When to plant Sweet potatoes in Maine

In spring, from May 10 – June 10 in Auburn to May 20 – June 10 in Westbrook.

In fall, from May 20 – June 10 in Portland to June 1 – 15 in Lewiston.

USDA's earliest safe spring and latest safe fall planting dates, matched to each place's average frost dates.

Sweet potatoes planting dates by place in Maine
PlaceSpringFall
AuburnMay 10 – June 10June 1 – 15
AugustaMay 20 – June 10June 1 – 15
BangorMay 20 – June 10Not listed
BiddefordNot listedNot listed
LewistonMay 10 – June 10June 1 – 15
PortlandMay 20 – June 10May 20 – June 10
SacoMay 20 – June 10May 20 – June 10
SanfordNot listedNot listed
South PortlandMay 20 – June 10May 20 – June 10
WatervilleMay 20 – June 10May 20 – June 10
WestbrookMay 20 – June 10May 20 – June 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 sweet potatoes.