University of Illinois Extension

Appealing Alliums

From flavorful vegetables to eye-popping ornamentals, alliums add punch to the garden –and the dinner table, said a University of Illinois Extension horticulture educator.

“Onions, shallots, leeks, garlic and chives are all alliums that lend savory flavor and aroma to soups, salads, and dishes enjoyed around our planet,” said Nancy Pollard. “Chicago, the Midwest’s largest city, is named for a flavorful native allium. It is thought by many to be a prairie plant, the nodding wild onion (Allium cernuum).

“However, findings published in 1991, favor a wild leek (A. tricoccum) that inhabits woodlands. The Native American tribes called the plant in question shikaakwa or chicagoua. Let the botanical historians sort it out, while we gardeners enjoy alliums of many kinds, both native and exotic as adornments for our yards and aromatic flavors for our dinner plates.”

For pure drama and delight, Allium giganteum flower heads floating above a perennial border in late May can’t be beat. Hundreds of small star-shaped flowers form a globe attached to a naked stalk that rises about four feet above the ground, she noted. Ornamental alliums are grown for these attractive umbels. (Umbels describe a flower cluster whose individual flower stalks rise from a single point, like an umbrella.)

“Most often the umbels of allium are spherically shaped, but some appear more floppy than others, or are more disk-like,” she said. “They come in showy shades of purple, blue or white, and, less commonly, yellow.

“Alliums grow from bulbs. This storage device allows them to store water from rainy spring weather, and then go dormant during the hot dry summer. If you want a show again in following years, steer clear of overplanting them with annuals. Annuals usually need lots of summer watering. Dormant bulbs planted among annuals usually rot and die.”

Most alliums do best in full sun. However, those native to woodland areas, like wild leeks are adapted to grow quickly in the spring before the trees leaf out and cover them with shade. On some, the leaves die back in summer; others retain their grass like foliage all season. You can find bulbs in the fall in local markets and catalogs.

“Do a little research to determine the needs of the ones you find most appealing,” Pollard recommended.

Pollard also shared some of her favorites:

Stars of Persia (A. christophii or A. albopilosum) – Stems are a stout six inches to 24 inches long depending on variety. Round purple umbels form a seven-inch symmetrical sphere. Dries well for flower arrangements or if left in the garden.

“I’ve known folks to carefully spray paint these with bright colors in place (shielding the other plants), for a whimsical touch all summer long,” she said. “Some have a soft sweet fragrance. Foliage dies back. Needs full sun.”

Chives (A. schoenoprasum) – Narrow, tubular leaves, floral stems, about 12 inches long. Spring blooms are showy round umbels one inch across and vary from pale purple to pink depending on variety. Chives are both edible and decorative. They make a nice border around other plants, forming clumps that will need to be divided in time. Needs full sun to partial shade.

Garlic Chives (A. tubersosum) – Thin strappy leaves; floral stems about 18 to 24 inches long. Summer blooms are a loose, one and one-half inches across, in an upright wide white umbel. Clump forming and needs full sun to partial shade.

Blue Globe Onion (A. caesium) - Strap-like foliage dies back after flowering. Stems up to 24 inches long. Dense blue flowers form a one and three-quarter inch head. Needs full sun to partial shade.

Persian Onion (A. aflatunense ‘Purple Sensation’) - Stems about 30 inches long. Rich violet, tightly packed round four-inch umbels. Blooms in late spring (May-June). Plant among other perennials to hide foliage that dies back. Plant in full sun.

Giant Allium (A. giganteum) – Flower stem between four to six feet tall. Round rosy purple umbels five to 15 inches, symmetrical sphere, zone 4-8. Needs full sun.