When to plant sweet potatoes in Montana

Sweet potatoes
Plant out in Billings
May 25–Jun 8

Across Montana the window opens between May 25 and July 4. Find your city below; the dates follow each town's own average last frost.

Plant out, Billings
May 25–Jun 8
Last sowing for a harvest
May 26
Last frost, Billings
May 4

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
BillingsMay 25–Jun 8
MissoulaMay 31–Jun 14
Great FallsMay 27–Jun 10
BozemanJun 16–Jun 30
Butte-Silver BowJul 4–Jul 18
HelenaMay 30–Jun 13
KalispellJun 21–Jul 5

In Bozeman, Butte-Silver Bow, Kalispell the frost-free season is shorter than sweet potatoes need. Start plants indoors and pick early varieties.

Questions

When should I plant sweet potatoes in Montana?

In Billings, plant out from May 25 to June 8. Across Montana the window opens between May 25 and July 4, 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.

Is the season long enough for sweet potatoes everywhere in Montana?

Not quite. In Bozeman, Butte-Silver Bow, Kalispell the frost-free season is shorter than the time sweet potatoes need to ripen. Start plants indoors and pick an early variety.

More for Montana

Sweet potatoes in other states

Frost dates for every city in Montana