Admirable pots
Alliums are happy in containers as long as they are deep enough for the bulbs to be planted at three times their depth, with a 4-5cm-deep bed of compost beneath them (any peat-free multipurpose compost will do). Varieties with shorter, sturdier stems are best, such as Star of Persia (Allium cristophii). It reaches 50cm and has ‘starbursts’ of metallic silvery-purple flowers and fabulous seed heads. Underplant with grasses or trailing nepeta.