Allium azureum

As flower colours go, true blue can be hard to find. Gardeners with foresight will have planted the bluest of the blue-flowering bulbs in time to get a flush of azure, and they’ll have chosen the blue Allium azureum (also known as Allium caeruleum) for a showy display of blue pompom-pop like clusters of florets.

Awarded the prestigious Award of Garden Merit by RHS, Allium Caerulium is a stunning ornamental onion. This variety consists of dozens of small star-shaped bright blue flowers, forming a globe shaped cluster atop of sturdy stiff stems with narrow green leaves. Prized for its true blue colour, Allium Caerulium flowers in the garden in late spring to early summer. Growing up to 30-60cm tall, Allium Caerulium forms dense, slowly-spreading clumps over time. It naturalises easily and will come back year after year! Since the leaves wither before the flowers appear, plant your Allium Caerulium with other mid-sized plants to hide the faded foliage.

The stems of Allium azureum are quite tall, so you can use these blue alliums as a striking background for your summer perennials, or you can plant them on their own to create a splash of bluer-than-blue colour. With those looks, you may be pardoned for wondering whether these plants will need a little extra pampering, but these blue alliums are not delicate, hothouse beauties. Simply plant them, add water, and enjoy!

Instructions for planting

• Plant 10cm deep and at least 5cm apart 
• Easily grown in rich, sandy-gritty, dry to medium moisture, well drained soils
• Performs best in full sun
• Stunning in beds, borders, cottage gardens.
• Spectacular in large sweeping drifts. For best visual impact plant in groups of at least 10-15 bulbs
• Mixes beautifully with other late spring flowering bulbs and creates stunning combination with pink or white varieties (Delphiniums, Peonies or Irises)