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Plants that fill a similar niche:
Verbena canadensis Verbena canadensis
Coreopsis tripteris leaves and flowers
Cosmos Cosmos spp.
Cosmos bipinnatus has some common insect problems:
Aphids Found on Flowers and Foliage

Cosmos bipinnatus

Phonetic Spelling
KAHS-mos bye-pin-NAY-tus
Description

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 word cosmos is derived from the Greek word for harmony, referring to its evenly placed petals.  Although many cultivars and varieties are available, two annual species, Cosmos sulphureus (Yellow Cosmos) and Cosmos bipinnate are the most familiar to the public.

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.

When the spring-planted cosmos appears to have an abundance of dried seed, do not remove the plants. Encourage re-bloom by cutting the plants back to 12 to 18 inches high. They will be back in bloom in a month and the seed that is cut off will fall to the ground, germinate in the hot soil, and increase the density of your plant population and the eventual bloom display.

Although non-invasive, it will aggressively self seed.  Deadhead to prolong the flowering period.  

In addition to the basic color choices, many variations are available in the form of hybrids.  They are typically pastel.

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.

They may require staking due to their height.  Protect from strong winds.  Overwatering or overfertilizing can lead to plants with fewer blooms.  

To prevent self seeding, remove the spent blooms before the seed spreads. 

More information on Cosmos.

See this plant in the following landscape:
Cultivars / Varieties:
  • 'Antiquity'
    1-2'. flowers early, 2" flowers.
  • 'Candy Stripe' Mix
    White flowers with stripes along the length of the petals
  • 'Chocolate'
    Uncommon variety, chocolate scented, deep maroon flowers
  • 'Cosmic' Series
    1' tall with yellow or orange flowers.
  • 'Daydream'
    Pale pink flowers, darker pink towards the center.
  • 'Early Wonder'
    White or pink flowers.
  • 'Gazebo' Mix
    White, pink and red flowers. 3-4' in height.
  • 'Picotee'
    White flowers with reddish-pink edges, light red lines running the length ft the petals, yellow centers.
  • 'Psyche Mix'
    4-5' tall, lavender-pink or white flowers.
  • 'Purity'
    White flower
  • 'Seashells' Mix
    Trumpet-like flowers, petals rolled into tubes. Red, pink and white 3' tall.
  • 'Sensation' Series
    Large flowers in shades of pink, red and white.
  • 'Sonata' Series
    Large pink, white, or red flowers. 1-2' tall.
  • 'Versailles' Series
    Cut flower, large blooms in red, white and pink.
'Antiquity', 'Candy Stripe' Mix, 'Chocolate', 'Cosmic' Series, 'Daydream', 'Early Wonder', 'Gazebo' Mix, 'Picotee', 'Psyche Mix', 'Purity', 'Seashells' Mix, 'Sensation' Series, 'Sonata' Series, 'Versailles' Series
Tags:
#showy flowers#full sun tolerant#heat tolerant#annuals#drought tolerant#easy to grow#fall interest#summer flowers#agressive#long bloom time#naturalizes#self-seeding#cutting garden#spring interest#pollinator plant#wildflower garden#naturalized area#poor soils tolerant#bird friendly#dry soils tolerant#butterfly friendly#Buncombe County Sun and Shade Garden#butterflies#container
 
