When to Plant Butternut Squash in Iowa
Butternut squash is a popular winter squash with a long neck, small seed cavity, and sweet, nutty orange flesh. It stores exceptionally well for months.
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 Butternut Squash planting dates based on your local frost dates.
Hover over a county to see details. Click to view planting guide.
Butternut Squash 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 |
|---|---|---|
| Start Indoors | March 20 | Mar 20 – Apr 3 |
| Transplant Outdoors | May 22 | May 22 – Jun 5 |
| Direct Sow | May 15 | May 15 – Jun 5 |
| Harvest | August 21 | Aug 21 – Sep 25 |
▸ Zone 5a ~166 day growing season · Full guide →
Last frost: April 25 · First frost: October 8 · 166 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 21 | Mar 21 – Apr 4 |
| Transplant Outdoors | May 9 | May 9 – May 23 |
| Direct Sow | May 2 | May 2 – May 23 |
| Harvest | August 8 | Aug 8 – Sep 12 |
▸ Zone 5b ~178 day growing season · Full guide →
Last frost: April 18 · First frost: October 13 · 178 day season
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | March 14 | Mar 14 – Mar 28 |
| Transplant Outdoors | May 2 | May 2 – May 16 |
| Direct Sow | April 25 | Apr 25 – May 16 |
| Harvest | August 1 | Aug 1 – Sep 5 |
Growing Tips for Iowa
Start seeds indoors 3 weeks early or direct sow after frost. Allow 6-8 feet for sprawling vines. Harvest when the skin is hard and uniformly tan. Cure in the sun for 10 days.
Butternut Squash 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 Butternut Squash in Iowa?
Planting dates for Butternut Squash 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.