When to plant watermelon in Idaho
Idaho spans USDA zones 5a–7a, so the right time to plant watermelon shifts by weeks across the state. The window to transplant seedlings outdoors runs from about April 13 in Lewiston to May 24 in Garden City — below are local dates for 25 cities, each computed from its own frost dates.
| City | Zone | Last frost | First frost | Transplant out |
|---|---|---|---|---|
| Boise City | 7a | April 24 | October 21 | May 1 – May 8 |
| Meridian | 7a | April 24 | October 21 | May 1 – May 8 |
| Nampa | 7a | April 29 | October 13 | May 6 – May 13 |
| Idaho Falls | 5b | May 9 | October 1 | May 16 – May 23 |
| Caldwell | 7a | April 29 | October 13 | May 6 – May 13 |
| Pocatello | 6a | May 2 | October 11 | May 9 – May 16 |
| Coeur d'Alene | 6b | April 22 | October 18 | April 29 – May 6 |
| Twin Falls | 7a | April 30 | October 9 | May 7 – May 14 |
Watermelon in Idaho: FAQ
When can I plant watermelon in Idaho?
Across Idaho, the time to transplant watermelon spans roughly April 13 in Lewiston to May 24 in Garden City, each following that city's local frost dates.
Does the watermelon planting date vary across Idaho?
Yes. Idaho publishes 25 cities with their own frost dates, so the right watermelon 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 watermelon take to grow in Idaho?
Watermelon takes about 75–95 days to reach harvest once planted — check that this fits inside your city's frost-free season on its place page.
Never miss a window in your area
An email when it’s time to start seeds, transplant, and sow — timed to your frost dates. Double opt-in, one-click unsubscribe, no spam.