When to Plant Corn in Iowa
Corn is a warm-season grass grown for its sweet ears, which are best eaten soon after harvest. It is wind-pollinated and must be planted in blocks for good kernel fill.
Iowa spans USDA hardiness zones 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 Corn planting dates based on your local frost dates.
Hover over a county to see details. Click to view planting guide.
Corn Planting Calendar for Iowa
▸ 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 | July 17 | Jul 17 – Sep 11 |
▸ 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 4 | Jul 4 – Aug 29 |
▸ 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 | June 27 | Jun 27 – Aug 22 |
Growing Tips for Iowa
Plant in blocks of at least 4 rows rather than single rows for proper pollination. Direct sow after soil reaches 60F. Side-dress with nitrogen when plants are knee-high.
Corn in Other States
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
Frequently Asked Questions
When should I plant Corn in Iowa?
Planting dates for Corn in Iowa depend on your USDA zone. Iowa spans zones 4b, 5a, 5b. Check the planting calendar above for your specific zone's frost dates and planting windows.
What zone is Iowa for planting?
Iowa contains USDA hardiness zones 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.