardens
  • Rock garden
  • Wildlife gardens
  • Coastal
  • Cottage and informal garden
  • Gravel garden
  • Patio and container plants
  • Cut flowers
  • Flower borders and beds

Pruning

No pruning required, other than to remove old flowered stems and foliage

Pests

Susceptible to allium leaf miner and onion fly

Diseases

May be susceptible to onion white rot and downy mildews