Cosmos
Feathery, fine-cut foliage and cheerful daisy-like blooms make cosmos one of the easiest, most rewarding annuals you can grow from seed.
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Born to Bloom, Built to Roam
Cosmos bipinnatus hails from the highlands of Mexico and Central America, where it naturalized along roadsides and open fields long before gardeners fell in love with it. Its name comes from the Greek word for 'ordered' or 'ornament,' and once you see a drift of those perfectly arranged petals, you'll understand why.
Available in shades of white, pink, magenta, and bicolor, cosmos attract butterflies, bees, and beneficial insects in droves. The plants are remarkably self-sufficient - they actually perform better in lean, well-drained soil than in rich, overfed beds, which push leafy growth at the expense of flowers.
Planting & care
Direct-sow seeds outdoors after the last frost date, pressing them lightly into the soil surface - they need light to germinate. Thin seedlings to 12-18 inches apart. Transplanting is possible but cosmos resent root disturbance, so handle carefully or start in biodegradable pots.
Resist the urge to fertilize; high nitrogen soil produces tall, floppy plants with fewer blooms. Deadhead spent flowers regularly to extend the blooming season well into fall, or let a few go to seed so the plants self-sow for next year. Tall varieties may need staking in windy spots.
The Lazier You Are, the Better They Bloom
Cosmos thrive on neglect. Overwatering and over-fertilizing are the two fastest ways to get a green, flower-free plant. Once established, they are remarkably drought-tolerant and will reward dry, sunny conditions with a nonstop show of blooms from midsummer through the first hard frost.
How much sun does Cosmos need?
Cosmos grows best in full sun.
How often should you water Cosmos?
Give it about 0.5-1 in per week.
When is Cosmos ready to harvest?
Cosmos is usually ready in 60-90 days to bloom from seed.