When to plant Carrots in Montana

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

In fall, from May 15 – June 15 in Butte-Silver Bow (balance) to June 1 – July 10 in Missoula.

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

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