Allium 'Cowanii' (Neapolitan garlic (Cowanii Group))

Delivery begins from 14 September 2026
Spring flowering bulbs and plants are scheduled to begin delivery from 14 September 2026.

50 bulbs
£4.89
£0.10 each
100 bulbs
£9.49
£0.09 each
Save 3%
250 bulbs
£21.69
£0.09 each
Save 11%

Delivery begins from 14 September 2026

Carbon-Neutral Delivery

Our "Bloom or Bust" Promise

Cowanii, often admired for its white colouring, is a bulb variety especially well suited to borders.

Allium cowanii (Neapolitan garlic, Cowanii Group) is a quietly captivating allium, sending up loose, airy umbels of pure white, starry flowers on slender stems. Flowering in late spring and early summer, it brings a clean, lifted note to borders, gravel planting and pots—especially effective when threaded through grasses or soft, cottage-style perennials.

Compact and clump-forming, it settles in with ease and returns reliably year after year. Plant in autumn for an elegant drift of white that also proves popular with pollinators.

  • Flower colour: White
  • Flowering period: May–June
  • Best for: Borders, containers, cottage gardens, city gardens
  • Character: Airy, star-shaped flowers with a refined, natural look
Botanical name Allium cowanii
Flower colour White
Bulb size 5/6cm
Established height 40cm
Established spread 10cm
Plant spacing 10cm
Leaf colour Green
Habit Clump-forming
Life cycle Perennial
Hardiness Fully Hardy
Years to establish 2
Sunlight Full-Sun, Partial Sun
Position South-facing, West-facing
Suitable for Borders, Containers, Cottage Gardens, City Gardens
Soil acidity Any
Soil moisture Well-drained
Soil type Clay
RHS Award (AGM) No
Growing skill Easy
Pollinator-friendly Yes
Deer resistant No

Where to Plant:

Allium 'Cowanii' (Neapolitan garlic (Cowanii Group)) needs full-sun, partial sun and a warm, sheltered position for the best flowering. Plant into fertile, humus-rich soil that drains well, and choose a spot protected from strong winds, especially for taller varieties.

How to Plant:

Plant bulb from September to December once conditions are suitable. Set them at the correct depth for the variety, spacing 10cm apart where relevant, then firm in gently and water well after planting.

Aftercare:

Water regularly in dry weather and feed every two to three weeks once buds appear. Stake taller stems early and deadhead to keep plants flowering. After flowering, allow foliage to die back naturally before lifting or protecting bulb according to local conditions.

Planting and Flowering Calendar

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Planting
Flowering

Key Features

Packed in paper

Packed peat-free

Great for Shade

Attracts wildlife

Good for cutting

Naturalising

Allium 'Cowanii' (Neapolitan garlic (Cowanii Group)) - Harding & Bloom

Allium 'Cowanii' (Neapolitan garlic (Cowanii Group))

£4.89

£4.89

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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