loading

Allium giganteum

ornamental onion or allium bulb

Product Image
Dense globes of small, star-shaped, lilac-pink flowers on towering stems in summer above pale green leaves, which starts to die back before the flowers appear. This gorgeous ornamental onion - the tallest currently available - is perfect for providing vertical interest in a sunny border. Try it dotted in small groups among ornamental grasses, or as part of a Mediterranean scheme.

How to care for Allium giganteum:

Allium bulbs are easy to grow in a sunny spot with freely drained soil, or a good quality potting compost. Ideally they should be planted in September or October, but could also be planted in early November in milder regions. While keeping the size of the flowerhead in mind and avoiding overcrowding, dig holes roughly three times as deep as the diameter of the bulb and place them at the base, pointy side up before gently infilling and watering to settle them in. In early spring, as growth begins, apply a balanced, slow-release fertiliser, and allow the plants to die back naturally and completely before tidying away.
Flowering period:
  • Jan
  • Feb
  • Mar
  • Apr
  • May
  • Jun
  • Jul
  • Aug
  • Sep
  • Oct
  • Nov
  • Dec
Eventual height:
1.8m
Eventual spread:
0.15m
Position:

Full sun

Rate of growth:

Average

Soil:

Moderately fertile, moist, well-drained soil

Hardiness:

Fully hardy

  • InformationThis perennial dies back to below ground level each year in autumn, then fresh new growth appears again in spring.
  • InformationPets: TOXIC if eaten; Humans: Ornamental bulbs - not to be eaten

Product options

Product options image
PL00000188
2 litre pot | 1 per pot
£18.99
available to order from spring
Product options image
PL30007436
2 + 1 FREE 2 litre pots
was £56.97 now £37.98
available to order from spring
Product options image
BU30000230
1 × bulb
£7.99
available to order from summer
Product options image
BU30001127
3 × bulbs
was £23.97 now £21.00
available to order from summer
Delivery options (pick your preferred option at checkout)
Standard delivery Standard Delivery£5.95

Goes well with

Become an RHS Member today and save 25% on your first year