FrostCal

When to Plant Sweet Potatoes in Montana

In a typical Montana location, plant outdoors May 28 – Jun 11. Across the state, the outdoor planting window starts as early as May 19 in Laurel and as late as Jun 27 in Butte.

Method Plant out (slips, crowns, or tubers)
Days to maturity 90–120 days

Set out slips 2-4 weeks after last frost once soil is thoroughly warm (65F+); very frost/cold sensitive.

Sweet Potatoes Planting Dates by City

CityPlant outdoors
BillingsMay 24 – Jun 7
MissoulaMay 24 – Jun 7
Great FallsMay 20 – Jun 3
BozemanJun 9 – Jun 23
ButteJun 27 – Jul 11
HelenaMay 23 – Jun 6
KalispellJun 14 – Jun 28
HavreMay 29 – Jun 12
AnacondaJun 15 – Jun 29
Miles CityMay 22 – Jun 5
Helena Valley SoutheastMay 23 – Jun 6
BelgradeJun 9 – Jun 23
Helena Valley West CentralMay 23 – Jun 6
EvergreenJun 14 – Jun 28
LivingstonJun 10 – Jun 24
WhitefishMay 30 – Jun 13
LaurelMay 19 – Jun 2
SidneyMay 25 – Jun 8
LockwoodMay 24 – Jun 7
LewistownMay 28 – Jun 11

Showing the 20 most populous of 20 Montana cities. Dates are estimates from each city's NOAA frost normals and university extension timing guidelines. See all Montana cities.

Frequently Asked Questions

When should I plant sweet potatoes in Montana?

In a typical Montana location, plant outdoors May 28 – Jun 11. Across the state, the outdoor planting window starts as early as May 19 in Laurel and as late as Jun 27 in Butte.

When is the last frost in Montana?

The average last spring frost in Montana ranges from May 5 in Laurel to June 13 in Butte, based on NOAA 1991–2020 climate normals.

How long do sweet potatoes take to grow?

Sweet Potatoes typically take 90–120 days from planting to harvest. Set out slips 2-4 weeks after last frost once soil is thoroughly warm (65F+); very frost/cold sensitive.

Other Crops in Montana

When to plant sweet potatoes in other states

Related Guides