These are onions with large heads of flowers, usually spherical, with the pointed petals giving the famed ‘exploding firework’ effect. In many of them the flower heads dry in the autumn, and can be used as spectacular Christmas decorations. Flowers are usually pink, purple or white, and leaves may be present at flowering time, or come earlier, withering as the flowers open. In the latter case, cut them back as the flowers start to open.These are onions with large heads of flowers, usually spherical, with the pointed petals giving the famed ‘exploding firework’ effect. In many of them the flower heads dry in the autumn, and can be used as spectacular Christmas decorations. Flowers are usually pink, purple or white, and leaves may be present at flowering time, or come earlier, withering as the flowers open. In the latter case, cut them back as the flowers start to open.

Allium 'Firmament' has dark purple flowers.