Zone 6 · Cosmos
Planting Cosmos in Zone 6
Cosmos bipinnatus
✅ Cosmos thrives in zone 6 (hardy 2–11)
Can I plant today?
✅ Safe to plant Cosmos outside
Last frost has passed. Start indoors 4 weeks before last frost or direct-sow after.
Evaluated for April 27, 2026 ·
Zone's last frost
around April 15
Zone's first frost
around October 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 6
Start indoors 4 weeks before last frost or direct-sow after.
💡 In zone 6, start seeds indoors around March — 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.
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