Allium tuberosum is a late-season bloomer from the onion family. Native to southeastern Asia, it is known by several common names including garlic chives, Chinese chives or Chinese leek. It is sometimes confused with a very similar species, A. ramosum or fragrant-flowered garlic, but that plant blooms earlier in the year and has a slightly different leaf structure. Although A. tuberosum is typically used as an ornamental in North America, it is edible and has been used in Chinese herbal medicine for a variety of ailments.
This herbaceous perennial, hardy in zones 3-9, forms slowly expanding clumps of gray-green foliage 10-20″ tall. Each elongate, poorly developed bulb is attached individually to a stout rhizome similar to that of an iris, and produces 4-9 leaves. The narrow, flattened, strap- or grass-like leaves arch downward at the tips, forming a fountain of green that remains tidy and attractive throughout the growing season. When bruised or crushed, the leaves (and other plant parts) have a strong onion or garlic scent. In warmer climates the plants are evergreen but in colder climates they die back to the ground over the winter. Just like chives, cutting the leaves back encourages new growth. Leaves can be harvested to eat anytime they are green.
In late summer to early fall, flowers open on sturdy, two to three foot-tall stalks well above the foliage. Each 2-3″ wide loose umbel contains many small, white, star-shaped flowers with brown-striped tepals. The flowers are attractive to butterflies, bees and other pollinators, with a sweet scent. They are good for cutting and the seed heads for dried arrangements.
Eventually the flowers are followed by dark, papery capsules filled with hard, triangular-shaped black seeds. Because it self seeds very readily and produces seed prolifically (like many ornamental onions), it is best to cut off the flower stalks as soon as they have finished blooming to prevent rampant spread.
Even though it can spread aggressively by seed, the seedlings are relatively easy to remove when young (although they can be quite numerous, so weeding may take a lot of time). This plant can be invasive under some conditions, so should be planted with care.
Grow garlic chives in full sun in well-drained soil. It can easily be started from seed, or from divisions. Once established, A. tuberosum is very heat, cold and drought tolerant. Clumps should be lifted and divided about every 3 years to maintain vigor and blooming.
Garlic chives combine well with many perennials and annuals. The grayish leaves soften bright oranges and set off pink or rose-colored flowers. They are a nice contrast to purple foliage, such as dark-leaved sedums or heucheras. Plants can be used as low-maintenance edging or in containers to provide vertical interest when in flower. Potted plants can be brought inside over the winter for a supply of leaves for cooking.
The flavor of the leaves of A. tuberosum is subtle, like very mild garlic, while the narrow bulbs are strong and sharp when eaten raw. The leaves are used similarly to the way chives or green onions are used. They can be added to salads, egg dishes, soups, or stews. It is used in stir fries and other dishes in several oriental cuisines, especially Korean. The flowers are also edible, so can be used as a garnish or added to salads.
– Susan Mahr, University of Wisconsin – Madison