Allium unifolium

allium or American onion bulbs

Eventual height & spread

Allium unifolium

allium or American onion bulbs

  • 25 × bulbs
  • £9.99 £0.40 each
  • available to order from autumn
  • 75 × bulbs
  • £27.00 £0.36 each
  • available to order from autumn
Delivery options
  • Bulbs (only) £4.99
  • Position: full sun
  • Soil: moderately fertile, moist but well-drained soil
  • Rate of growth: average
  • Flowering period: May to July
  • Hardiness: frost hardy (may need winter protection)
  • Bulb size: 5/-


The flowers of Allium unifolium have a papery texture, which means they tend to last a little longer than many of the other cultivars.

In spring the first sign of growth is the appearance of the strappy foliage, although this will usually have died off by the time the flowers start to appear in late spring.

Topping slender stems from late spring to midsummer, the pinky purple, bell shaped flowers form in clusters of up to 20 at a time. Attractive to a wide range of pollinators and equally pretty in borders, pots or vases, they make terrific additions to border edges and alpine beds.


  • Garden care:
    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.

    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.
    • Pets: TOXIC if eaten; Humans: Ornamental bulbs - not to be eaten

    Goes well with