Cosmos bipinnatus
Common Name: cosmos
Type: Annual
Family: Asteraceae
Native Range: Mexico, southern United States
Zone: 2 to 11
Height: 1.00 to 4.00 feet
Spread: 2.00 to 3.00 feet
Bloom Time: June to frost
Bloom Description: Red, pink or white rays and yellow center
Sun: Full sun
Water: Medium
Maintenance: Low
Suggested Use: Annual, Naturalize
Flower: Showy
Attracts: Butterflies

Culture

Warm weather annual that is easily grown in average, well-drained soils in full sun. Appreciates even moisture, but tolerates some dry soils. Avoid rich, fertile soils. Sow seeds outdoors just before last spring frost date or start seeds indoors 6-8 weeks before last spring frost date. Shelter plantings from strong winds. Space taller plants close together for support. Deadhead spent flowers to prolong bloom, but leave enough flowerheads for self seeding.

Noteworthy Characteristics

Cosmos bipinnatus, commonly just called cosmos, is native to Mexico. It is a popular, low-maintenance, late-blooming, showy annual that typically grows 2-4’ tall on erect stems clad with pinnatisect, medium green leaves that are deeply cut into threadlike segments. Single, saucer-shaped, daisy-like flowers (to 2-4” diameter) with red, pink or white rays and yellow centers bloom freely from early summer to frost. In hot and humid summer climates, plants may slow down considerably in late summer. Plants have escaped gardens and naturalized, particularly along roadsides, fields and waste areas, in many parts of the U. S. Cultivars feature single, semi-double or double flowers in a larger variety of colors including white and bicolor on plants ranging in height from dwarf to tall.

Genus name comes from the Greek word kosmos meaning beautiful.

Specific epithet refers to the plants bipinnate leaves.

Problems

No serious insect or disease problems.

Garden Uses

Mixed beds and borders. Cutting gardens. Cottage gardens and wild gardens.