Seattle Area Oriental Medicine and Acupuncture School
 
Sign up for our
quarterly e-news

Acupuncture News - Seattle WA
Articles on AOM
Professional News
Upcoming Classes


Back to herb list

Cong Bai

Botanical name: Allium fistulosum
Common name: Scallion, Spring onion

Family: Liliaceae, lily family
Part used in Chinese medicine:  bulb

Major Chinese medicine actions:
Releases exterior, induces sweating, disperses cold, unblocks yang qi

Cong Bai

Cong Bai

Cong Bai
Photo Credits: (top to bottom)
Photo 1: Allium fistulosum; 06/2008; author C. Micleu; permission Jade Institute
Photo 2: Allium fistulosum; 05/2005; author Radomil; permission under GFDL
Photo 3: Allium fistulosum; 05/2006; author Isaka Yoji (cory); permission under GFDL

Comments:
Allium fistulosum, sometimes called the Welsh onion, is only known in cultivation and dates back to at least 200 B.C. Native to northwest China, it seems to have originated from the wild onion plant, Allium altaicum Pall. that grows in Siberia. The plant has a variety of uses as medicinal herb, culinary onion, planted for termite prevention and juiced for aphid pest control.

Growing and Propagation

The plant is perennial, though grown commercially primarily as an annual or biennial. It does not have a long dormant stage like some onions and will continue its vegetative growth without developing a large bulb if left to grow as a perennial. Allium fistulosum is found extensively in northern China where they use a special cultivation technique. By mounding up the soil around the plant continuously during the growing period, the long white portion of the onion grows up to 12 inches long and 3/4 inch wide. It is this white part of the onion that is used medicinally.

Allium does best grown in well-drained, loamy soil, rich in organic matter. It is somewhat drought tolerant and excessive watering should be avoided as water-logging quickly kills the active roots. The plant prefers full sun, and is quite adaptable to a wide range of climates from the cold winters of Siberia to the hot humid conditions of Central Africa. It is hardy in USDA zones 6 to 10. There are a variety of factors that must occur for flowering to be stimulated. When the days shorten, the temperatures drop below 55 degrees F, and the plant forms a certain number of leaves or a pseudostem of a certain thickness, then flower buds will develop.

Allium may be propagated by seeds sown in containers in the fall. They should be kept in a cold frame until seedlings are large enough to transplant, though it can take over a year for the seeds to germinate. The plant is much easier to cultivate by removing the small offsets of the bulb in the fall and planting them directly in the garden about 2-4 inches deep.

Harvesting and Preparation

For medicinal use, the Allium bulb with rootlets intact is preferred.

 

Back to herb list