Chocolate cosmos are a perennial variety of the cosmos flower. The cosmos are named for their prolific round flowers that seem to emulate the glory of the skies above. The chocolate cosmos are so named for the color of their petals and their scent.
Chocolate cosmos are a shorter variety of the cosmos, growing to about 18 inches in height. They grow from a tuber-like root structure. When not in bloom, the leaves seem unassuming, just a short cluster of messy, dahlia-like leaves. The flowers quickly overwhelm the leaves when in bloom.
The petals are a rich, dark, chocolaty maroon and are soft and velvety to the touch. The color can look dark brown or even black in the evening, which makes the chocolate cosmos popular in Gothic style gardens. The sweet scent is sometimes described as a being like a cup of hot coco or a chocolate bar.
Where to Grow
Originally native to Mexico, chocolate cosmos prefer lots of sun and well-drained soil. The original plant is essentially extinct, but you can find clones in garden stores from time to time. The clones are sterile or will occasionally produce fertile seeds that do not breed true. The only way to grow additional plants for your garden is to wait for the root to expand and divide it.
Plant the roots in a sunny location. All varieties of cosmos will flower more weakly in the shade. Provide well-draining soil and water minimally. If the flowers seem to wilt in the sun, try providing a bit of water. Keep in mind, however, that too much water will result in damaged roots or fewer flowers.
How to Grow Chocolate Cosmos
Like most varieties of cosmos, chocolate cosmos should blossom from spring right until the first frost of winter. Make sure to give them just enough fertilizer. Cosmos developed in harsh environments. If they get too much in the way of nutrients, they will grow leaves and skip the flowers. A little all-purpose fertilizer at the beginning of the flowering season and at the middle is all you need.
Deadhead your flowers. Remove the flowers as soon as they fade to help your plant save energy for more flowers. This will encourage the plant to throw up more blooms for a long as possible.
Chocolate Cosmos in Winter
Chocolate cosmos, while native to warmer climates, can be grown in almost any climate zone. The flowers will bloom once the weather warms and continue through autumn. When the weather turns cold, the plant will die back to the roots and go dormant. You have several options for wintering your chocolate cosmos.
Provide a layer of mulch and leave the roots in the ground. Dig up the roots and store them inside. Place each root in its own pot. Keep the soil slightly damp over the winter, and replant in the spring.
If you grow your chocolate cosmos in a container, bring the container inside when the weather turns cold. This can extend the bloom cycle of your plant, but eventually, the cosmos will go dormant.