Planting. They are even drought-tolerant. Depending on the type of flower, cosmos can grow anywhere between 18 to 60 inches tall. If you are growing cosmos from seeds, be mindful that it takes about 7 weeks to first bloom. After that, though, your flowers should continue to bloom until the next frost.
Growing Cosmos from Seed. Cosmos will only grow to about 21 to 22 inches, and they’re perfect as part of your landscaping or container gardening. While compact Cosmos sulphureus are great for container gardening, Cosmos bipinnatus reaches six feet or higher with a tendency to topple over. To keep your cosmos in bloom, keep them trimmed.
While bedding plants are sold in spring, cosmos are simple and inexpensive to grow from seeds. Plant them in full sun (in very hot regions, cosmos can take afternoon shade) and give them protection from strong winds. Cosmos tolerates a wide range of soil types, including poor soil.
How To Plant And Grow Cosmos From Seeds. Cosmos seeds produce hardy flowering plants that thrive with heat, sun and little water. These annual varieties grow anew each year. They come in colors from white to yellow to red and grow to heights ranging from 2 to 7 feet. There is a cosmoses …
How to Grow Cosmos. You can also start Cosmos indoors in February to early March for transplanting late March to mid-April. Seeds will sprout in 3-10 days. Optimal temperature for germination: 21-25°C (70-75°F). Starting Sow seeds very shallowly only a few millimeters (1/8″) deep. Thin or transplant to 20-25cm (8-10″) apart.
Growing Cosmos From Seeds Indoors. Plant the cosmos seeds 1 to 1-1/2 inches part. Fill in the shallow rows with 1/2 of an inch of the seed-starting mix. Fill a spray bottle with water and drench the surface of the soil in the germination tray. Check on the germination tray every day, misting the surface of the soil to keep the growing media moist as needed.