When to plant butternut squash in Iowa
Iowa spans USDA zones 5a–6a, so the right time to plant butternut squash shifts by weeks across the state. The window to sow seed directly outdoors runs from about April 19 in Fort Madison to May 8 in Spencer — below are local dates for 42 cities, each computed from its own frost dates.
| City | Zone | Last frost | First frost | Direct sow |
|---|---|---|---|---|
| Des Moines | 5b | April 18 | October 20 | April 25 – May 9 |
| Cedar Rapids | 5b | April 27 | October 11 | May 4 – May 18 |
| Davenport | 5b | April 19 | October 22 | April 26 – May 10 |
| Sioux City | 5a | April 29 | October 7 | May 6 – May 20 |
| Iowa City | 5b | April 21 | October 18 | April 28 – May 12 |
| Ankeny | 5b | April 23 | October 15 | April 30 – May 14 |
| West Des Moines | 5b | April 18 | October 20 | April 25 – May 9 |
| Ames | 5b | April 26 | October 8 | May 3 – May 17 |
Butternut Squash in Iowa: FAQ
When can I plant butternut squash in Iowa?
Across Iowa, the time to direct-sow butternut squash spans roughly April 19 in Fort Madison to May 8 in Spencer, each following that city's local frost dates.
Does the butternut squash planting date vary across Iowa?
Yes. Iowa publishes 42 cities with their own frost dates, so the right butternut squash planting window shifts by weeks between the warmest and coldest parts of the state — use your city's page for the exact dates.
How long does butternut squash take to grow in Iowa?
Butternut Squash takes about 90–110 days to reach harvest once planted — check that this fits inside your city's frost-free season on its place page.
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