When to plant sweet potatoes in Maine

Plant out in Portland

May 17–May 31

Across Maine the window opens between May 16 and June 6. Find your city below; the dates follow each town's own average last frost.

Plant out 3–5 weeks after the last frost. Set out slips when the soil is warm, around 65°F. They need a long, hot season.

Sweet potatoes planting dates by city

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost

JanFebMarAprMayJunJulAugSepOctNovDec

PortlandMay 17–May 31

LewistonMay 16–May 30

BangorMay 25–Jun 8

South PortlandMay 17–May 31

AuburnMay 16–May 30

SanfordJun 6–Jun 20

BiddefordMay 30–Jun 13

WestbrookMay 17–May 31

SacoMay 17–May 31

When should I plant sweet potatoes in Maine?

In Portland, plant out from May 17 to May 31. Across Maine the window opens between May 16 and June 6, depending on the local last frost.

How is this date worked out?

Plant out 3–5 weeks after the last frost. Frost dates are NOAA 1991–2020 averages for the weather station nearest each city.