🌱 MyLocalPlanting

When to Plant Onion in Medford, Minnesota (55049)

Location

Medford, Minnesota

ZIP Code

55049

USDA Zone

4b

Last Frost

Tuesday, May 5, 2026

📅 Planting Calendar

Start Seeds Indoors Tuesday, March 10, 2026
Transplant Outdoors Tuesday, May 19, 2026

Pro Tip: Start Onion seeds indoors 8 weeks before your last frost date for best results.

🌿 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

🤝 Good Companions

CarrotBeetLettuceTomatoBrassicas

⚠️ Avoid Planting Near

BeanPeaAsparagus

Other Plants for Medford

Growing Onion in Zone 4b

Onion (Allium cepa) is a popular garden vegetable. In Medford, Minnesota, which is in USDA Hardiness Zone 4b, you should start seeds indoors around Tuesday, March 10, 2026.

Your average last frost date is Tuesday, May 5, 2026. Plan to transplant your Onion seedlings outdoors around Tuesday, May 19, 2026, about 2 weeks after your last frost date.