Zone 10 · Cosmos
Planting Cosmos in Zone 10
Cosmos bipinnatus
✅ Cosmos thrives in zone 10 (hardy 2–11)
Loading planting window…
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.
Pair with these for continuous bloom
Cosmos peaks in August. These companions keep your bed in color before and after.
Want a full bed designed for zone 10?
Sign up free. GimmeBlooms builds a bloom-succession layout withCosmos and 3–5 perfect companions.
Design my bed →