When to plant Onions in Maine
In spring, from Mar 15 – Apr 10 in Auburn to Apr 20 – May 15 in Sanford.
In fall: USDA's 1967 table lists onion plants as generally spring-planted in every place here. Newer advice from your state's extension service may differ.
Dates are for setting out plants. USDA's earliest safe spring and latest safe fall planting dates, matched to each place's average frost dates.
| Place | Spring |
|---|---|
| Auburn | Mar 15 – Apr 10 |
| Augusta | Apr 1 – May 1 |
| Bangor | Apr 1 – May 1 |
| Biddeford | Apr 10 – May 1 |
| Lewiston | Mar 15 – Apr 10 |
| Portland | Apr 1 – May 1 |
| Saco | Apr 1 – May 1 |
| Sanford | Apr 20 – May 15 |
| South Portland | Apr 1 – May 1 |
| Waterville | Apr 1 – May 1 |
| Westbrook | Apr 1 – May 1 |
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 plants.