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When to Plant Soybeans in Freeborn County, MN

Soybeans (edamame) are a high-protein legume that fixes nitrogen in the soil. Fresh green soybeans harvested at the edamame stage are a nutritious snack.

Freeborn County, Minnesota is in USDA Zone 4b. The average last spring frost is May 1 and the first fall frost is October 7, giving you a growing season of approximately 159 days.

At an elevation of 1,253 feet, Freeborn County receives approximately 34.7 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Soybeans to ensure they mature before fall.

Freeborn County, MN (Zone 4b) Moderate season
159 days
Last Spring Frost May 1
159 growing days
First Fall Frost October 7

Freeborn County Soil Profile

Soil Type

Silt Loam

Soil pH

5.8-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (20 days to spare)
Transplant: Apr 24 🍅 Harvest: Jul 17 – Sep 11
Recommended (50%) ✓ Fits season (19 days to spare)
Transplant: May 1 🍅 Harvest: Jul 24 – Sep 18
Safe Start (90%) ✓ Fits season (14 days to spare)
Transplant: May 15 🍅 Harvest: Aug 7 – Oct 2

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.9″/week
You supply
0.1″/week
Watering frequency Only during dry spells
Season total 118 gal / 100 sq ft
Soybeans needs ~1,300 GDD — county provides 2,067 GDD Excellent fit

Soybeans Planting Timeline โ€” Freeborn County, MN

Soybeans Planting Calendar

Activity When Date Range
Direct Sow May 15 May 15 โ€“ Jun 5
Harvest August 7 Aug 7 โ€“ Oct 2

Plant 1" deep ยท 15" apart ยท Rows 24" apart

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March โ€”
April โ€”
May Direct Sow
June Direct Sow
July โ€”
August Harvest
September Harvest
October Harvest
November โ€”
December โ€”

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

80โ€“120 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 4b

Growing Season

159 days

Growing Tips for Freeborn County

Direct sow after soil warms to 60F. Plant in blocks rather than rows for better pollination. Harvest for edamame when pods are plump and bright green.

Companion Planting

Good Companions

Avoid Planting Near

  • Onion
  • Garlic

Level Up Your Garden

Frequently Asked Questions

When should I plant Soybeans in Freeborn County, MN?

Freeborn County is in Zone 4b with an average last frost of May 1. Plan your Soybeans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Freeborn County, MN?

Freeborn County, Minnesota is in USDA Hardiness Zone 4b. The average last spring frost is May 1 and first fall frost is October 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Freeborn County gardeners in Zone 4b organize planting dates, track what's growing, and never miss a planting window.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Freeborn County, MN. Local conditions may vary. Last updated: April 2026.