When to plant onions in Wyoming

Onions
Plant out in Cheyenne
Apr 2–Apr 23

Across Wyoming the window opens between March 29 and April 26. Find your city below; the dates follow each town's own average last frost.

Start indoors, Cheyenne
Feb 19–Mar 19
Plant out, Cheyenne
Apr 2–Apr 23
Last frost, Cheyenne
May 14

Start seeds indoors 8–12 weeks before the last frost; plant out 3–6 weeks before the last frost. Northern gardens need long-day varieties and southern gardens need short-day ones. A wrong pick gives small bulbs.

Onions planting dates by city

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost
JanFebMarAprMayJunJulAugSepOctNovDec
CheyenneApr 2–Apr 23
CasperMar 29–Apr 19
GilletteApr 3–Apr 24
LaramieApr 26–May 17
Rock SpringsApr 12–May 3
SheridanApr 9–Apr 30

Questions

When should I plant onions in Wyoming?

In Cheyenne, plant out from April 2 to April 23. Across Wyoming the window opens between March 29 and April 26, depending on the local last frost.

How is this date worked out?

Start seeds indoors 8–12 weeks before the last frost; plant out 3–6 weeks before the last frost. Frost dates are NOAA 1991–2020 averages for the weather station nearest each city.

More for Wyoming

Onions in other states

Frost dates for every city in Wyoming