BBC Gardeners' World

Plant details

• Common Name: Ornamental onion
• Genus: Allium
• Species: giganteum
• Skill Level: beginner
• Exposure: full sun
• Soil type: well-drained/light
• Height: 1.5m
• Spread: 0.15m

This beautiful ornamental onion produces dense heads of lilac-pink, star-shaped flowers in summer. Its tall stems make it ideal for planting among lower-growing perennials where it can add an extra dimension to your planting. The Royal Horticultural Society has given the plant its prestigious Award of Garden Merit (AGM) which is for plants of outstanding excellence. Plant the bulbs 5cm to 10cm (2in to 4in) deep in autumn.