When to plant Chinese cabbage in Wyoming

In spring, from Apr 1 – May 15 in Casper to May 20 – June 1 in Laramie.

In fall, from May 15 – June 15 in Evanston to June 1 – July 1 in Sheridan.

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

Chinese cabbage planting dates by place in Wyoming
PlaceSpringFall
CasperApr 1 – May 15June 1 – July 15
CheyenneApr 1 – May 15June 1 – July 15
CodyApr 1 – May 15June 1 – July 15
EvanstonMay 20 – June 1May 15 – June 15
GilletteApr 1 – May 15June 1 – July 15
Green RiverMay 1 – June 15June 1 – July 1
JacksonMay 20 – June 1May 15 – June 15
LaramieMay 20 – June 1May 15 – June 15
RivertonApr 1 – May 15June 1 – July 1
Rock SpringsMay 1 – June 15June 1 – July 1
SheridanMay 1 – June 15June 1 – July 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 chinese cabbage.