WSU Clark County Extension

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Black Cohosh

Scientific name: Actaea racemosa

Type:Herbaceous perennials
Plant Requirements
Zone:3 to 8
Sun:Partial shade to full shade
Plant Characteristics
Height:6 ft
Width:4 ft
Bloom:Summer flowers
Bloom Time:August to September
Bloom Color:White
Additional Characteristics



Wildlife value

Description Black cohosh adds architectural height and late summer bloom to a shaded part of the border or shade garden. The alternative name of Bugbane refers to the bad odor of this plant, making it repellent to insects. Also commonly classified as Cimicifuga racemosa. More recently, it has been used by modern medicine for symptoms associated with menopause, in particular hot flashes.

This herbaceous perennial grows to 4’-6’ in height and spreads to 2’-4’ in width.

The leaves are astilbe-like, deeply cut and tripinnate. When in the shade the foliage is an attractive deep green. However plants in full sun will take on a much lighter shade of green.

Small, numerous, creamy white, fragrant flowers appear in late summer to early fall in long, terminal racemes resembling fluffy spires (typically 1-2’ long) rising well above the foliage on wiry stems.

Easily grown in average, medium moisture soils in part shade to full shade. Black Cohosh prefers humusy, organically rich, moisture-retentive soils. Foliage tends to scorch and otherwise depreciate if soils are allowed to dry out.

No serious insect or disease problems.
For assistance, contact Dr. Charles Brun (, (360) 397-6060 5701
Computing and Web Resources, PO Box 6234, Washington State University, Pullman WA 99164-6234