Allium sphaerocephalon

round-headed leek or round-headed garlic

Eventual height & spread

Allium sphaerocephalon

round-headed leek or round-headed garlic

  • 1000 × bulbs
  • £62.99 £89.99
  • available to order from summer
  • 25 × bulbs
  • £1.99 £3.99
  • In stock (shipped within 2-3 working days)
  • 2 litre pot | 7 per pot
  • £18.99
  • available to order from spring
  • 2 + 1 FREE 2 litre pots
  • £37.98 £56.97
  • available to order from spring
  • 50 + 25 FREE bulbs
  • £5.59 £7.98
  • available to order from summer
Delivery options
  • Bulbs (only) £4.95
  • Position: full sun
  • Soil: moderately fertile, moist but well-drained soil
  • Rate of growth: average
  • Flowering period: July to August
  • Hardiness: fully hardy
  • Bulb size: 5/-


Elegant and architectural, Allium sphaerocephalon is a snip to grow, and is long-lasting in the garden or vase. With tall, thin flowering stems can grow to nearly a metre in height, this plant will also work well in many planting designs, adding colour, shape, and movement to the display.

Initially first, these plants produce a clump of fragrant, grass-like leaves in late spring, but as the leaves die back, the bulb's energy goes into making the beautiful, egg-shaped flowers.

Summer flowers for colour and structure

Appearing in July and August, the bright green buds open to rich claret-coloured flowers. These flowers then fade to a softer pink, before finally, developing a bleached, papery look and feel.

A beacon for pollinators

Like all alliums, the flowers of the round-headed leek, also known as garlic allium, are full of nectar, and therefore, they'll attract bees, butterflies, other helpful pollinators. This makes them very valuable for supporting the health and diversity of your garden's ecosystem.

Plant a variety of different types of alliums and you can have flowers from April to August. This will add colour to your garden and provide nectar for pollinators.

What can I plant with Allium sphaerocephalon?

Allium sphaerocephalon is very adaptable and easy to use in many ways, and it adapts well to a variety of different planting designs.

Pair them with ornamental grasses to add colour and structure to natural planting schemes, or summer-flowering perennials in both classic cottage and modern garden borders. You can also use them in mixed potted arrangements.

As their leaves die back early in the growing season, gardeners often pair them with spreading or low-growing perennials. Plants like herbaceous geraniums will effectively hide their fading leaves without hampering their flowers.

Being so structural, they also look wonderful with all those perennials that have visibly distinctive flowerheads or flower spikes. For example, the round flowerheads of the sphaerocephalon plant will look great with the upright spires of taller Salvias. They will also pair well with the flat clusters of Achilleas and the spiky heads of Eryngiums.

If you want to use A. sphaerocephalon bulbs to create a wildlife haven, check out our Butterfly Allium collection. It offers nectar-rich flowers from May to August. Top it up with some extra A. neapolitanum Cowanii Group bulbs and the display could start even earlier.

Alternatively, our Shades of purple allium collection contains many of the iconic drumstick forms. Designers love these varieties, and they often appear in Chelsea show gardens, using them to add bright colours and interesting shapes.

Our large collection of 200 alliums provides great value and a nice mix of species. Perfect perhaps if you’re starting off a collection.


  • Garden care:
    Allium sphaerocephalon bulbs are easy to grow in a sunny spot with freely drained soil, or a good quality potting compost. You should ideally plant them in September or October, however gardeners can also plant them in milder areas in early November.

    Dig holes about three times deeper than the bulb's diameter. Place the bulbs in the holes with the pointy side up. Gently fill the holes with soil and water them to help settle the bulbs.

    In early spring, when growth starts, use a balanced, slow-release fertiliser. Let the plants die back naturally before cleaning up.
    • Pets: TOXIC if eaten; Humans: Ornamental bulbs - not to be eaten

    Goes well with