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When to Plant Sweet Potato in Simms, Montana (59477)

Location

Simms, Montana

ZIP Code

59477

USDA Zone

4b

Last Frost

Tuesday, May 5, 2026

📅 Planting Calendar

Direct Sow Outdoors Tuesday, May 5, 2026

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

🌿 Plant Details

Scientific Name Ipomoea batatas
Days to Maturity 100 days
Mature Height 12-18"
Spread 36"
Type Vine
Fruit Size Medium-Large (6-12 oz per root)

☀️ Growing Requirements

☀️

Sun

Full Sun (8+ hours)

💧

Water

Moderate (reduce as harvest approaches)

↔️

Spacing

12" apart

🌱

Planting Depth

4" deep

Seeds typically germinate in 14-21 days

Ready to Plant Sweet Potato in Simms?

Get your seeds now so they're ready by Tuesday, May 5, 2026.

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🤝 Good Companions

OkraDillThyme

⚠️ Avoid Planting Near

SquashSunflower

Other Plants for Simms

Growing Sweet Potato in Zone 4b

Sweet Potato (Ipomoea batatas) is a popular garden vegetable. In Simms, Montana, which is in USDA Hardiness Zone 4b, you should direct sow seeds around Tuesday, May 5, 2026.

Your average last frost date is Tuesday, May 5, 2026. Sweet Potato grows well when direct sown, as it doesn't transplant well or germinates quickly outdoors.