Family: Asteraceae
Common name: Sulphur cosmos, Yellow cosmos
It is impossible not to love these beautiful Cosmos plants with their dainty yellow flowers, that bloom in abundance. The plants can grow to a height of 5-7 feet with thin, breakable stems. Very tall and gangly plants might need stakes for support so that they don’t fall over.
The leaves are beautiful, pinnate and dark green. Sulphur cosmos flowers look awesome in their yellow and orange splendor, though some variants with red flowers are also available. A very close relative, Cosmos Bipinnatus has pink, purple and white flowers and looks very similar to Sulphur cosmos.
Sulphur Cosmos flowers have very delicate petals or ray florets, which are partially double-layered with 8-15 petals. They also have tiny disc florets arranged at the center of the flowers. The flowers are very attractive to butterflies, bees and other insects that help in pollination.
Once the petals die, the flowers form seeds, which are initially brownish green, later turning black. These tiny spiky seeds will fall on the ground and germinate by itself. They have a good germination rate, with seeds producing baby plants within 10-14 days.
Since these plants produce abundant flowers, they need good sunlight and fertilization. But they are drought-tolerant and must not be watered too frequently. In fact, it’s good to ensure that your Cosmos plants have well-drained soil.
Young shoots and flowers are eaten raw or cooked. The flowers are used to make orange and yellow dye for fabrics. Sulphur cosmos plants also have medicinal properties, and is used in treatment of malaria, inflammations, gastric ulcers and liver diseases.
Propagation is through seeds, which have a very good success rate.
