Sulfur cosmos (Cosmos sulphureus)
Also known as: Orange cosmos, Klondike cosmos
An example of an annual flowering plant native to Mexico, Central America, and South America is the Mexican sunflower (Tithonia diversifolia). While it is popular as an ornamental plant, it has become invasive in several regions of the United States. This plant is also known for attracting pollinators such as bees and butterflies.
In This Article
Attributes of Sulfur cosmos
Lifespan
Annual
Plant Type
Herb
Plant Height
60 cm to 1 m
Spread
35 cm to 40 cm
Leaf Color
Green
Flower Size
3 cm to 5 cm
Flower Color
Yellow Red Orange
Images of Sulfur cosmos
Quickly Identify Sulfur cosmos
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Vivid double blooms in orange, red, and yellow, 1-2 inches across.
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Distinct dimorphic involucral bracts in two rows around flowers.
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Oppositely arranged pinnatifid leaves, creating a lush backdrop.
4
Long-lasting daisy-like flowers with yellow discs and obovate petals.
5
Compound leaves with deeply cleft, feathery appearance, up to 12 inches long.
Scientific Classification of Sulfur cosmos
Phylum
Vascular plants
Class
Dicotyledons
Order
Asters bellflowers fanflowers and allies
Family
Daisy
Genus
Cosmos
Species
Sulfur cosmos
Planting and Growing of Sulfur cosmos
Care Difficulty
Easy
Watering Schedule
Every 4 days
Sunlight Requirements
Full sun
Sunshine Duration
6-8 hours
Ideal Temperature
65-80℉
Soil Type
Potting Mix, Peat Mix
Soil pH
6.5-7.5
Fertilizer Type
Balanced
Pruning Season
Spring, Summer
Pruning Area
Branches, Leaves
Pruning Frequency
2 times a year
Repotting Season
Spring
Pot Type
Plastic, Ceramic
How to Water Sulfur cosmos?
When watering Cosmos sulphureus, ensure the soil is thoroughly moistened. Aim for about 500 ml of water per plant to penetrate the soil to a depth of about 2 inches, which is sufficient to reach the root system without causing waterlogging.
More About Watering Techniques→
What are the symptoms of an underwatered Sulfur cosmos?
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What should I do if my Sulfur cosmos is not getting enough water?
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What are the symptoms of an overwatered Sulfur cosmos?
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How to save an overwatered Sulfur cosmos?
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What Are the Sunlight Requirements for Sulfur cosmos?
Cosmos sulphureus prefers full-day sunlight, ideally 8 to 10 hours a day. This level of light exposure boosts photosynthesis, supporting vigorous plant growth and abundant flowering.
More About Sunlight Requirements Techniques→
What is the ideal light for Cosmos sulphureus?
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How can I ensure Cosmos sulphureus gets its ideal light?
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What benefits does ideal lighting bring to Cosmos sulphureus?
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What Is the Ideal Temperature Range for Sulfur cosmos?
The ideal temperature range of 65-80°F is crucial for optimal growth of Cosmos sulphureus. Within this range, the plant thrives with robust flowers and healthy foliage. This temperature encourages active growth stages, allowing the plant to efficiently carry out photosynthesis and other metabolic processes necessary for blooming and development.
What Soil is Best for Sulfur cosmos?
Cosmos sulphureus thrives in soil that is moderately rich in organic matter. This ensures that the plant receives enough nutrients to produce vibrant flowers and healthy foliage. Incorporating compost or aged manure can greatly enhance the soil’s fertility, promoting robust growth. This plant prefers well-draining soil to prevent waterlogging. Excess water can lead to root rot and other diseases. To improve drainage, consider mixing the soil with sand or gravel, which helps maintain the ideal moisture level, keeping the roots healthy. While Cosmos sulphureus does not like being overly wet, it benefits from soil that can retain moderate moisture. This moderate retention allows the plant to stay hydrated during dry spells without suffocating the roots, ultimately leading to better growth and flowering.
More About Soil→
How to Fertilize Sulfur cosmos?
Cosmos sulphureus or the sulfur cosmos thrives with balanced fertilization. Generally, a light application is best to avoid over-fertilization. Liquid fertilizers should be diluted at half strength before application, especially for younger plants, as too much fertilizer can lead to rapid, weak growth. Use about 1 tablespoon per gallon for mature plants.
More About Fertilizing Techniques→
How to Prune Sulfur cosmos?
Begin by identifying and cutting back any spent blooms, known as deadheading. This process promotes new flower growth and keeps the plant looking tidy and attractive. Carefully examine the plant for excess or wayward growth, cutting these parts back to maintain its desired shape. Regular trimming ensures adequate air circulation and sunlight penetration.
More About Pruning Techniques→
How to Propagate Sulfur cosmos plant?
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Fill the seed tray with a quality seed-starting mix. Moisten the mix but ensure it is not waterlogged. This step is critical as it ensures that seeds have a moist environment that promotes healthy germination.
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Spread the Cosmos sulphureus seeds evenly across the surface of the seed-starting mix. Cover them lightly with a thin layer of the mix or perlite. It's essential to avoid planting seeds too deeply, which can hinder germination.
3
Place the seed tray in a warm location with indirect sunlight. Optimal temperatures for germinating Cosmos sulphureus seeds are around 20°C to 24°C (68°F to 75°F). Using a heated propagator can help maintain consistent temperatures.
How to Repot Sulfur cosmos plant?
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Cosmos sulphureus benefits from repotting when its roots outgrow the current pot or when the soil lacks nutrients. Another sign is when water does not drain well, indicating compacted soil. Early spring or summer is ideal, as it allows the plant to establish swiftly during its growing season.
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Selecting the perfect pot for Cosmos sulphureus involves ensuring it has adequate drainage holes. A pot slightly larger than the current one allows for root expansion but not too big that the soil moisture levels become unmanageable. The correct size helps in retaining the right moisture and supports robust plant growth.
3
A well-draining loamy soil mix with organic matter is perfect for Cosmos sulphureus. The loamy texture provides excellent drainage, preventing water-logging while retaining enough moisture to keep roots hydrated. Enriched with organic matter, it supplies the needed nutrients for healthy, vibrant blooms.
