Black cosmos (Cosmos atrosanguineus)

Black cosmos

Cosmos atrosanguineus is a herbaceous perennial plant growing to 40 to 60 cm tall, with a fleshy tuberous root. The leaves are 7 to 15 cm long, pinnate, with leaflets 2 to 5 cm long. The flowers are produced in a capitulum 3 to 4.5 cm diameter, dark red to maroon-dark brown, with a ring of six to ten (usually eight) broad ray florets and a center of disc florets;

Scientific classification

Species

Black cosmos (Cosmos atrosanguineus)

Asters bellflowers fanflowers and allies

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Perennial

Lifespan

Herb

Plant Type

Late spring, Summer, Fall

Bloom Time

45 cm

Plant Height

30 cm

Spread

Green

Leaf Color

Red

Flower Color

Green, Red

Stem Color

Images of Black cosmos

Distribution of Black cosmos

Distribution Map

Black cosmos is naturally found in the warmer regions of North America but is widely cultivated in temperate zones across various continents. It thrives in a range of garden settings beyond its native range, enjoying popularity among gardeners and horticulturists for its striking appearance.

Native

Cultivated

Invasive

Introduced

No species reported

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Hemisphere Trend Curve

Northern

Sorthern

Care Guide for Black cosmos

Every week

Water

Full sun

Sunlight

5 - 32 ℃

Ideal Temperature

Garden Soil

Soil Type

Water: Black cosmos thrives in moderate climates with consistent moisture, preferring regular hydration without waterlogging. Watering weekly maintains its vigor. As an herbaceous perennial with dark, velvety flowers, black cosmos is mainly grown outdoors to enjoy the full growing season and ample rainfall.

Fertilize: For black cosmos, regular fertilization with balanced nutrients is crucial. Apply monthly during the growing season using diluted liquid fertilizer while avoiding over-fertilization. Water soil before application and adjust feeding in cooler months to ensure black cosmos thrives, yielding a stunning dark-hued display.

Pruning: Black cosmos features dark, velvety flowers and thrives with early to late spring pruning. Removing spent blooms and dead stems encourages flowering while maintaining health. Thinning overcrowded branches improves air circulation, reducing disease risk. Proper pruning enhances vigorous blooms and overall vitality in black cosmos.

Propagation: Black cosmos features dark-hued flowers, ideal for adding drama to gardens. Propagate via division in spring, ensuring each tuber has a growth bud. Plant divisions at the same depth, water thoroughly, and with care, black cosmos will flourish, producing its signature chocolate-scented blooms.

Repotting: The chocolate-scented black cosmos thrives when repotted every 2-3 years in spring, ideally in a slightly larger container with well-draining soil. It requires consistent moisture without waterlogging, a sunny spot, and regular deadheading to promote blooming.

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