When to plant Sweet corn in Maine

In spring, from Apr 25 – June 15 in Auburn to May 15 – June 1 in Sanford.

In fall, June 1 – July 20.

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

Sweet corn planting dates by place in Maine
PlaceSpringFall
AuburnApr 25 – June 15June 1 – July 20
AugustaMay 10 – June 15June 1 – July 20
BangorMay 10 – June 15June 1 – July 1
BiddefordMay 10 – June 1June 1 – July 1
LewistonApr 25 – June 15June 1 – July 20
PortlandMay 10 – June 15June 1 – July 10
SacoMay 10 – June 15June 1 – July 10
SanfordMay 15 – June 1June 1 – July 1
South PortlandMay 10 – June 15June 1 – July 10
WatervilleMay 10 – June 15June 1 – July 10
WestbrookMay 10 – June 15June 1 – July 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 corn.