If you’re looking for an easy going annual that has the relaxed disposition of a wildflower, cosmos are a fantastic choice. Its flowers have a daisy-like look. The blooms are available in a selection of colors- from whites and deep pinks to yellows and oranges. The foliage has a lacy and delicate appearance. But don’t let that tender appearance fool you. Cosmos can handle some of the most unwelcoming conditions, like heat and drought, with its tough nature.
This rather lanky 2 to 6 foot tall sun loving flower is versatile for plantings. Its full height will depend on the variety you choose. It’s lovely when used in flower beds and borders. And, in spite of its height, a smaller variety of cosmos makes a stunning container flower.
Cosmos is an indigenous species to Mexico and South America. Mexican priests who admired the plant for the uniformity of the flower petals named them. In Greek, cosmos means “ordered universe” or “harmony.” The blooms do represent orderliness and harmony. They are also just simply beautiful!
How to Grow and Care for Cosmos
Cosmos are easy to grow. They can be started from seed once the ground begins to warm in the spring. Spread the seed directly over the surface of the soil in an area where the plant will receive 8 to 10 hours of sun each day. Rake gently to barely cover the seeds.
Cosmos have no special soil requirements. In fact, poor soil conditions are optimal for cosmos. They do prefer their soil to be well draining though. So, for the first 2 weeks after planting, keep the ground well watered. Once seedlings have developed, cosmos will not be a bother at all. Just water them weekly. Or wait until your cosmos become a bit droopy and then give them a drink.
In cooler regions, to get a jump start on growth, cosmos can be purchased at most garden centers and nurseries. Transplant your cosmos in a sunny location. Cosmos grown in full, hot sun will be the happiest and provide the most blooms. So after planting your cosmos, just sit back and enjoy. The butterflies will love them, too.
If you would like to prolong the blooms, cut your plant back to 1 foot once it has gone to seed. If there is time left in the season before the first frost, your cosmos will grow again and re-bloom. And, if you drop your seed heads onto the ground, the seeds will develop into new plants during the same year. Or, in some areas, the seeds are known to develop into plants the following growing season if allowed, too.
Cosmos: Pests and Problems
Cosmos are not typically susceptible to pests or disease. They can become prone to powdery mildew if they don’t receive the air circulation and sunshine they need, so be sure to give your cosmos plenty of both.
Excess water or not enough water will be a problem too, so keep an eye on your cosmos plant. Water it moderately and regularly. That will keep it healthy. If it droops, it needs more water.
Cosmos Varieties to Consider
‘Tetra Versailles Red Cosmos’ has a deep magenta flower that is very distinct. The perfection of this flower is dizzying if you stare at it long enough!
‘Cosmos Psycho White’ is for the purists out there. This heavenly white flower is extra dimensional with its ruffled petals.
‘Ladybird Dwarf Lemon’ has a smaller sized bloom that is citrusy yellow in color. This variety is a good choice for a container.
‘Can’t Make up My Mind Collection’ is for those cosmos lovers who just want them all! With fourteen different varieties combined in this mix, your garden will be full of cosmos in all of its cosmic shapes, colors, and sizes. You can’t go wrong with this choice!
Want to learn more about growing cosmos?
Check out these resources:
Cosmos Produces Cosmic Beauty from Texas A&M AgriLife Extension Service
Cosmos spp. Family Asteraceae (Sunflower family) from University of California Agriculture and Natural Resources
My cosmos are very healthy, however, they are not blooming yet and show no buds for blooming. What would cause this?