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When to Plant Soybeans in Wisconsin

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.

Wisconsin spans USDA hardiness zones 3b, 4a, 4b, 5a, 5b (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.

Find Your County

Click your county for exact Soybeans planting dates based on your local frost dates.

Soybeans Planting Calendar for Wisconsin

Zone 3b ~135 day growing season · Full guide →

Last frost: May 10 · First frost: September 22 · 135 day season

Activity When Date Range
Direct Sow May 24 May 24 – Jun 14
Harvest August 16 Aug 16 – Sep 27
Zone 4a ~145 day growing season · Full guide →

Last frost: May 6 · First frost: September 28 · 145 day season

Activity When Date Range
Direct Sow May 20 May 20 – Jun 10
Harvest August 12 Aug 12 – Oct 7
Zone 4b ~155 day growing season · Full guide →

Last frost: May 1 · First frost: October 3 · 155 day season

Activity When Date Range
Direct Sow May 15 May 15 – Jun 5
Harvest August 7 Aug 7 – Oct 2
Zone 5a ~166 day growing season · Full guide →

Last frost: April 25 · First frost: October 8 · 166 day season

Activity When Date Range
Direct Sow May 2 May 2 – May 23
Harvest July 25 Jul 25 – Sep 19
Zone 5b ~178 day growing season · Full guide →

Last frost: April 18 · First frost: October 13 · 178 day season

Activity When Date Range
Direct Sow April 25 Apr 25 – May 16
Harvest July 18 Jul 18 – Sep 12

Growing Tips for Wisconsin

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.

Frequently Asked Questions

When should I plant Soybeans in Wisconsin?

Planting dates for Soybeans in Wisconsin depend on your USDA zone. Wisconsin spans zones 3b, 4a, 4b, 5a, 5b. Check the planting calendar above for your specific zone's frost dates and planting windows.

What zone is Wisconsin for planting?

Wisconsin contains USDA hardiness zones 3b, 4a, 4b, 5a, 5b. Your specific zone depends on your location within the state — northern and higher-elevation areas are in colder zones, while southern and coastal areas are warmer.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Last updated: April 2026.