Cosmos atrosanguineus

Chocolate Cosmos (Cosmos atrosanguineus) is a distinctive tuberous perennial prized as much for its rich colour as for its unique fragrance. From July until the first frost, its velvety deep burgundy-brown flowers release a delicate chocolate-like scent that is especially noticeable on warm, sunny days. Its finely divided dark green foliage forms an airy mound that beautifully highlights the dramatic blooms. Growing 50 to 70 cm (20 to 28 in) tall, this elegant plant adds sophistication and charm to summer gardens. Not hardy in Quebec, the tubers must be overwintered in a frost-free location.

Plant the tuber in spring after all danger of frost has passed, 5 to 8 cm (2 to 3 in) deep in rich, fertile, light, and well-drained soil. Choose a warm, sheltered location in full sun and space plants 30 to 40 cm (12 to 16 in) apart. Water lightly after planting, then keep the soil evenly moist while allowing the surface to dry slightly between waterings. Apply a balanced fertilizer every three weeks to encourage abundant flowering without promoting excessive foliage growth. Remove spent blooms regularly and lift the tubers before the first frost.

Chocolate Cosmos is ideal for sunny flower beds, fragrant borders, large containers at least 30 cm (12 in) in diameter, and cutting gardens. Pair it with salvias, verbenas, gauras, coneflowers, or ornamental grasses to create natural-looking plantings with striking texture and contrast. The dark blooms have good vase life and add a refined touch to summer bouquets, while their long flowering season attracts a variety of pollinators. The petals may occasionally be used as a decorative garnish for desserts or specialty coffees, although the plant is grown primarily for its ornamental beauty and distinctive chocolate fragrance.