Chinese Milkvetch

Astragalus membranaceus

This plant is widely (and apparently safely) used in Chinese medicine, but is related to many species from N. America, including Missouri milkvetch (A. missouriensis) and woolly loco (A. mollissimus), which are known to have poisonous effects on livestock.

Family:  Fabceae
Life cycle:  Herbaceous perennial, zone 5-11
Native:  Northeastern China.
Height:  3 to 4 feet, will sprawl as it matures.
Sun:  Partial shade to full sun
Soil:  Well worked, sandy, dry to moist soil.
Water:  Moderate, will not do well in poorly drained soil.
Flowers:  Pale yellow, blooms from midsummer until frost.
Propagation:  Stratify seed for at least 3 weeks before sowing, then scarify and soak in warm water for 1 hour before planting seed.  Sow directly in field or start indoors and transplant out after last frost date.   Susceptible to transplant shock.   Plant 15 inches apart and water moderately. 
Harvesting:  The roots are harvested in the fall after at least 2 years growth.  Harvest between the third and fifth year depending on your location and how fast the plants grow.  Dig roots using a needle-nose spade or a garden fork to extract all of the root.  Appears to be a tap root with branches.  Could be partially mechanized.
Parts used:  Roots, fresh or dried.
Used as:  Medicinal food, tonic, decoction, traditional tincture, syrup, elixir, lozenge, honey and powder.
Medicinal Benefits:  Immune system stimulant; also an antioxidant, with demonstrated antiviral activity, cardiovascular effects, and immuno-modulating effects.
Market potential:  High, used in many Western and Chinese herbal formulations. Profits and volume up.  Prices range from $7.50/lb to $56.00/lb.  Often sold as ground dried root, or root slices.

KSU Field Trial Data - 2000-2002.

Summary of Field Trial Data: This is a pleasant looking, if sprawling leguminous plant, that could work in the back row of a perennial flower bed, as well as a field crop.  Though we had high hopes for this crop, the root yields in year 3 are not large.  Potential demand is still high however, as this is a very widely used herb with many properties.  Digging and drying the root can be a lot of work, but mechanization may be possible.  The plant does not appear to have many insect or disease pests, but appears to like a well-drained soil, and needs a bit of coddling during the first couple of months after transplanting, as it grows slowly the first year.  It may not work as a direct seeded crop, due to the stratification and scarification required to get good seed germination.  This is a fairly competitive crop, once it gets established, but the percent survival in the second and third years was below 50%, so once might want to start out with a higher planting density initially.  Some of the native Astragalus species in the Great Plains may also have potential as medicinal plants, but medical research has not addressed this question yet.