When to plant Celery in Montana

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

In fall, from May 15 – July 1 in Belgrade to June 1 – July 5 in Missoula.

Dates are for setting out plants. USDA's earliest safe spring and latest safe fall planting dates, matched to each place's average frost dates.

Celery and celeriac planting dates by place in Montana
PlaceSpringFall
BelgradeMay 20 – June 1May 15 – July 1
BillingsApr 15 – May 1June 1 – July 15
BozemanMay 20 – June 1May 15 – July 1
Butte-Silver Bow (balance)June 1 – 15May 15 – June 15
Great FallsApr 20 – June 15June 1 – July 5
HelenaApr 20 – June 15June 1 – July 5
KalispellMay 20 – June 1May 15 – June 15
MissoulaApr 20 – June 15June 1 – July 5

Planting dates: USDA Home and Garden Bulletin No. 9 (1967), tables 4 and 5. Frost dates: NOAA U.S. Climate Normals 1991–2020. The full USDA table for celery and celeriac.