When to plant Onion sets in Maine
In spring, from Mar 10 – Apr 1 in Auburn to Apr 20 – May 15 in Sanford.
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 |
|---|---|
| Auburn | Mar 10 – Apr 1 |
| Augusta | Mar 10 – Apr 10 |
| Bangor | Mar 10 – Apr 10 |
| Biddeford | Apr 10 – May 1 |
| Lewiston | Mar 10 – Apr 1 |
| Portland | Mar 10 – Apr 10 |
| Saco | Mar 10 – Apr 10 |
| Sanford | Apr 20 – May 15 |
| South Portland | Mar 10 – Apr 10 |
| Waterville | Mar 10 – Apr 10 |
| Westbrook | 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.