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When to plant Soybeans in Warren County, IA

Warren County sits in USDA Zone 5b. Plant Soybeans between May 3 (after last frost on April 26) and May 24.

When to Plant Soybeans in Warren County, IA

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.

Warren County, Iowa is in USDA Zone 5b. The average last spring frost is April 26 and the first fall frost is October 9, giving you a growing season of approximately 166 days.

At an elevation of 853 feet, Warren County receives approximately 30.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 87°F, providing good warmth for Soybeans during the growing season.

Warren County, IA (Zone 5b) Moderate season
166 days
Last Spring Frost April 26
166 growing days
First Fall Frost October 9

Warren County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Soybeans Planting Timeline — Warren County, IA

Soybeans Planting Calendar

Activity When Date Range
Direct Sow May 3 May 3 – May 24
Harvest July 26 Jul 26 – Sep 20

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

80–120 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5b

📆 Growing Season

166 days in Warren County

Growing Tips for Warren 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Soybeans in Warren County, IA?

Warren County is in Zone 5b with an average last frost of April 26. Plan your Soybeans planting based on this frost date — see the calendar above for exact timing.

What planting zone is Warren County, IA?

Warren County, Iowa is in USDA Hardiness Zone 5b. The average last spring frost is April 26 and first fall frost is October 9.

When should I plant Soybeans in Warren County, IA?

In Warren County, IA, plant Soybeans after the last frost (around April 26) and before the first frost (around October 9). Best results when soil holds above 50°F.

What growing zone is Warren County, IA for Soybeans?

Warren County sits in USDA Zone 5b. Soybeans grows reliably in zones 3a through 10b, so it's a good fit here.

Can Soybeans grow in Warren County's climate?

Yes — Soybeans grows well in Warren County's temperate climate. Warren County averages a 166-day frost-free season, with last frost around April 26 and first frost around October 9.

🌱

Your Warren County Garden Planner — Free

A 22-page printable planner built for Warren County (Zone 5b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Warren County, IA. Local conditions may vary. Last updated: June 2026.

Sources & credits

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