Allium 'Azureum' Blue

25 bulbs
£5.99
£0.24 each
50 bulbs
£10.99
£0.22 each
Save 8%
100 bulbs
£19.99
£0.20 each
Save 17%

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Caesium is Latin for "blue-grey" or "sky-blue," distinguishing its lighter, softer shade from the deeper blue of its relative, Allium azureum.

A jolt of electric, azure-blue for the summer garden, Allium azureum is a gem of startling intensity. Unlike its paler relatives, this allium delivers a spectacular splash of vivid, cornflower-blue, a colour that brings an unparalleled energy to the border. It forms dense, tightly packed globes of star-shaped florets, each held aloft on slender, upright stems that rise above withering, grass-like foliage. This trait makes it a perfect candidate for interplanting, where its brilliant flower heads can float magically above a sea of lower-growing perennials and grasses.

Native to the windswept steppes of Central Asia, it is perfectly at home in full sun and sharply-drained soil. For a truly breathtaking effect, plant in generous, tightly-packed drifts where its collective power can create a dazzling, vibrant haze of blue. Pair it with the contrasting fire of orange geums or the cool silvers of artemisia and eryngium for a display that is both dynamic and sophisticated. A plant of pure, unadulterated colour, Allium azureum is guaranteed to stop onlookers in their tracks.

Botanical name Allium azureum
Flower colour Bright blue
Bulb size 4/+ cm
Established height 40-60 cm
Established spread 5-10 cm
Plant spacing 150-200 bulbs per m²
Leaf colour Green
Habit Upright
Life cycle Perennial
Hardiness Fully hardy
Years to establish 1st year
Sunlight Full sun
Position Sheltered
Suitable for Borders, Gravel gardens
Soil acidity Any
Soil moisture Free draining
Soil type Sandy, Gritty
RHS Award (AGM) Yes
Growing skill Easy to grow
Pollinator-friendly Yes
Deer resistant Yes

Where to Plant:

To achieve the most vibrant cornflower-blue hue, a location in full sun is essential. This allium thrives in free-draining soil and is an excellent choice for gravel gardens or sunny, well-drained borders where it can bake during the summer. Its relatively compact size makes it suitable for the front or middle of a border, and it combines beautifully with silver-leaved plants or other sun-loving perennials. It can also be grown successfully in deep containers.

How to Plant:

Plant bulbs in the autumn. As they are smaller bulbs, a planting depth of about 10-15cm is sufficient. Space them roughly 8-10cm apart to create a dense and impactful clump of colour. Grouping them together in clusters of ten or more will create a stunning blue spectacle in early summer. If planting in pots, use a loam-based compost mixed with grit to ensure excellent drainage.

Aftercare:

Once established in the ground, they are very low-maintenance and will not need routine watering. For those in containers, water regularly during the growing season but ensure the compost does not become waterlogged. There is no need to deadhead the flowers; the faded, papery seed heads continue to provide structural interest long after the colour has faded. Allow the leaves to wither and die back completely before removing them.

Planting and Flowering Calendar

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Key Features

Packed in paper

Packed peat-free

Great for Shade

Attracts wildlife

RHS Award (AGM)

Naturalising

Allium 'Azureum' Blue - Harding & Bloom

Allium 'Azureum' Blue

£5.99

£5.99

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Kind Words from Our Gardeners

Arrived quickly and well-packaged. Planted them in some pots on the patio and they all came up. Look beautiful. Thank you!

Careane Wallace

Oxfordshire, UK

The bulbs arrived beautifully packaged and you could just tell they were excellent quality. We had the most wonderful display of daffodils this spring on our patio. Simply stunning. Will definitely be ordering again

David P

Kent, UK

I ordered the mixed hyacinth collection and the scent in my garden this April was absolutely heavenly. Every single bulb produced a strong, beautiful flower and the colours were stunning together. A fantastic purchase, I'll be back for more next year!

Eleanor R

Somerset