They may be related to the humble onion and pungent garlic, but alliums - ornamental onions - make delightful additions to the flower garden.
They are one of my favorite bulbs. Flowering from May through July, ornamental onions add a touch of stylish whimsy to your garden.
Most types bloom in late spring to early summer and have fuzzy rounded flowers that look like lollipops atop slender stalks.
Of the several hundred species of alliums known, only a few are widely planted in gardens, but these all mix beautifully with garden perennials.
Good companions include pink or purple-flowering perennials such as iris, lavender, salvia, peony, hardy geranium and ornamental grasses such as blue oat grass, blue fescue and fountain grass.
All ornamental onions thrive in well-drained soil in full sun or light shade. They need to be planted in the fall, along with other spring-flowering bulbs.
When planting, place bulbs at a depth twice their own diameter. They will come back year after year to form gorgeous big clumps of flowers.
Allium aflatunense (also known as Allium hollandicum): Native to Iran. Dense spherical umbels of starry lilac-purple flowers in May on stems two to three feet tall. For maximum effect, plant in clusters of 10 bulbs or more.
Two favorite cultivars are the dark lilac 'Lucy Ball' (named for the late entertainer Lucille Ball), and the violet-purple 'Purple Sensation' (above). Both grow about three feet tall, and make good cut flowers.
A. christophii, also known as A. albopilosum: Native to Turkestan and commonly known as Star of Persia, this allium produces huge 10-inch flower heads of shiny star-shaped silvery, amethyst colored florets on two-foot stems in mid-June.
A. giganteum: Native to Siberia and Himalayas, this ornamental onion is as stunning as its name suggests. 'Globemaster' is a show-stopping cultivar with enormous eight to 10-inch puffballs of purple-mauve florets atop four-foot stems in late June into July. Plant it in groups of three or more in borders.
A. karataviense: Native to Turkestan and noted for its low-growing profile, this allium has fuzzy-looking beige-pink flowers in an umbel up to 12 inches across on stiff eight-inch stems. The leaves are spotted grey-purple.
A. karataviense 'Ivory Queen' is a selection with two to three inch flower heads of clear ivory, rather than the usual faint pink. This flower shines above broad, blue-colored leaves.
A. sphaerocephalon: Native to southern Europe and Asia Minor, this one has compact purple flowers atop two-foot tall stems in July. The tight flowerhead earns it the common name of drumstick allium.
This allium is quite inexpensive, widely available and easy to grow, so you can afford to plant them generously. It's also excellent for cutting. I like it interplanted with fountain grass (Pennisetum alopecuroides) and purple coneflower (Echinacea cultivars).
![]() |
Ornamental onions make good cut flowers. They give off a bit of an onion scent if the leaves or stems get slightly bruised, but the odour goes away after the stems are immersed in water.
Dried flower arrangers love the medium and tall species, which dry superbly and can be spray-painted purple, gold or copper to star in dramatic arrangements.
How to plant spring-flowering bulbs
Tulips with staying power