In the swirling cosmos of bulbs, alliums are the bright, stately planets of the garden. Alliums are never the first spring-flowering bulbs to bloom, but they are perhaps the season's most formidable flower.
Alliums are the ornamental cousins of onions; their flowers are characteristically clusters of blooms, often forming tight globes, but sometimes arranged in loose bunches of pendant bells, like tassles. Tall alliums, particularly 'Gladiator', which has purple flower-heads the size of a soft-pitch softball and stands every inch of 4 feet tall among the peonies, are not for shy gardeners, but the vast world of alliums also has a demure side.
The variety within the genus allium is astounding: about 700 species are known. Little Allium moly, sometimes called golden garlic, grows to only about a foot tall and produces dancing clusters of bright yellow flowers in early summer. Allium aschersonianum has very dark pink flowerheads about the size of a tennis ball and stands about two feet tall. Allium rosenbachianum, one of the earliest alliums to bloom, has round, five-inch flowerheads of purple, white, or a rich lilac. Even after the blooms fade, most allium flowerheads remain quite showy on their tall wands through early summer.
Allium flowers rarely smell like onions — it's the foliage that smells strong, and only when you crush it. They are all easy to grow; few spring-flowering bulbs are as undemanding as alliums. They bloom profusely in full sun, but tolerate a surprising amount of shade. Alliums can thus be planted to advantage among roses, peonies, hostas, and ferns and under trees and around shrubs. Small alliums make a lacy edge at the front of a border: chives, which are easy to grow from seed, make a perfect edging for an herb garden, and they look pretty in front of roses, in a rock garden, or along the edge of a flower bed, too. The largest alliums are like garden sculptures; they're tall enough to plant at the back of a flower bed, but put a few bulbs up front, too: you'll want to shake them by the stems, pat their fuzzy heads, and inspect their thousands of sparkling flowers up close.