When to plant Potatoes in Montana

In spring, from Mar 20 – May 10 in Billings to May 15 – June 1 in Butte-Silver Bow (balance).

In fall, from May 1 – June 15 in Belgrade to May 15 – June 15 in Billings.

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

Potatoes planting dates by place in Montana
PlaceSpringFall
BelgradeMay 1 – June 15May 1 – June 15
BillingsMar 20 – May 10May 15 – June 15
BozemanMay 1 – June 15May 1 – June 15
Butte-Silver Bow (balance)May 15 – June 1May 1 – June 15
Great FallsApr 1 – June 1May 1 – June 15
HelenaApr 1 – June 1May 1 – June 15
KalispellMay 1 – June 15May 1 – June 15
MissoulaApr 1 – June 1May 1 – June 15

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 potatoes.