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When to Plant Soybeans in Milwaukee County, WI

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.

Milwaukee County, Wisconsin is in USDA Zone 5b. The average last spring frost is April 27 and the first fall frost is October 11, giving you a growing season of approximately 167 days.

At an elevation of 1,100 feet, Milwaukee County receives approximately 38.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 86ยฐF, providing good warmth for Soybeans during the growing season.

Milwaukee County, WI (Zone 5b) Moderate season
167 days
Last Spring Frost April 27
167 growing days
First Fall Frost October 11

Milwaukee County Soil Profile

Soil Type

Silt Loam

Soil pH

6.1-6.8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (26 days to spare)
Transplant: Apr 22 🍅 Harvest: Jul 15 – Sep 9
Recommended (50%) ✓ Fits season (27 days to spare)
Transplant: Apr 27 🍅 Harvest: Jul 20 – Sep 14
Safe Start (90%) ✓ Fits season (25 days to spare)
Transplant: May 13 🍅 Harvest: Aug 5 – Sep 30

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
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 55 gal / 100 sq ft
Soybeans needs ~1,450 GDD — county provides 2,421 GDD Excellent fit

Soybeans Planting Timeline โ€” Milwaukee County, WI

Soybeans Planting Calendar

Activity When Date Range
Direct Sow May 4 May 4 โ€“ May 25
Harvest July 27 Jul 27 โ€“ Sep 21

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 โ€”
July Harvest
August Harvest
September Harvest
October โ€”
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 5b

Growing Season

167 days

Growing Tips for Milwaukee 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 Milwaukee County, WI?

Milwaukee County is in Zone 5b with an average last frost of April 27. Plan your Soybeans planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Milwaukee County, WI?

Milwaukee County, Wisconsin is in USDA Hardiness Zone 5b. The average last spring frost is April 27 and first fall frost is October 11.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Milwaukee County gardeners in Zone 5b 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 Milwaukee County, WI. Local conditions may vary. Last updated: April 2026.