Black Cohosh (actaea racemosa)

Native Americans called this plant “black cohosh” because of the dark color of its roots; “squaw root” describes its traditional use as an aid in childbirth and as a treatment for women’s menopausal and premenstrual symptoms. A member of the buttercup family, black cohosh is native to eastern North America and is one of about 8 Actaea species that grow in North America. Another 13 species grow in Asia and Europe.

In the 19th century, black cohosh was a widely promoted herbal remedy and a favorite of Dr. John King (1813–1893), a professor of obstetrics at the Eclectic Medical College in Cincinnati, Ohio. King prescribed it for the treatment of nervous disorders, menstrual irregularities, and menopause. Although the herb fell out of favor with the American medical establishment in the early 20th century, the herb’s popularity grew in Europe as German researchers remained interested in its use for treating menopausal symptoms. In recent years, black cohosh has regained popularity in the United States.

Black Cohosh

Plant profile

Common Names: Black Bugbane, Black Cohosh, Black Snakeroot, Rheumatism Weed, Squaw Root

Description: Grows 4 to 7 feet tall; small, creamy flowers on tall, branching spikes; broad, ovate leaves up to 2 feet long, divided into three-lobed leaflets with toothed margins

Hardiness: To Zone 3

Family: Ranunculaceae

Flowering: Early summer to midsummer

Parts Used: Roots

Range/Habitat: Eastern North America; woodlands

Medicinal use

The roots and rhizomes of black cohosh have historically been used for their mild sedative and anti-inflammatory properties. It can be used to treat the pain of arthritis. The herb is best known, however, as a treatment for menopausal symptoms, especially hot flashes and night sweats. It is also used to treat conditions associated with menopause, such as insomnia, nervousness, tension, and depression. The plant contains triterpene glycosides, which may be responsible for its activity. Recent large-scale clinical trials have raised questions concerning the efficacy of this herb for the treatment of certain menopausal symptoms, but other studies are ongoing.

Caution: This herb should not be taken by pregnant women.

Ornamental use

The tall, majestic spires of black cohosh add vertical interest to woodland gardens and contrast with lower-growing, rounded plants such as cranesbills (Geranium spp.) in borders.

How to grow it

Black cohosh grows in moist, humus-rich soil in sun or partial shade. In warmer regions, choose a site with consistent moisture and shade from afternoon sun to keep the foliage from browning. Plant root divisions at any time during the growing season, or sow fresh seed outdoors in fall. The plants grow slowly. Harvest the roots of mature plants in fall, when bioactive compounds are at their highest levels. Divide and replant the remainder of the roots, leaving at least one bud per division.