Cosmos - Key Growing Information
SOWING: Transplant - Sow into 50-cell plug flats 5-7 weeks before last frost, covering seeds lightly. Harden-off and transplant outdoors after last frost. Direct seed - Sow after last frost, once soil temperature is above 60°F (16°C), covering seeds lightly. Pinching encourages branching.
LIGHT PREFERENCE: Sun.
PLANT HEIGHT: Varies. Tall varieties may benefit from some wind protection.
PLANT SPACING: 9-12". Wider spacing creates stronger, thicker stems.
HARDINESS ZONES: Annual.
HARVEST: Petals just opening, but not yet flattened. Deadheading is required to have blooms all summer.
SOIL REQUIREMENTS: Any soil.
USES: Excellent cut flowers. Beds, containers, and mass plantings.
SCIENTIFIC NAME: Cosmos bipinnatus