When to plant sweet potato in South Dakota
South Dakota spans USDA zones 4a–5b, so the right time to plant sweet potato shifts by weeks across the state. The window to transplant seedlings outdoors runs from about May 17 in Sioux Falls to June 2 in Spearfish — below are local dates for 13 cities, each computed from its own frost dates.
| City | Zone | Last frost | First frost | Transplant out |
|---|---|---|---|---|
| Sioux Falls | 5a | April 26 | October 13 | May 17 – May 31 |
| Rapid City | 5b | May 3 | October 8 | May 24 – June 7 |
| Aberdeen | 4a | May 8 | September 29 | May 29 – June 12 |
| Brookings | 4b | May 6 | October 1 | May 27 – June 10 |
| Watertown | 4b | May 7 | September 30 | May 28 – June 11 |
| Mitchell | 5a | May 2 | October 6 | May 23 – June 6 |
| Yankton | 5a | April 27 | October 11 | May 18 – June 1 |
| Huron | 4b | May 6 | October 2 | May 27 – June 10 |
Sweet Potato in South Dakota: FAQ
When can I plant sweet potato in South Dakota?
Across South Dakota, the time to transplant sweet potato spans roughly May 17 in Sioux Falls to June 2 in Spearfish, each following that city's local frost dates.
Does the sweet potato planting date vary across South Dakota?
Yes. South Dakota publishes 13 cities with their own frost dates, so the right sweet potato 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 potato take to grow in South Dakota?
Sweet Potato takes about 90–120 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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