Cultivars / Varieties:
  • 'Antiquity'
    1-2'. flowers early, 2" flowers.
  • 'Candy Stripe' Mix
    White flowers with stripes along the length of the petals
  • 'Chocolate'
    Uncommon variety, chocolate scented, deep maroon flowers
  • 'Cosmic' Series
    1' tall with yellow or orange flowers.
  • 'Daydream'
    Pale pink flowers, darker pink towards the center.
  • 'Early Wonder'
    White or pink flowers.
  • 'Gazebo' Mix
    White, pink and red flowers. 3-4' in height.
  • 'Picotee'
    White flowers with reddish-pink edges, light red lines running the length ft the petals, yellow centers.
  • 'Psyche Mix'
    4-5' tall, lavender-pink or white flowers.
  • 'Purity'
    White flower
  • 'Seashells' Mix
    Trumpet-like flowers, petals rolled into tubes. Red, pink and white 3' tall.
  • 'Sensation' Series
    Large flowers in shades of pink, red and white.
  • 'Sonata' Series
    Large pink, white, or red flowers. 1-2' tall.
  • 'Versailles' Series
    Cut flower, large blooms in red, white and pink.
'Antiquity', 'Candy Stripe' Mix, 'Chocolate', 'Cosmic' Series, 'Daydream', 'Early Wonder', 'Gazebo' Mix, 'Picotee', 'Psyche Mix', 'Purity', 'Seashells' Mix, 'Sensation' Series, 'Sonata' Series, 'Versailles' Series
Tags:
#showy flowers#full sun tolerant#heat tolerant#annuals#drought tolerant#easy to grow#fall interest#summer flowers#agressive#long bloom time#naturalizes#self-seeding#cutting garden#spring interest#pollinator plant#wildflower garden#naturalized area#poor soils tolerant#bird friendly#dry soils tolerant#butterfly friendly#Buncombe County Sun and Shade Garden#butterflies#container
  • Attributes:
    Genus:
    Cosmos
    Species:
    bipinnatus
    Family:
    Asteraceae
    Uses (Ethnobotany):
    Cutting garden
    Life Cycle:
    Annual
    Recommended Propagation Strategy:
    Seed
    Country Or Region Of Origin:
    Mexico and southwest North America
    Wildlife Value:
    Attracts pollinators, birds and butterflies.
    Play Value:
    Attractive Flowers
    Attracts Pollinators
    Colorful
    Easy to Grow
    Dimensions:
    Height: 2 ft. 0 in. - 4 ft. 0 in.
    Width: 2 ft. 0 in. - 3 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Annual
    Habit/Form:
    Clumping
    Erect
    Growth Rate:
    Rapid
    Maintenance:
    Low
    Texture:
    Medium
  • Cultural Conditions:
    Light:
    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 To Plant:
    12 inches-3 feet
    NC Region:
    Coastal
    Mountains
    Piedmont
    USDA Plant Hardiness Zone:
    2a, 2b, 3a, 3b, 4b, 4a, 5a, 5b, 6b, 6a, 7a, 7b, 8b, 8a, 9a, 9b, 10a, 10b, 11a, 11b
  • Flowers:
    Flower Color:
    Gold/Yellow
    Pink
    Purple/Lavender
    White
    Flower Inflorescence:
    Head
    Flower Value To Gardener:
    Good Cut
    Long Bloom Season
    Long-lasting
    Showy
    Flower Bloom Time:
    Fall
    Spring
    Summer
    Flower Shape:
    Saucer
    Tubular
    Flower Petals:
    7 - 20 petals/rays
    Flower Size:
    1-3 inches
    Flower Description:
    2-4-inch saucer-shaped daisy-like blooms are available in a variety of colors and bloom all season.
  • Leaves:
    Leaf Color:
    Green
    Leaf Value To Gardener:
    Showy
    Leaf Type:
    Compound (Pinnately , Bipinnately, Palmately)
    Leaf Arrangement:
    Opposite
    Leaf Shape:
    Pinnatisect
    Leaf Margin:
    Entire
    Hairs Present:
    No
    Leaf Length:
    3-6 inches
    Leaf Width:
    1-3 inches
    Leaf Description:
    The lacy, thread-like leaves are deeply cut. They have a fine texture.
  • Stem:
    Stem Color:
    Green
    Red/Burgundy
    Stem Is Aromatic:
    No
    Stem Surface:
    Smooth (glabrous)
    Stem Description:
    Unbranched along the erect to ascending stem.
  • Landscape:
    Landscape Location:
    Coastal
    Container
    Meadow
    Naturalized Area
    Landscape Theme:
    Butterfly Garden
    Children's Garden
    Cottage Garden
    Cutting Garden
    Pollinator Garden
    Design Feature:
    Border
    Foundation Planting
    Mass Planting
    Small groups
    Attracts:
    Bees
    Butterflies
    Pollinators
    Resistance To Challenges:
    Drought
    Dry Soil
    Heat
    Poor Soil