The genus Allium contains bulbous perennial herbs, commonly called ornamental onions, grown for their spectacular pom-pom flower heads that bloom in spring to high summer, depending on the variety. Allium is an old-fashioned plant with a decidedly modern appeal. Easy-care, this long-blooming ornamental adds architectural interest, and a touch of whimsy, to landscapes with bold, usually bulbous, multi-flowered heads atop long, naked stems. Extremely decorative, the flower heads are typically shades of purple and/or white and range in size, with some reaching 10 to 12 inches in diameter. They make excellent cut flowers, fresh and dried.
Allium is a genus of approximately 700 hundred species, some of which are native to dry, mountainous regions in North America. Only a few are used in landscapes ornamentally, such as the popular A. nutans (Siberian chives, blue chives), A. amplectens (narrowleaf onion), and A. caeruleum (blue globe onion). The plants range in size, usually from 1 to 3 feet tall and 2 feet wide. They love full sun locations with 6 or more hours of direct sunlight but will grow in partial shade with 2 to 6 hours of direct sunlight. The plants are drought resistant (in fact, good drainage is a must); however, they require some moisture when blooming. Alliums make a stunning focal point when mass planted in the landscape, with some species naturalizing easily, but they are also perfect additions to mixed beds and borders. They grow well in containers and are beneficial to the vegetable garden, as they attract desirable insects, bees, butterflies, and hummingbirds and deter deer, rabbits, and other nibbling creatures.