When to plant Onion sets in South Dakota
In spring, from Mar 10 – Apr 10 in Brandon to Apr 10 – May 1 in Watertown.
In fall: USDA's 1967 table lists onion sets as generally spring-planted in every place here. Newer advice from your state's extension service may differ.
USDA's earliest safe spring and latest safe fall planting dates, matched to each place's average frost dates.
| Place | Spring |
|---|---|
| Aberdeen | Apr 10 – May 1 |
| Box Elder | Apr 10 – May 1 |
| Brandon | Mar 10 – Apr 10 |
| Brookings | Apr 10 – May 1 |
| Harrisburg | Mar 10 – Apr 10 |
| Huron | Apr 10 – May 1 |
| Mitchell | Mar 10 – Apr 10 |
| Pierre | Apr 10 – May 1 |
| Rapid City | Mar 10 – Apr 10 |
| Sioux Falls | Mar 10 – Apr 10 |
| Spearfish | Apr 10 – May 1 |
| Vermillion | Mar 10 – Apr 10 |
| Watertown | Apr 10 – May 1 |
| Yankton | Mar 10 – Apr 10 |
Planting dates: USDA Home and Garden Bulletin No. 9 (1967), tables 4 and 5. Frost dates: NOAA U.S. Climate Normals 1991–2020. “—” means the place's frost date is outside the table. The full USDA table for onion sets.