Allium sphaerocephalon is a quite unique, summer-flowering plant that prized by gardeners because of its striking floral display. Each slender stem reaches between 60 and 90cm (2 to 3ft) tall, drifted through borders they provide light vertical accents.
The tall slender stems are topped by an oval head, as opposed to the usual conical sphere. The flowers start off completely chartreuse-green before turning claret at the tip and finally becoming overall deep maroon-claret.
The spherical head, which is technically an umbel, can contain hundreds of deep purple flowers, which provide a welcome nectar stop for bees and other pollinating insects. They are a must for any garden design aimed at encouraging bees into the garden.
The plants flower at the beginning of July, much later-flowering than most purple and lavender alliums and invaluable for that. The flowers last for weeks before fading in the autumn.
Like most bulbous plants, Allium sphaerocephalon do best in sunny, well-drained positions. They are easy to grow and are perfectly hardy, they will come back year after and they are not aggressive self seeders - like some ornamental alliums.
Planted en-masse in a border in full sun, scatter them amongst perennials aiming to form a ribbon of colour. Alternatively you can pot them up in fives or sevens and plant them out to fill any gaps.
The claret flowers are at their best planted amongst perennials where they contrast strongly in form and texture, such as with flat topped Achilleas. The tall stems are also good at adding colour and movement to the garden, they look wonderful emerging from a screen of foliage or when planted against a backdrop of softly swirling, ornamental grasses.
Sowing: Sow at any time of year.
The seeds can be sown directly where they are to flower at any time of year, or can be sown indoors, the seedlings over wintered in the greenhouse and then planted out in the following spring.
Allium seeds need a period of moisture and cold after harvest before they will germinate, usually this is necessary to either allow the embryo to mature or to break dormancy.
If sown indoors in warmer weather, the period of dormancy can be artificially stimulated by placing the moistened seed in a refrigerator. It is best to sow them on moistened, well draining compost, seal the container in a polythene bag and leave everything in the refrigerator for 3 to 5 weeks at around 4 to 5°C (39 to 41°F). The seeds must be moist whilst being pre-chilled, but it doesn't usually benefit them to be actually in water or at temperatures below freezing. After prechilling bring out of the fridge to 13 to 16°F (55 to 60°F)
Light seems to be beneficial and so pre-chilled seeds should have only the lightest covering of compost over them, and the seed trays etc. should be in the light. Compost should be kept moist but not wet at all times. Germination should occur 18 to 21 days.
Prick out each seedling as it becomes large enough to handle, transplant into 7.5cm (3in) pots or trays to grow on. Gradually acclimatise to outdoor conditions for 10 to 15 days before planting out.
Plant out in spring into fertile, well drained soil. Add grit when grown in clay soils to improve drainage. Remember that the foliage dies back as flowering commences; you may wish to place this behind a smaller plant to disguise its foliage. When planting try to plant in groups of at least 3 or 5 as they do look much better in clumps.
Prepare the soil prior to planting by cultivating up to 30cm of soil, on heavier soils add a couple of handfuls of grit under each Allium before planting to improve drainage. Alliums grow well in most soil types but do prefer to be planted in well-drained sunny spots. The bulbs of Alliums vary tremendously in size so the best advice on planting depth is to plant Allium bulbs at a depth of three to four time their depth in the soil. On light soils, increase the planting depths to help anchor the taller varieties. The soil around Alliums should be kept moist during the flowering period.
Alliums in pots:
To plant in pots ensure you have a sturdy deep container (the height and weight of the taller alliums will cause smaller containers to topple over), put crocks in the bottom to allow for drainage and then add about 10cms of potting compost. Place the Allium bulbs on top of the compost so that they are not touching the outside pot or each other. Cover with at least 20cms of potting compost and firm down. During the winter months ensure the compost is kept moist but not too wet and protect from frost. When you see the first signs of growth in the spring (March-April) increasing the amount of water to ensure the compost does not dry out.
Cottage/Informal Garden, Flower Arranging, Flowers Borders and Beds, Gravel Garden or Rock Garden.
Alliums can be left undisturbed from year to year and as long as they are well fed will continue to flower. If you do need to lift them wait until the flower stems and leaves have turned brown and break off when touched. The bulbs can then be dug up (around July) and their offsets removed. After they have been cleaned of soil, leave in a cool light place until they can be planted again in September. Only replant bulbs that look healthy and of a good size.
All members of the Allium family are disliked by many insects and animals. They can be used to protect valuable planting areas against mice, moles, slugs and snails, Even dogs take no interest in the flower beds that they inhabit.
Allium sphaerocephalon is a hardy perennial bulbous plant found in the wild across all parts of Europe except in the northernmost countries (Ireland, Netherlands, Scandinavia, and the Baltic States). Its native range extends to northern Africa and to western Asia as far east as Iran.
Four subspecies of Allium sphaerocephalon are recognised. White-flowered plants from Mediterranean islands and the Balkans with smooth flowers belong to subsp. arvense, while those from Greece and south-west Turkey with papillose flowers (with a roughened surface) belong to subsp. trachypus. Allium sphaerocephalon subsp. laxiflora is restricted to Sicily.
Bulbil-bearing forms belong to subsp. sphaerocephalon, and are sometimes referred to as var. bulbilliferum. Most individuals belong to subspecies sphaerocephalon.
The genus name Allium is the Latin word for garlic.
The species name refers to this species having a spherical flower head. It derives from the Greek words sphaira, meaning 'spherical' or 'globe shaped' and kephale meaning 'head'
Allium sphaerocephalon is popularly known as the drumstick allium and also the round-headed garlic, ball-head onion, and other variations on these names. A reference to the small, egg-shaped heads of flowers that appear in July and August at the tops of long slender stems.
The orthographic variant A. sphaerocephalum is also found.
- Additional Information
Packet Size 50mg Average Seed Count 50 seeds Family Alliaceae Genus Allium Species sphaerocephalon Synonym Syn: Allium sphaerocephalum Common Name Drumstick allium Other Common Names Round-headed garlic, Ball-head onion Other Language Names GR: Kugellauch Hardiness Bulbous Perennial Flowers Late Spring to Early Summer Height 60 to 90cm (24 to 36in) Spread 30 to 38cm (12 to 15in) Position Full Sun to Partial Shade Germination 30 - 365 days