Black Cosmos (Chocolate Cosmos)
Cosmos atrosanguineus. ASTERACEAE (COMPOSITAE).
Planting and Growing Black Cosmos
You’ll find everything you need to know to plant and grow black cosmos in the accompanying table’s tabs:
-
- Flowers, foliage, and root structure of black cosmos
- Plant hardiness and growing conditions for black cosmos
- Season of bloom and planting time for black cosmos
- When, how deep, and where to plant black cosmos
- How to plant black cosmos
- Watering, fertilizing, care, and pests or diseases of black cosmos
- Landscape and container uses of black cosmos
- Comments about black cosmos and its features
Growing Black Cosmos
Several cultivars of branching, upright, tuberous, deciduous perennial herbs, 2–8 ft. (60240 cm) tall. Opposite, bright green leaves, to 6 in. (15 cm) long, finely cut into 5–7 threadlike segments.
See also Cosmos, Cosmos bipinnatus and Yellow Cosmos, Cosmos sulphureus, two closely related annual plants with similar care needs.
Planting and Care Guide
Blooms
Many brown, chocolate, brownish red, daisylike, fragrant flowers, to 2 in. (50 mm) wide, with yellow centers, on wiry, terminal stems, in summer–autumn. Unique chocolate, vanilla-like scent.
Best Climates
Semi-hardy. Plant as annual bulb, zones 4–6; ground hardy, zones 7–10.
Soil Type and Fertility
Damp, well-drained, sandy soil. Fertility: Rich. 5.0–8.0 pH.
Where and How to Plant
Spring in full sun, 18 in. (45 cm) apart, after soil warms.
Proper Care
Easy. Keep moist; allow soil surface to dry between waterings. Drought tolerant when established. Fertilize annually during active growth. Mulch. Deadhead spent flowers. Propagate by cuttings, division, seed.
Lift and store in cold-winter climates as one would for Dahlia species (see: Curing and Storing Bulbs).
About This Plant
Good choice for accents, backgrounds, containers, foregrounds in cottage, formal, woodland gardens. Good for cutting. Aphid, red spider mite susceptible.