Cosmos Seeds,
Fizzy Rose Picotee

Plant cosmos after the last frost, when soil temperatures are at least 60 F. In colder climates, start seeds 3-4 weeks before the last expected frost and transplant them outdoors only once the weather has warmed. Cosmos typically bloom 60-90 days after sowing and continue flowering until the first frost. To find the best planting time, check your local area's frost dates. If you're not sure how to do that, consult our blog post 'Our Experts Answer Questions, Share Resources.'

Lightly press the seeds into the soil 1/8-1/4 inch deep, but do not cover them heavily, as they need light to germinate. Space plants about 10 inches apart to ensure good airflow. Keep the soil evenly moist until germination, which takes 7-14 days. Alternatively, start seeds indoors in a light, well-draining seed-starting mix. Transplant seedlings outdoors once they are strong enough and the weather has warmed, being careful not to disturb the roots.

Avoid excessive fertilization, as too much nitrogen encourages leaf growth at the expense of flowers. Once established, cosmos are drought tolerant and require minimal watering. Be careful not to overwater, as it can lead to weak stems and fewer blooms. Taller plants may need staking in windy areas. If plants become too tall or leggy, trim them back by one-third for bushier growth.

• Cosmos are insect pollinated, and there may be some crossing between varieties in the garden. You can enjoy the mixing or use caging techniques and hand pollination to avoid crossing.
• Saving seeds from cosmos is easy: simply allow the heads to brown and dry on plants and collect seeds. Store in a cool, dry, dark place over winter.