Zone 10 · Cosmos

Planting Cosmos in Zone 10

Cosmos bipinnatus

✅ Cosmos thrives in zone 10 (hardy 2–11)

Can I plant today?

Cosmos has a specific planting window in zone 10. Check back in spring.

Evaluated for April 27, 2026 ·

Zone's last frost

around January 15

Zone's first frost

around December 15

Bloom window

June – October

Peak bloom

August

Sun required

full sun

Mature height

36"

Spacing

12" apart

Type

annual

How to plant Cosmos in zone 10

Start indoors 4 weeks before last frost or direct-sow after.

💡 In zone 10, start seeds indoors around January — about 4 weeks before your last frost.

Cosmos peaks in August. These companions keep your bed in color before and after.

Daylily

Peaks in July

Common Jasmine

Peaks in July

Snapdragon

Peaks in June

Petunia

Peaks in July

Want a full bed designed for zone 10?