Plant Profile: Cosmos bipinnatus

Tall Cosmos showcases a stunning array of maroon, pink, lavender, and white flowers that can reach heights of up to 4 feet. There are numerous cultivars and varieties to choose from.

For optimal growth, plant cosmos in an area that receives at least six hours of direct sunlight each day. Sow the seeds outdoors once the threat of frost has passed and the soil temperature has risen to a minimum of 65 degrees Fahrenheit. Lightly rake the seeds into the soil, as planting them too deeply can impede germination. Maintain moisture in the soil for 5 to 10 days following seeding; germination typically occurs within 7 to 21 days. Cosmos requires minimal care to produce a vibrant display of blooms throughout the summer. Taller varieties may need support in windy conditions or during storms.

When spring-planted cosmos develops a significant amount of dried seed, refrain from removing the plants. To promote re-blooming, trim the plants back to a height of 12 to 18 inches. They will flower again within a month, and the cut seeds will fall to the ground, germinating in the warm soil and enhancing both the density of your plant population and the overall bloom display.

For further details on Cosmos, please refer to additional resources.