Allium senescens subsp. glaucum

RHS Plant Profile
corkscrew onion

Synonyms

Allium senescens var. glaucum
Allium glaucum
Allium senescens subsp. montanum var. glaucum

Bulbs

A bulbous, herbaceous perennial up to 20cm high, producing tufts of twisted, grass-like grey-green leaves to 25cm wide, and pink flowers from June to September

Position

Full sun

Soil Types

Chalk, Loam, Sand

Max Height

0.1-0.5 metres

Max Spread

0.1-0.5 metres

Size

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

Growing Conditions

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

Position

Full sun
Aspect
East–facing or South–facing or West–facing
Exposure
Exposed or Sheltered
Hardiness
H6
Drought Resistance
Yes

Colour & Scent

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
Siberia to Mongolia

How to Grow

Cultivation

Grow in well-drained soil in full sun; for more advice see allium cultivation

Propagation

Propagate by seed or by division during spring or autumn

Suggested planting locations and garden types

  • City and courtyard gardens
  • Cottage and informal garden
  • Gravel garden
  • Patio and container plants
  • Rock garden
  • Wildlife gardens
  • Low Maintenance

Pruning

No pruning required

Pests

May be susceptible to damage by slugs and snails

Diseases

May be susceptible to onion white rot and downy mildews