Cosmos

Cosmos flowers best in average to lean, well-drained soil with a pH of 6.0-8.0. Avoid rich compost and heavy fertilizer that produce floppy foliage, and support tall plants in windy sites.

Sun

Full sun

Water

Light; drought tolerant

Spacing

12 in

First harvest

50–60 days

Tips

• Sow seeds about 1/4 inch deep and thin seedlings to about 12 inches apart, farther for tall cultivars.
• Water seedlings regularly until established, then water deeply only when the soil dries during prolonged dry spells.
• Skip routine fertilizer in average garden soil and feed lightly only if plants show clear nutrient deficiency.
• Watch for aphids on tender shoots and dislodge them with a firm spray of water.
• Deadhead or cut flowers often to prolong bloom and remove seed heads if unwanted self-sowing is a concern.