Introduced to the US as an ornamental flowering plant from Mexico or tropical America, tall Cosmos offers a variety of daisy-like maroon, pink, lavender, and white flowers on stalks that will get up to 4 feet tall. The specific epithet refers to the plant's bipinnate leaves Plant cosmos in a location that receives at least a half-day of direct sunlight. Sow the seeds outdoors after the danger of frost is past and when the soil has warmed to at least 65 degrees. Rake seeds into a loose soil as planting seeds too deeply will hinder germination. Keep the soil moist for 5 to 10 days after seeding. Seeds will germinate in 7 to 21 days. Cosmos needs only basic care to provide an abundance of colorful blooms all summer. Taller varieties may need staking if subjected to high winds and frequent storms. Deadheading will promote further blooms. The plants will readily reseed. The summer flowers consist of pastel colors of ray florets surrounding a center of disc florets. The leaves are deeply cut and lacy. Use these plants to add summer color to the border of cottage, cutting and butterfly gardens. Insects, Diseases, and Other Plant Problems: Stem canker, powdery mildew, and gray mold are common issues. Insects include aphids, Aster Leafhopper and the Gray Looper Moth. More information on Cosmos .
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.
Full sun (6 or more hours of direct sunlight a day) | Partial Shade (Direct sunlight only part of the day, 2-6 hours)
Soil texture
Clay; Loam (Silt); Sand
Soil pH
Alkaline (>8.0); Neutral (6.0-8.0)
Soil drainage
Good Drainage | Occasionally Dry
Available space
12 inches-3 feet
NC region
Coastal; Mountains; Piedmont
Mature size
Height: 2 ft. 0 in. - 4 ft. 0 in. | Width: 2 ft. 0 in. - 3 ft. 0 in.
Growth rate
Rapid
Maintenance
Low
Canopy layer
4 - Herbaceous (3-15 ft)
Form & Appearance
Habit / form
Clumping; Erect
Texture
Medium
Leaf color
Green
Leaf type
Compound (Pinnately , Bipinnately, Palmately)
Leaf arrangement
Opposite
Leaf shape
Pinnatisect
Leaf margin
Entire
Leaf value
Showy
Leaf size
3-6 inches long, 1-3 inches wide
Hairs present
No
Leaf detail
The lacy, thread-like leaves are deeply cut. They have a fine texture.
Flower color
Gold/Yellow; Pink; Purple/Lavender; White
Flower value
Good Cut; Long Bloom Season; Long-lasting; Showy
Flower form
Head
Flower shape
Radial
Flower size
1-3 inches
Flower detail
2-4-inch saucer-shaped daisy-like blooms are available in a variety of colors and bloom all season. The ray florets surround the center of disc florets.
Bloom time
Fall; Spring; Summer
Fruit type
Capsule
Stem color
Green; Red/Burgundy
Stem detail
Unbranched along the erect to ascending stem.
Wildlife & Ecology
Native status
Native
Origin
Mexico and southwest North America
Wildlife value
Attracts pollinators, birds and butterflies.
Attracts
Bees; Butterflies; Pollinators
Play value
Attractive Flowers; Attracts Pollinators; Colorful; Easy to Grow