When to Plant Onion in Worthing, South Dakota (57077)

Location

Worthing, South Dakota

ZIP Code

57077

USDA Zone

Last Frost

Sunday, May 10, 2026

📅 Planting Calendar

Start Seeds Indoors Sunday, March 15, 2026

Transplant Outdoors Sunday, May 24, 2026

Pro Tip: Start Onion seeds indoors 8 weeks before your last frost date, then transplant outdoors around Sunday, May 24, 2026.

🌿 Plant Details

Scientific Name Allium cepa

Days to Maturity 100 days

Mature Height 12-18"

Spread 4"

Type Bulb

Fruit Size Medium (2-4 inch bulb)

☀️ Growing Requirements

☀️

Sun

Full Sun (6+ hours)

💧

Water

Moderate

↔️

Spacing

4" apart

🌱

Planting Depth

0.5" deep

Seeds typically germinate in 7-10 days

Ready to Plant Onion in Worthing?

Get your seeds now so they're ready by Sunday, March 15, 2026.

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🤝 Good Companions

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⚠️ Avoid Planting Near

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Other Plants for Worthing

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Growing Onion in Zone 5a

Onion (Allium cepa) is a popular garden vegetable. In Worthing, South Dakota, which is in USDA Hardiness Zone 5a, you should start seeds indoors around Sunday, March 15, 2026.

Your average last frost date is Sunday, May 10, 2026. Plan to transplant your Onion seedlings outdoors around Sunday, May 24, 2026, about 2 weeks after your last frost date.