How to Grow Cosmos Atrosanguineus

Select chocolate cosmos as a perennial landscaping species if you live in U.S. Department of Agriculture plant hardiness zones 7 through 9. As with all types of cosmos, this member of the vast daisy family is a native plant of the Southwestern United States and parts of Mexico, meaning it possesses little cold hardiness.

Grow Cosmos atrosanguineus in a full sun site. Utilize this kind of cosmos in the forefront of your perennial gardens to take advantage of the fragrance of the flowers, which is not strong enough for someone to appreciate when you place chocolate cosmos too far away from foot traffic.

Put your Cosmos atrosanguineus tubers into soil that is of medium moisture and ground that drains well. In areas that are too damp, the tubers may rot away. This species of cosmos has some ability to grow in dry soil. Adding organic matter to the soil greatly enhances the chances of this flower growing.

Bring the tubers from which Cosmos atrosanguineus develop inside in the winter if you grow this species in zones colder than USDA zone 7. Dig them up and store them inside to protect them from the potential cold. One option you may consider in these colder areas is to grow Cosmos atrosanguineus in a container, enabling you to move it indoors as frost threatens and winter closes in. If you choose to grow chocolate cosmos as an annual, you can simply leave it outdoors for the winter.

Divide the tuberous roots of chocolate cosmos early in the springtime and transplant them elsewhere in your landscape. Dig them up carefully to avoid damaging them, usually no later than April to ensure they generate flowers. Chocolate cosmos breaks its dormant stage later in the spring, usually no later than May.