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Cosmos sulphureus is often confused with:
Coreopsis lanceolata flowers and leaves
Dahlia Dahlia 'Knockout' Mystic Illusion flower
Native alternative(s) for Cosmos sulphureus:
Coreopsis lanceolata flowers and leaves
Plants that fill a similar niche:
Cosmos bipinnatus Bumblebee pollinator
Tithonia rotundifolia Form in bloom
Baptisia tinctoria Baptisia tinctoria

Sulphur Cosmos Cosmos sulphureus

Phonetic Spelling
KAHS-mos sul-FER-ee-us
Description

Klondike cosmos is a fast growing annual with golden-yellow or orange flowers in the Asteraceae (daisy) family.  It can grow up to 6 feet tall providing sticking color from summer until the first frost. The ‘Cosmic’ series will give you lots of 2-inch double and semi-double bright, non-fading blooms in shades of orange, red, and yellow, and will get 12 to 18 inches tall on well-branched plants.

Plant cosmos in a location that receives at least a half-day of direct sunlight in moist to dry, porous soils. 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; 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.

Use in the background as a bedding plant or in a cut flower garden.

Quick ID Hints:

  • dimorphic involucral bracts in two rows
  • opposite, pinnatifid leaves
  • small heads 1-2" with orange ray flowers

Insects, Diseases, and Other Plant Problems:  Aphids and Japanese beetles are occasional bests.  Bacterial wilt and canker are occasional diseases.  It reseeds easily and can become weedy.

 

 

More information on Cosmos.

See this plant in the following landscape:
Cultivars / Varieties:
  • 'Bright Lights'
  • 'Lemon Twist'
  • 'Sunny Gold'
  • 'Sunny Red'
'Bright Lights', 'Lemon Twist', 'Sunny Gold', 'Sunny Red'
Tags:
#cultivars#showy flowers#full sun tolerant#heat tolerant#annuals#easy to grow#weedy#orange flowers#fall interest#fast growing#summer flowers#dye plant#deer resistant#bedding plants#self-seeding#cutting garden#fantz#poor soils tolerant#dry soils tolerant#butterfly friendly#yellow dye plant
 
Cultivars / Varieties:
  • 'Bright Lights'
  • 'Lemon Twist'
  • 'Sunny Gold'
  • 'Sunny Red'
'Bright Lights', 'Lemon Twist', 'Sunny Gold', 'Sunny Red'
Tags:
#cultivars#showy flowers#full sun tolerant#heat tolerant#annuals#easy to grow#weedy#orange flowers#fall interest#fast growing#summer flowers#dye plant#deer resistant#bedding plants#self-seeding#cutting garden#fantz#poor soils tolerant#dry soils tolerant#butterfly friendly#yellow dye plant
  • Attributes:
    Genus:
    Cosmos
    Species:
    sulphureus
    Family:
    Asteraceae
    Uses (Ethnobotany):
    The flowers can be used to make a yellow dye.
    Life Cycle:
    Annual
    Recommended Propagation Strategy:
    Seed
    Country Or Region Of Origin:
    Mexico to Central America
    Wildlife Value:
    Attracts pollinators and butterflies
    Play Value:
    Attractive Flowers
    Attracts Pollinators
    Colorful
    Easy to Grow
    Dimensions:
    Height: 2 ft. 0 in. - 3 ft. 0 in.
    Width: 1 ft. 0 in. - 3 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Annual
    Habit/Form:
    Clumping
    Growth Rate:
    Rapid
    Maintenance:
    Medium
  • Cultural Conditions:
    Light:
    Full sun (6 or more hours of direct sunlight a day)
    Soil Texture:
    Clay
    Loam (Silt)
    Sand
    Soil pH:
    Acid (<6.0)
    Neutral (6.0-8.0)
    Soil Drainage:
    Good Drainage
    Available Space To Plant:
    3 feet-6 feet
    6-feet-12 feet
    12-24 feet
    24-60 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
    Orange
    Red/Burgundy
    Flower Value To Gardener:
    Good Cut
    Long Bloom Season
    Long-lasting
    Showy
    Flower Bloom Time:
    Fall
    Spring
    Summer
    Flower Shape:
    Saucer
    Flower Size:
    1-3 inches
    Flower Description:
    Produces daisy-like flowers (to 2.5” diameter) with yellow discs and yellow rays. Terminal, head to 2" diam., on long peduncles 4-8" long. Involucral bracts in two rows; outer row spreading, narrow, inner row appressed to ray flowers, broad, membranous, pigmented. Ray flowers rich orange or pale reddish-yellow, obovate, notched at apex. Disc flowers yellow.
  • Leaves:
    Leaf Color:
    Green
    Leaf Type:
    Compound (Pinnately , Bipinnately, Palmately)
    Leaf Arrangement:
    Opposite
    Leaf Shape:
    Lanceolate
    Pinnatifid
    Hairs Present:
    No
    Leaf Length:
    > 6 inches
    Leaf Description:
    Compound leaves are up to 12 inches long with 2-3 deeply cleft leaflets.
  • Stem:
    Stem Is Aromatic:
    No
  • Landscape:
    Landscape Location:
    Coastal
    Meadow
    Naturalized Area
    Landscape Theme:
    Butterfly Garden
    Children's Garden
    Cottage Garden
    Cutting Garden
    Drought Tolerant Garden
    Pollinator Garden
    Design Feature:
    Border
    Foundation Planting
    Mass Planting
    Attracts:
    Butterflies
    Pollinators
    Problems:
    Weedy