Cosmos - Key Growing Information
DAYS TO GERMINATION: 7-10 days at 68-72°F (20-22°C). When planted outside, soil temperature must be above 60°F (16°C).
SOWING: Direct seed: After last frost, once soil temperature is above 60°F (16°C), sow seed thinly in rows, barely covering the seeds. Thin when the first true leaves appear. Tall varieties may benefit from some wind protection. Transplant: Sow seed thinly, barely covering, 5-7 weeks before setting out. Keep soil moist until emergence. When the first true leaves appear transplant into larger containers. Harden off and transplant outdoors after the last frost.
LIGHT PREFERENCE: Sun.
SOIL REQUIREMENTS: Any soil.
PLANT SPACING: 9-12". Wider spacing creates stronger, thicker stems.
HARDINESS ZONES: Annual.
HARVEST: Fresh: Harvest when petals on the first flower are just opening, but not yet flattened. Deadheading is required to have blooms all summer.
USES: Excellent cut flowers. Beds, containers, and mass plantings.
SCIENTIFIC NAME: Cosmos bipinnatus