Cosmos
Common Name(s):
- Phonetic Spelling
- KAHS-mos
- Description
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Cosmos is an easy-to-grow flower that can reseed itself and grow in hot, dry conditions, making it a good choice for North Carolina gardens. The hardy annuals will give you blooms from summer to frost.
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. 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.
Be cautious not to overwater your plants. That and over-fertilizing can lead to the plant producing fewer flowers.
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.
Insects, Diseases, and Other Plant Problems: Issues effecting this plant include aphids, gray mold, stem canker and powdery mildew. Allowing good airflow will help avoid diseases.
- See this plant in the following landscape:
- Extension Master Gardenerâ„ Demonstration Garden, Durham Co.
- Cultivars / Varieties:
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Cosmos bipinnatus
- 'Picotee'
White flower with a crimson border - 'Purity'
White flower - 'Sea Shells'
White, pink or red tube-shaped petals
Cosmos sulphureus
- 'Picotee'
- Cosmos bipinnatus, Cosmos sulphureus, 'Picotee', 'Purity', 'Sea Shells'
- Tags:
- Cultivars / Varieties:
-
-
Cosmos bipinnatus
- 'Picotee'
White flower with a crimson border - 'Purity'
White flower - 'Sea Shells'
White, pink or red tube-shaped petals
Cosmos sulphureus
- 'Picotee'
- Cosmos bipinnatus, Cosmos sulphureus, 'Picotee', 'Purity', 'Sea Shells'
- Tags:
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Attributes:
- Genus:
- Cosmos
- Family:
- Asteraceae
- Uses (Ethnobotany):
- Cutting garden
- Life Cycle:
- Annual
- Recommended Propagation Strategy:
- Seed
- Country Or Region Of Origin:
- Lesser Sunda Island, Southern America, Northern America, Mexico
- Wildlife Value:
- Attracts pollinators and butterflies
- Play Value:
- Attractive Flowers
- Attracts Pollinators
- Colorful
- Easy to Grow
- Dimensions:
- Height: 1 ft. 0 in. - 6 ft. 0 in.
- Width: 2 ft. 0 in. - 4 ft. 0 in.
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Whole Plant Traits:
- Plant Type:
- Annual
- Woody Plant Leaf Characteristics:
- Deciduous
- Habit/Form:
- Clumping
- Erect
- Growth Rate:
- Rapid
- Maintenance:
- Low
- Texture:
- Medium
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Cultural Conditions:
- Light:
- Full sun (6 or more hours of direct sunlight a day)
- 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
- 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, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b, 10a, 10b, 11a, 11b
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Flowers:
- Flower Color:
- Gold/Yellow
- Orange
- Pink
- Purple/Lavender
- Red/Burgundy
- 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
- Flower Petals:
- 7 - 20 petals/rays
- Flower Size:
- 3-6 inches
- Flower Description:
- The flowers are saucer shaped, and daisy like. There are many colors available. They sit atop the long, slender stems. Deadhead spent flowers to prolong bloom, but leave enough flower heads for self seeding to take place.
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Leaves:
- Woody Plant Leaf Characteristics:
- Deciduous
- Leaf Color:
- Green
- Leaf Arrangement:
- Opposite
- Leaf Shape:
- Pinnatisect
- Leaf Margin:
- Lobed
- Hairs Present:
- No
- Leaf Description:
- Finely cut green leaves in thread-like sections
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Stem:
- Stem Is Aromatic:
- No
- Stem Description:
- Long, slender stems.
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Landscape:
- Landscape Location:
- Coastal
- Container
- Meadow
- Naturalized Area
- Patio
- Landscape Theme:
- Butterfly Garden
- Children's Garden
- Cottage Garden
- Cutting Garden
- Fairy Garden
- Pollinator Garden
- Design Feature:
- Border
- Foundation Planting
- Mass Planting
- Attracts:
- Bees
- Butterflies
- Pollinators
- Resistance To Challenges:
- Drought