When to plant tomatoes in Wyoming

Plant out in Cheyenne

May 21–Jun 4

Across Wyoming the window opens between May 17 and June 14. Find your city below; the dates follow each town's own average last frost.

Start indoors, Cheyenne: Mar 19–Apr 2
Plant out, Cheyenne: May 21–Jun 4
Last sowing for a harvest: Jun 24
Last frost, Cheyenne: May 14

Start seeds indoors 6–8 weeks before the last frost; plant out 1–3 weeks after the last frost. Wait for nights that stay above 50°F. A cold snap after transplanting stalls tomatoes for weeks.

Tomatoes planting dates by city

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost

JanFebMarAprMayJunJulAugSepOctNovDec

CheyenneMay 21–Jun 4

CasperMay 17–May 31

GilletteMay 22–Jun 5

LaramieJun 14–Jun 28

Rock SpringsMay 31–Jun 14

SheridanMay 28–Jun 11

In Laramie the frost-free season is shorter than tomatoes need. Start plants indoors and pick early varieties.

Questions

When should I plant tomatoes in Wyoming?

In Cheyenne, plant out from May 21 to June 4. Across Wyoming the window opens between May 17 and June 14, depending on the local last frost.

How is this date worked out?

Start seeds indoors 6–8 weeks before the last frost; plant out 1–3 weeks after the last frost. Frost dates are NOAA 1991–2020 averages for the weather station nearest each city.

Is the season long enough for tomatoes everywhere in Wyoming?

Not quite. In Laramie the frost-free season is shorter than the time tomatoes need to ripen. Start plants indoors and pick an early variety.