Allium caeruleum - blue allium bulbs (syn. Allium azureum)

Position: full sun

Soil: fertile, well-drained soil

Rate of growth: average

Flowering period: June to July

Hardiness: fully hardy

Allium bulb size: 4/- This stunning blue ornamental onion is ideal for a sunny border. Dense globes of small, star-shaped, bright blue summer flowers on stiff stems and narrow, mid-green leaves. Since the leaves die back before the flowers emerge it’s best planted with other medium-sized herbaceous plants, such as sea holly, which help to mask the faded foliage.

Garden care: Plant 8cm (3in) deep in naturalistic drifts in September or October in a well-drained, sunny site. Split and divide large clumps in autumn or spring.