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Cimicifuga racemosa
black bugbane
Eastern North America (Ontario to Georgia, west to Missouri)Learn more
Overview
A clump-forming perennial of eastern North America in the family Ranunculaceae. Plants form basal mounds of large, compound leaves 24–36 inches (60–90 cm) tall, with leaves 2–3 times ternate and leaflets 2–4 inches (5–10 cm) long, coarsely toothed, dark green. In midsummer, tall, unbranched to lightly branched flowering scapes rise 4–8 feet (120–240 cm), bearing slender racemes 12–24 inches (30–60 cm) long of small, white flowers without petals; the white color comes from numerous stamens. Flowers have a musky, slightly unpleasant odor. Flowering stems may require staking in exposed positions. After bloom, green fruit capsules develop and ripen to black in fall — the source of the common name black cohosh. Spreads slowly by rhizomes; does not self-seed aggressively. Grows best in consistently moist, woodland conditions; declines in hot, dry summers.
Native Range
Native to eastern North America, from southern Ontario and New England south through the Appalachian Mountains to Georgia and Tennessee, and west to Missouri and Arkansas. Grows in moist, rich deciduous woodlands, ravines, and stream banks, typically in partial to deep shade at 500–5,000 feet (150–1,500 m) elevation.Suggested Uses
Commonly planted in shaded woodland borders and naturalized woodland gardens at 24–36 inch (60–90 cm) spacing. Tall flowering stems provide vertical accent in shade gardens where few plants reach this height. Not suited to dry shade or full sun; requires reliable moisture to perform well.How to Identify
Appearance
Size & Dimensions
Height4' - 8'
Width/Spread2' - 3'
Bloom Information
Blooms July through August in zones 3–7, with bloom in mid-July being typical in zone 6. In zone 3, bloom may not begin until early August. Individual racemes remain open for 2–3 weeks; the total bloom period is approximately 3–4 weeks. Bloom timing shifts 1–2 weeks later with each zone northward.Detailed Descriptions
Flower Description
white (petal-less, composed of stamens)Foliage Description
dark greenGrowing Conditions
Sun Requirements
Requires 2-4 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
Care & Maintenance
Care Guide
Plant in partial to full shade in moist, humus-rich, slightly acidic soil with a pH of 4.5–6.0. Consistent moisture is important; foliage wilts and plant vigor declines significantly in dry soils. Amend planting site with compost or aged leaf mold to improve moisture retention. Mulch 2–3 inches (5–8 cm) deep. Fertilize lightly in spring with a balanced slow-release fertilizer. Division is rarely needed; established clumps are long-lived and slow to establish after disturbance. Stake flowering stems in exposed, wind-prone locations. Deer typically avoid this plant due to its odor.Pruning
Cut flowering stems to the base after bloom and fruit set, or leave fruit capsules through fall for late-season interest. Cut all foliage to ground level in late fall after frost or in early spring before new growth emerges. Division is infrequent; disturb clumps as little as possible as plants are slow to re-establish after root disturbance.Pruning Schedule
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fallearly spring