Astragalus

A perennial legume one to three feet tall with feathery leaves of many small paired leaflets, loose spikes of pale yellow pea flowers, and papery pods. The taproot is long, fibrous, and tough, with a yellowish core.

It is sold as long, thin, tongue-shaped slices with a pale cream to yellow cut face, fibrous and slightly sweet, with a faint beany taste.

The Shennong Bencao Jing lists astragalus among its highest grade of herbs. Its name is often read as “yellow leader,” the chief of the tonics.

The Yuan dynasty “jade windscreen” powder (yù píng fēng sǎn), astragalus with atractylodes and saposhnikovia, was given to people who caught one cold after another. Li Dongyuan’s 1247 “Dang Gui Blood-Tonifying Decoction” is just astragalus and dang gui in a five-to-one ratio.

Astragalus likes full sun and deep, sandy, well-drained soil, and dislikes wet feet, so it suits dry Western gardens. Scratch or nick the hard seed and soak it overnight before sowing. Roots are ready after two to four years.

The medicinal root comes from A. mongholicus (long sold as A. membranaceus). There are about 3,000 other Astragalus species, and many North American ones are toxic.

In the soup pot it is paired with dang gui, goji, jujube, and ginger.

Dig roots in autumn, cut off the crown and fine rootlets, and dry them in the sun until firm. They are sliced lengthwise at an angle while still slightly flexible.

A handful of slices in the stockpot through the winter is the most common household use in China and Taiwan, especially for people who tire easily or catch every cold.

Simmer 15 to 30 grams of slices (a small handful) in two to three quarts of soup or broth for an hour or more, then remove them; they are too fibrous to eat. The taste is mild, sweet, and a little earthy. See the <a href="/recipes#recipe-astragalus-dang-gui-chicken-soup">astragalus and dang gui chicken soup</a>.

Root as decoction, soup, powder, and syrup. In Chinese medicine it is the main herb for “tonifying qi” and “securing the exterior”: for fatigue, poor appetite, frequent colds, sweating easily, slow-healing sores, and swelling.

In the classical recovery formulas described in Walker and Bauer’s The Ancient Art of Life and Death (2002), such as the Restore the Spleen decoction (guī pí tāng), astragalus builds energy alongside ginseng or codonopsis.

Chinese medicine: sweet, slightly warm, entering the Spleen and Lung channels; a qi tonic.

The root contains polysaccharides, saponins such as astragaloside IV, and isoflavonoids including calycosin and formononetin, along with amino acids and trace minerals.

NCCIH says there isn’t enough reliable evidence to know whether astragalus helps any condition, though recent reviews of mostly Chinese studies point to possible effects on immune function, blood sugar with metformin, and some kidney diseases. Doses up to 60 grams a day for four months have not caused problems in studies.

People with autoimmune diseases are advised to avoid astragalus, and it may interact with drugs that suppress the immune system, such as those taken after an organ transplant. Animal research raises concern about use in pregnancy. Chinese practice avoids it at the start of a feverish cold.

Never gather wild milkvetch or locoweed in the American West. Many of these Astragalus species poison livestock with swainsonine or build up toxic selenium, and several grow wild in Arizona.