When to plant Lettuce in Idaho

In spring, from Mar 15 – May 15 in Lewiston to May 1 – June 30 in Garden City.

In fall, from June 1 – Aug 1 in Ammon to Aug 15 – Oct 1 in Lewiston.

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

Leaf lettuce planting dates by place in Idaho
PlaceSpringFall
AmmonApr 15 – June 15June 1 – Aug 1
BlackfootApr 1 – June 1June 1 – Aug 1
Boise CityMar 20 – May 15July 15 – Sept 1
BurleyApr 15 – June 15June 1 – Aug 1
CaldwellApr 1 – June 1July 15 – Sept 1
ChubbuckMay 1 – June 30June 1 – Aug 1
Coeur d'AleneMar 20 – May 15July 15 – Sept 1
EagleApr 1 – June 1July 15 – Sept 1
Garden CityMay 1 – June 30July 15 – Sept 1
HaydenMar 20 – May 15July 15 – Sept 1
Idaho FallsApr 15 – June 15June 1 – Aug 1
JeromeApr 1 – June 1July 15 – Sept 1
KunaMar 20 – May 15July 15 – Sept 1
LewistonMar 15 – May 15Aug 15 – Oct 1
MeridianMar 20 – May 15July 15 – Sept 1
MiddletonApr 1 – June 1July 15 – Sept 1
MoscowApr 1 – June 1June 1 – Aug 1
Mountain HomeApr 1 – June 1July 15 – Sept 1
NampaApr 1 – June 1July 15 – Sept 1
PocatelloApr 1 – June 1July 15 – Sept 1
Post FallsMar 20 – May 15July 15 – Sept 1
RathdrumMar 20 – May 15July 15 – Sept 1
RexburgApr 15 – June 15June 1 – Aug 1
SandpointApr 15 – June 15June 1 – Aug 1
StarApr 1 – June 1July 15 – Sept 1
Twin FallsApr 1 – June 1July 15 – Sept 1

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 leaf lettuce.