When to plant sunflowers in Wyoming

Sow outdoors in Cheyenne

May 14–Jun 4

Across Wyoming the window opens between May 10 and June 7. Find your city below; the dates follow each town's own average last frost.

Sow outdoors up to 3 weeks after the last frost. Sow every two weeks until midsummer for flowers through fall.

Sunflowers planting dates by city

Start indoorsPlant outSow outdoorsFall plantingAverage last and first frost

JanFebMarAprMayJunJulAugSepOctNovDec

CheyenneMay 14–Jun 4

CasperMay 10–May 31

GilletteMay 15–Jun 5

LaramieJun 7–Jun 28

Rock SpringsMay 24–Jun 14

SheridanMay 21–Jun 11

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

When should I plant sunflowers in Wyoming?

In Cheyenne, sow outdoors from May 14 to June 4. Across Wyoming the window opens between May 10 and June 7, depending on the local last frost.

How is this date worked out?

Sow outdoors up to 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 sunflowers everywhere in Wyoming?

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