This variety of Cosmos is native to Mexico and Central and South America. As such, it can tolerate growing with very little water after the seeds germinate. It was introduced into English horticulture in the late 18th century.
Diablo Cosmos is of the species Cosmos sulphureus. This species of flower was preferred by the Korean-Japanese botanist and plant breeder Dr. Woo Jang-choon in his program of planting cosmos flowers along the highways and railroads in Japan and Korea.
In 1974 Diablo Cosmos won the All-America Selections award for Flowers.
You can sow the seeds for Diablo Cosmos directly into your garden soil after the last frost. Sow them 1/8 of an inch deep and they will germinate in 3-10 days. These plants prefer full sun to partial shade and need very little attention. As the plants grow, thin them to 18-36 inches apart and they may require staking to keep them upright.