Cosmos

Asteraceae (Compositae)
Annuals, Perennials, Flowers

Native to tropical America, mostly Mexico. Showy summer- and fall-blooming plants, open and branching in habit, with bright green divided leaves and daisylike flowers in many colors and forms (single, double, crested, and frilled). Heights vary from 2 1/2 to 8 ft.

Use for mass color in borders or background, or as filler among shrubs. Useful in arrangements if flowers are cut just after they open and placed immediately in deep, cool water. Sow seeds in open ground where plants are to grow or set out transplants from spring to summer. Plant in not-too-rich soil. Plants self-sow freely and are attractive to birds.

Cosmos atrosanguineus

Perennial from tuberous roots. Grows as a perennial in Zones 4–9, 14–24. Where winters are cold, dig and store as for dahlias. To 2–2 1/2 ft. tall, 1 1/2 ft. wide, with coarsely cut foliage.

Blooms in late summer and fall, with deep brownish red, nearly 2-in.-wide flowers with a strong perfume of chocolate (some people detect a hint of vanilla as well). Attractive companion for silvery-foliaged plants.

Provide well-drained soil. Winter mulch is prudent in all but mildest regions (where plant tends to be rather short lived).

Cosmos bipinnatus

Heights up to 8 ft., widths to 1 1/2 –2 1/2 ft. Blossoms are 3–4 in. wide, with tufted yellow centers and rays in white and shades of pink, rose, lavender, purple, or crimson.

Cosmos sulphureus

To 7 ft. tall, 1 1/2–2 1/2 ft. wide, with yellow-centered,yellow or orange-yellow single flowers. Tends to become weedy-looking at end of season. Two 3–4-ft.-tall,semidouble-flowering strainsare Bright Lights, with 3 1/2-in.flowers in yellow, gold, orange,and orange-red; and Klondike,with 2-in. flowers ranging fromscarlet-orange to yellow. DwarfKlondike or sunny strain is 1 1/2 ft. tall, bears 1 1/2-in. flowers. Foot-tall semidouble bloomersinclude Ladybird mix, with 2 1/2-in. scarlet, yellow, and orange flowers; and ‘Sunny Red’, with orange-red blooms. ‘Yellow Garden’ grows 3 ft. tall and wide, bears light yellow blooms with white center and edge.