Cosmos Flower How To Grow. The plants do not need soil for the very rich though rich soil encourages more foliage and bloom. Grow cosmos in moist but well-drained soil in full sun.
Cosmos dont need any special soil preparation. Sometimes depending on the climate. May 18 2021 Planting Just sow seeds lightlyabout -inch deep and 1218 inches apart after the danger of frost has passed.
If you want to get a head start on your cosmos before the weather warms enough plant your seeds in a tray indoors.
Full sized specimens will crowd out the other plants and their roots will dominate available soil. They grow best in free-draining soil and prefer a sunny location protected from strong winds. Hot dry conditions along with poor to average soil are optimum conditions for growing cosmos. This will give larger plants that are closer to blooming in pots.