How to Grow Cosmos Sulphureus

Last Updated: 11.03.2024

 Cosmos Sulphureus is an easy to grow plant with beautiful yellow flowers! Here’s how to maintain it easily for best blooms!

How to Grow Cosmos Sulphureus

Cosmos sulphureus is a stunning plant with sunny yellow flowers that’s sure to brighten up any garden bed or container!

Cosmos Sulphureus Information

Cosmos sulphureus, is a species of flowering plant native to Mexico, Central America, and northern South America. It belongs to the family Asteraceae and has a bright yellow color that makes it a beloved ornamental plant in gardens and parks worldwide. It typically grows from 2-6 feet tall and produces small, aromatic leaves with a unique spicy scent.  

The plant blooms from mid-summer to fall, producing large yellow or orange-yellow flowers with a dark center disk that attracts bees, butterflies, and other pollinators.

Common Names: Yellow cosmos or Sulphur cosmos 

Explore How to Grow Tabernaemontana Divaricata! here

How to Propagate Cosmos Sulphureus

Propagate Cosmos Sulphureus
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  • Plant the seeds in the garden after the last frost or start them indoors 4-6 weeks before the last frost. 
  • Thin out the seedlings once they sprout to allow them to grow better. 
  • Keep the soil moist and fertilize the plants once or twice during the growing season. 
  • Allow some of the flowers to turn brown and dry out to produce seeds. 
  • Collect the seeds and store them in a cool, dry place until the next growing season. 

Cosmos sulphureus can also self-seed, so you may see new plants growing on their own in the following year. If you want to control the spread of the plant, deadhead spent flowers before they produce seeds.

Requirements to Grow Cosmos sulphureu 

Cosmos Sulphureus in Garden


Cosmos sulphureus prefers full sunlight, requiring at least 6 to 8 hours of direct sunlight per day to thrive. If you are planting cosmos in a location that does not receive full sun, the plant may not produce as many flowers.


Cosmos sulphureus can be grown in a variety of soils, but it prefers well-draining soils with a pH range between 6.0 and 7.5. The soil should be rich in organic matter, such as compost, to help the plant grow well. In India, it is best to plant cosmos in sandy loam or red loam soil, which are common soil types in many parts of the country. 


Sulfur cosmos is relatively drought-tolerant, but it still requires regular watering, especially during hot and dry weather. It is important to avoid overwatering, as this can lead to root rot and other fungal diseases.

Moisten the growing medium only when the topsoil feels a little dry to the touch.


Cosmos sulphureus grows best in warm weather, with daytime temperatures between 21°C to 29°C (70°F to 85°F) and nighttime temperatures between 10°C to 15°C (50°F to 60°F). 

Cosmos Sulphureus Care 

Cosmos Sulphureus Care 


The plant benefits from a balanced fertilizer, such as a 10-10-10. Use it once in 2-3 months to promote the growth. You can also go for a handful of gobar ki khaad every month, too.


Cosmos sulphureus doesn’t require heavy pruning. However, deadheading spent flowers can promote continuous blooming and prevent self-seeding.

Pinching back the growing tips of the plants when they are 6 to 8 inches tall can encourage bushier growth and more flowers. 

Pest and Diseases  

Sulfur cosmos can be affected by fungal diseases like powdery mildew and rust in humid weather conditions. To prevent fungal diseases, avoid overwatering, provide good air circulation, and plant in well-draining soil.

In case of a pest infestation, use an insecticidal soap or neem oil to control the pests. 

 Here is the link to Growing Bauhinia Purpurea in India

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