When to plant sweet corn in Idaho
Idaho spans USDA zones 5a–7a, so the right time to plant sweet corn shifts by weeks across the state. The window to sow seed directly outdoors runs from about April 6 in Lewiston to May 17 in Garden City — below are local dates for 25 cities, each computed from its own frost dates.
| City | Zone | Last frost | First frost | Direct sow |
|---|---|---|---|---|
| Boise City | 7a | April 24 | October 21 | April 24 – May 8 |
| Meridian | 7a | April 24 | October 21 | April 24 – May 8 |
| Nampa | 7a | April 29 | October 13 | April 29 – May 13 |
| Idaho Falls | 5b | May 9 | October 1 | May 9 – May 23 |
| Caldwell | 7a | April 29 | October 13 | April 29 – May 13 |
| Pocatello | 6a | May 2 | October 11 | May 2 – May 16 |
| Coeur d'Alene | 6b | April 22 | October 18 | April 22 – May 6 |
| Twin Falls | 7a | April 30 | October 9 | April 30 – May 14 |
Sweet Corn in Idaho: FAQ
When can I plant sweet corn in Idaho?
Across Idaho, the time to direct-sow sweet corn spans roughly April 6 in Lewiston to May 17 in Garden City, each following that city's local frost dates.
Does the sweet corn planting date vary across Idaho?
Yes. Idaho publishes 25 cities with their own frost dates, so the right sweet corn 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 sweet corn take to grow in Idaho?
Sweet Corn takes about 60–90 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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