When to plant Spinach in Wyoming

In spring, from Apr 1 – June 15 in Casper to May 1 – June 15 in Laramie.

In fall, from May 15 – July 1 in Jackson to July 1 – Aug 15 in Gillette.

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

Spinach planting dates by place in Wyoming
PlaceSpringFall
CasperApr 1 – June 15July 1 – Aug 15
CheyenneApr 1 – June 15July 1 – Aug 15
CodyApr 1 – June 15July 1 – Aug 15
EvanstonMay 1 – June 15June 1 – July 15
GilletteApr 1 – June 15July 1 – Aug 15
Green RiverApr 10 – June 15June 1 – Aug 1
JacksonMay 1 – June 15May 15 – July 1
LaramieMay 1 – June 15May 15 – July 1
RivertonApr 1 – June 15June 1 – Aug 1
Rock SpringsApr 10 – June 15June 1 – Aug 1
SheridanApr 10 – June 15June 1 – Aug 1

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 spinach.