Allium cristophii - 2 litre pot £6.00 Sorry, this plant is currently out of stock. Large globes of lilac, star-shaped flowers in early summer. Sun or part shade, well-drained soil. H: 50cm AGM Flowers up to 20cm wide make a real impact in a mixed border or in pots. They look fantastic planted amongst silver-leaved plants, such as Artemisia 'Powis Castle'.