BULB WATCH 3: ALLIUM

ALLIUM is the proper name for the ornamental garlic. Do people avoid growing these bulbs because they think their garden will smell more like a bistro than a flower bower? The British garlics - A. triquetrum, which is naturalised in woods and A. ursinum, which grows by streams - are very invasive. They do smell strongly, especially if you walk on them, but I have never noticed so much as a passing whiff from the ornamental forms. Occasionally when handling the bulbs you are aware of garlic, but not overwhelmingly so.

All garden alliums do best in good drainage and a sunny place. On clay soils they are almost impossible to keep from year to year, but in sandy or stony conditions they will seed and increase. The large summer flowering forms tend to have long stems with a ball of flowers at the top. The foliage dies unattractively, leaving a bare stem, so they should be planted behind something to hide their lower parts. The seedheads, the sort of thing to make a flower-arranger swoon, are lovely for months. Ultimately they do go brown, but even then they are airy looking - not a ball of solid death like opium poppy seeds - so they can be left until they collapse gracefully. By which time, if you are lucky, they will have seeded themselves everywhere.

A. afflatuense is May-flowering, almost a metre high and easy to grow if conditions are right. Its flowers can be a washy mauve unless you specify the named form, "Purple Sensation". Here in my garden it is a lovely consolation for lack of tulips: the mice have no appetite for garlic. A. giganteum is slightly taller and has a larger head, but I think the colour is less good. It is also hard to avoid the large leaves looking messy when cover is scarce among perennials. I have tried giganteum among sage and chicory in the herb garden, but the sage is too young and the chicory too slow to make its summer growth in time to hide the garlic's awkward die-back.

A. albopilosum (or christophii) has a huge head - a sort of Queen Mother's hat, a tulle-spangled confection - on quite short stems of around 1ft. It is a glamorous flower, but expensive. At twice the price of A. afflatuense you need to be sure you can keep alliums happy before investing in albopilosum. A. siculum, which is now more properly known as Nectaroscordum siculum, is a tall, green-flowered garlic. It has curious, almost sinister, green bells tinged with purple. This year I saw it growing in long grass and light shade, which looked very effective. N.bulgaricum lacks the purple passages of N. siculum but is just as beguiling if you like weird flowers. Both of them can manage some shade, and they do not, as other garlics do, like very dry soil.

A. roseum is blandly pretty. Its clusters of pink flowers in May are quite large and at 112ft it is not hard to find a companion to make up for its lack of substance below the flower. It's is a terrific seeder, but there is no harm in that, as there is always room for another slender stem.

Later in the summer, A. caeruleum is a real blue garlic on 2ft stems. Its flowerheads are no more than 2in across, but the colour is so intense that in a dry sunny place it looks terrific. A. sphaerocephalon is a darker, cone-shaped garlic which is one of the latest to flower.

In this most difficult of summers, alliums, unlike other flowers, have lasted for more than a day. In well-drained sunny gardens they are always rewarding, but like their onion relations they do even better when well fed. Rich, well-drained soils will grow the best alliums of all.

SUPPLIERS: Jacques Amand Ltd, The Nurseries, 145 Clamp Hill, Stanmore, Middlesex HA7 3JS (0181-954 81380)

Mary Keen