Allium fistulosum 'Ishikura'

RHS Plant Profile
onion (salad) 'Ishikura'
onion (salad) 'Ishikura' Michael John Day

Synonyms

Allium cepa 'Ishikura', Allium fistulosum 'Ishikura'

Award of Garden MeritPlants for pollinators
Bulbs Herbs - Culinary

Evergreen, perennial onion, grown as an ornamental in the herb or wildlife garden or as an annual vegetable, forming clumps of elongated, straight white stems and hollow green leaves. Exceptionally long harvest period from summer to autumn without the need for successive sowings. In their second year, the bulbs produce spherical heads of densely clustered greenish-white flowers on stems to 60cm high in early and midsummer

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
1–2 years
Max Spread
0.1-0.5 metres
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
South–facing or West–facing
Exposure
Sheltered
Hardiness
H5

Colour & Scent

Fragrance Foliage Stem
Season Stem Flower Foliage Fruit
Spring
Summer
Autumn
Winter

Botanical Details

Family
Amaryllidaceae
Native to GB/Ireland
No
Foliage
Evergreen
Habit
Clump forming
Potentially harmful
TOXIC to pets (dogs and cats). See the HTA guide to potentially harmful plants for further information and useful contact numbers
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
Accepted

How to Grow

Cultivation

Easy to grow in full sun and a 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. See sowing vegetable seeds

Suggested planting locations and garden types

  • Cottage and informal garden
  • Patio and container plants
  • Wildlife gardens

Pruning

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

Pests

May be susceptible to allium leaf miner and onion fly

Diseases

May be susceptible to onion white rot, and onion downy mildew