2026 Planting Guide

Spring crop

When to Plant Soybeans in Iowa

Plant May 1June 5Harvest September 25November 1100-140 days growing period

Complete guide to growing soybeans in Iowa with optimal planting dates, recommended varieties, soil requirements, pest management, and harvest timing. Data sourced from USDA and state extension services.

Monthly Planting Calendar

Visual overview of the soybeans growing season in Iowa. Red diamond markers indicate frost date boundaries.

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Plant
Plant
Grow
Grow
Harvest
Harvest
Harvest
Plant: May 1 - June 5GrowHarvest: September 25 - November 1Frost dates

Quick Facts

Min. Soil Temp

50°F (10°C) minimum

32F50F65F80F

Growing Period

100-140 days

From planting to harvest

Last Spring Frost

April 25

Wait until after this date

First Fall Frost

October 8

Harvest before this date

Monthly Task Timeline

Month-by-month guide for managing soybeans in Iowa.

January - April

Off-season

Cover crop planting, soil testing, equipment maintenance, and planning for next season.

May - June

Plant

Prepare soil, apply starter fertilizer, and sow seeds at recommended depth and spacing.

July - August

Grow & Monitor

Irrigate as needed, scout for pests, apply side-dress fertilizer, and manage weeds.

September - November

Harvest

Check maturity indicators, schedule equipment, harvest at optimal moisture content.

December

Off-season

Cover crop planting, soil testing, equipment maintenance, and planning for next season.

Best Soybeans Varieties for Iowa

These varieties have proven performance in Iowa's climate and soil conditions. Always source certified seed from reputable dealers.

#VarietyBest For
1Asgrow AG27X0Iowa climate
2Pioneer P25A70XIowa climate
3Channel 2618R2XIowa climate
4Beck 274NXIowa climate

Growing Tips for Iowa

Region-specific advice from agricultural extension services and experienced Iowa farmers.

1

Inoculate seed if field has not grown soybeans in 3+ years

2

Plant 130,000-140,000 seeds/acre in 15-inch rows

3

Early planting (May 1-10) maximizes yield potential in Iowa

4

Scout for soybean cyst nematode — rotate resistant varieties

Pest & Disease Watch

Monitor for these threats throughout the growing season. Integrated Pest Management (IPM) is recommended.

Soybean aphid

Scout regularly and use integrated pest management

Bean leaf beetle

Scout regularly and use integrated pest management

Spider mites

Scout regularly and use integrated pest management

Stink bugs

Scout regularly and use integrated pest management

Soybean cyst nematode

Scout regularly and use integrated pest management

Companion Planting

These plants grow well alongside soybeans, improving pest control, pollination, and nutrient availability.

Corn
Sorghum
Wheat (rotation)
Clover

Frost Dates

Last Spring Frost

April 25

Wait until after this date before planting frost-sensitive crops outdoors.

First Fall Frost

October 8

Plan to complete harvest of warm-season crops before this date arrives.

Frequently Asked Questions

When is the best time to plant soybeans in Iowa?

The optimal planting window for soybeans in Iowa is May 1 to June 5. Soil temperature should reach at least 50°F (10°C) minimum before planting. The total growing period is 100-140 days.

What varieties of soybeans grow best in Iowa?

The best varieties for Iowa include Asgrow AG27X0, Pioneer P25A70X, Channel 2618R2X, Beck 274NX. These varieties are adapted to local climate and soil conditions and have proven performance records.

When can I harvest soybeans in Iowa?

The harvest window for soybeans in Iowa is typically September 25 to November 1. The crop takes 100-140 days from planting to reach maturity.

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Data Sources

Data sourced from USDA NASS Crop Planting Dates, Iowa Cooperative Extension Service, and NOAA frost date records. Last updated: March 2026.

Planting dates are averages and may vary by county, elevation, and local microclimate. Always consult your local extension office for the most precise recommendations.