Cosmos sulphureus


  • Compact, round shaped habit
  • Floriferous plants
  • Double flowers in happy colors
  • Attracts beneficial insects
Crop Time
Spring: 7 - 8 weeks
Height ∅
12 ″ / 30 cm
Sun - Partial shade
Seed Form
Detailed Seed
Best Uses
Bedding, Landscape

Culture guide


Plants for the border, attractive pot plants with intense color.

Sow time

February-End July

Sowing method

2-3 seeds per plug, can be sown directly into final pot


Germinates in 5-8 days at 65-70 °F (18-21 °C). Cover seed after sowing.

Growing on

Transplant plugs after 4-5 weeks. Grow on at temperatures of 60-65 °F (15-18 °C).


Use a well-drained, growing substrate with 20-30 % clay, 1-2 kg/m³ complete balanced fertilizer, iron-chelate, micronutrients, pH: 5.5-5.8.


Grow at 15-17 °C or outdoors. Cosmos does not tolerate frost.


Moderate fertilization levels are required. Fertilize the crop weekly with 100-150 ppm nitrogen, using a complete balanced fertilizer. Avoid high ammonium and high nitrogen levels.

Stage I Starts with the radicle breaking through the testa. The roots are touching the medium. Ends with fully developed cotyledons.
Stage II Starts from fully developed cotyledons. Ends with the fully developed true leaf or true leaf pair.
Stage III Starts from the fully developed true leaf or true leaf pair and ends with 80% of the young plants being marketable.
Stage IV All young plants are ready for sale and in the process of being hardened off. This stage lasts about 7 days.

The cultural recommendations are based on results from trials conducted under Central European conditions. Different conditions in other parts of the world may lead to deviations in results achieved.

Colors of the series