When to Plant Cosmos in Bozeman, Montana (59719)

Location

Bozeman, Montana

ZIP Code

59719

USDA Zone

Last Frost

Sunday, May 10, 2026

📅 Planting Calendar

Direct Sow Outdoors Sunday, May 10, 2026

Pro Tip: Sow Cosmos directly outdoors around your last frost date when soil starts to warm.

🌿 Plant Details

Scientific Name Cosmos bipinnatus

Days to Maturity 60 days

Mature Height 24-60"

Spread 18"

Type Annual

☀️ Growing Requirements

☀️

Sun

Full Sun (6-8 hours)

💧

Water

Low-Moderate

↔️

Spacing

18" apart

🌱

Planting Depth

0.25" deep

Seeds typically germinate in 7-14 days

Ready to Plant Cosmos in Bozeman?

Get your seeds now so they're ready by Sunday, May 10, 2026.

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Growing Cosmos in Zone 5a

Cosmos (Cosmos bipinnatus) is a popular garden vegetable. In Bozeman, Montana, which is in USDA Hardiness Zone 5a, you should direct sow seeds around Sunday, May 10, 2026.

Your average last frost date is Sunday, May 10, 2026. Cosmos grows well when direct sown, as it doesn't transplant well or germinates quickly outdoors.