Perennials

Actaea racemosa

Black Cohosh

Ranunculaceae

Eastern North America (Ontario and Massachusetts south to Georgia and Tennessee)

At a Glance

TypePerennial
HabitUpright
FoliageDeciduous
Height4–7 feet (1.2–2.1 m)
Width24–36 inches (60–90 cm)
Maturity4 years

Growing Zones

USDA Hardiness Zones

3 - 8
Zone 3
Zone 4
Zone 5
Zone 6
Zone 7
Zone 8
These zones indicate the coldest temperatures this plant can typically survive.
Frost Tolerancehardy

Key Features

Attracts Pollinators
Deer Resistant
Native to North America
Maintenancevery low

Overview

Actaea racemosa is an upright herbaceous perennial reaching 4–7 feet (1.2–2.1 m) tall in flower with a spread of 24–36 inches (60–90 cm), forming a large clump of bold compound foliage. It is the largest native *Actaea* in eastern North America and one of the tallest shade-garden perennials for temperate climates. Leaves are large, two to three times ternately compound, 18–30 inches (45–75 cm) wide overall, with sharply toothed leaflets, medium to dark green. Flowers are tiny, white, with numerous stamens, produced in long wand-like racemes 12–24 inches (30–60 cm) long on arching stems in July through August. The flowers produce a faint, musky odor that attracts flies and beetles for pollination. After bloom, small black to dark brown capsular fruits develop on the raceme. Actaea racemosa was formerly classified as Cimicifuga racemosa; both names appear in the literature. The roots have a long history of use in traditional medicine among eastern North American Indigenous peoples, and the plant remains commercially harvested as a botanical supplement. Not acutely toxic, but ingestion of large quantities of roots or plant material causes GI distress.

Native Range

Actaea racemosa is native to eastern North America, ranging from southern Ontario and Massachusetts south to Georgia and Tennessee, occurring in moist, humus-rich deciduous forest understories, particularly under oaks, maples, and beeches. It grows on slopes and in coves with consistently moist, well-drained soils at elevations from sea level to 4,500 feet (1,370 m).

Suggested Uses

Planted in shaded woodland gardens, native plant borders, and naturalized areas at 24–36 inch (60–90 cm) spacing. The tall white July–August racemes add vertical structure to the shade garden in midsummer. Suited to moist, shaded sites in zones 3–8; particularly appropriate for native woodland gardens in eastern North America. The bold compound foliage provides substantial textural mass through the growing season. Not suited to dry soils, alkaline conditions, or hot sunny sites.

How to Identify

Actaea racemosa is identified in bloom by the tall wand-like white racemes, 12–24 inches (30–60 cm) long, rising 4–7 feet (1.2–2.1 m) above large compound green foliage in July–August. The combination of raceme length, plant height, and large bipinnate-to-tripinnate leaves with sharply toothed leaflets is distinctive among eastern woodland perennials. Distinguished from Actaea simplex cultivars by green (not dark purple or bronze) foliage, earlier bloom (July–August vs. September–October), taller stature, and faint musky rather than sweet fragrance. Distinguished from A. pachypoda by much greater height and wand-form racemes vs. short cylindrical racemes.

Appearance

Size & Dimensions

Height4' - 7'
Width/Spread2' - 3'

Reaches mature size in approximately 4 years

Colors

Flower Colors

white

Foliage Colors

green
dark green

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~4 weeks
J
F
M
A
M
J
J
A
S
O
N
D
Summer
Wand-like white racemes, 12–24 inches (30–60 cm) long, are produced on arching stems in July through August, lasting 3–4 weeks. Individual flowers are small, 0.25 inch (6 mm) wide, with numerous stamens. The flowers produce a faint musky odor. Dark capsular fruits develop on the racemes after bloom.

Detailed Descriptions

Flower Description

white

Foliage Description

medium to dark green

Growing Conditions

Sun Requirements

Partial Shade
Full Shade
Tolerates up to 4 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range4.5 - 7.0(Acidic)
357912
Soil Types
loamclay
Drainage
moist

Water & Climate

Water Needs

Medium

Frost Tolerance

hardy

Time to Maturity

3–4 years

Care & Maintenance

Care Guide

Plant in moist, humus-rich soil with a pH of 4.5–7.0 in partial to full shade. Water consistently — does not tolerate prolonged drought; water weekly during summer dry periods. Mulch annually with leaf litter or shredded bark to maintain humus content and soil moisture. Tolerates more summer shade than most perennials and performs poorly in hot, sunny conditions. Performs in zones 3–8. Large established clumps spread slowly and do not require division for many years. No routine fertilization is required in soils with adequate organic matter.

Pruning

Cut stems to the ground in late fall after frost, or leave standing through winter for structural interest. Remove spent racemes after bloom if desired. Division in early spring is rarely necessary and can be done every 8–10 years if clumps become overcrowded; the thick woody rhizomes can be difficult to divide.

Pruning Schedule

J
F
M
A
M
J
J
A
S
O
N
D
fall

Maintenance Level

very low

⚠️ Toxicity Warning

Toxic to pets and humans