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When to Plant Soybeans in Sibley 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.

Sibley County, Minnesota is in USDA Zone 4a. The average last spring frost is April 30 and the first fall frost is October 4, giving you a growing season of approximately 157 days.

At an elevation of 1,364 feet, Sibley County receives approximately 40.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Soybeans to ensure they mature before fall.

Sibley County, MN (Zone 4a) Moderate season
157 days
Last Spring Frost April 30
157 growing days
First Fall Frost October 4

Sibley County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (17 days to spare)
Transplant: Apr 24 🍅 Harvest: Jul 17 – Sep 11
Recommended (50%) ✓ Fits season (17 days to spare)
Transplant: Apr 30 🍅 Harvest: Jul 23 – Sep 17
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
1.1″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Soybeans needs ~1,150 GDD — county provides 1,805 GDD Excellent fit

Soybeans Planting Timeline โ€” Sibley County, MN

Soybeans Planting Calendar

Activity When Date Range
Direct Sow May 14 May 14 โ€“ Jun 4
Harvest August 6 Aug 6 โ€“ Oct 1

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 4a

Growing Season

157 days

Growing Tips for Sibley 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 Sibley County, MN?

Sibley County is in Zone 4a with an average last frost of April 30. Plan your Soybeans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sibley County, MN?

Sibley County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is April 30 and first fall frost is October 4.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sibley County gardeners in Zone 4a 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 Sibley County, MN. Local conditions may vary. Last updated: April 2026.