2026 Planting Guide
Spring cropWhen to Plant Corn (Maize) in Iowa
Complete guide to growing corn (maize) 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 corn (maize) growing season in Iowa. Red diamond markers indicate frost date boundaries.
Quick Facts
Min. Soil Temp
50°F (10°C) minimum
Growing Period
100-120 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 corn (maize) in Iowa.
January - March
Off-seasonCover crop planting, soil testing, equipment maintenance, and planning for next season.
April - May
PlantPrepare soil, apply starter fertilizer, and sow seeds at recommended depth and spacing.
June - August
Grow & MonitorIrrigate as needed, scout for pests, apply side-dress fertilizer, and manage weeds.
September - November
HarvestCheck maturity indicators, schedule equipment, harvest at optimal moisture content.
December
Off-seasonCover crop planting, soil testing, equipment maintenance, and planning for next season.
Best Corn (Maize) Varieties for Iowa
These varieties have proven performance in Iowa's climate and soil conditions. Always source certified seed from reputable dealers.
| # | Variety | Best For |
|---|---|---|
| 1 | DeKalb DKC64-69 | Iowa climate |
| 2 | Pioneer P1185AM | Iowa climate |
| 3 | Channel 209-53VT2P | Iowa climate |
| 4 | Beck Hybrids 6175AM | Iowa climate |
Growing Tips for Iowa
Region-specific advice from agricultural extension services and experienced Iowa farmers.
Plant when soil temp is consistently above 50°F at 2-inch depth
Target 32,000-36,000 seeds/acre for optimal yield
Apply nitrogen split: 1/3 at planting, 2/3 at V6 stage
Scout for corn rootworm starting in June
Pest & Disease Watch
Monitor for these threats throughout the growing season. Integrated Pest Management (IPM) is recommended.
Corn borers
Scout regularly and use integrated pest management
Corn rootworm
Scout regularly and use integrated pest management
Fall armyworm
Scout regularly and use integrated pest management
Aphids
Scout regularly and use integrated pest management
Cutworms
Scout regularly and use integrated pest management
Companion Planting
These plants grow well alongside corn (maize), improving pest control, pollination, and nutrient availability.
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 corn (maize) in Iowa?
The optimal planting window for corn (maize) in Iowa is April 20 to May 20. Soil temperature should reach at least 50°F (10°C) minimum before planting. The total growing period is 100-120 days.
What varieties of corn (maize) grow best in Iowa?
The best varieties for Iowa include DeKalb DKC64-69, Pioneer P1185AM, Channel 209-53VT2P, Beck Hybrids 6175AM. These varieties are adapted to local climate and soil conditions and have proven performance records.
When can I harvest corn (maize) in Iowa?
The harvest window for corn (maize) in Iowa is typically September 25 to November 5. The crop takes 100-120 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.