Perennial Flower

When to Plant Daylilies in Wyoming

Nearly indestructible perennials with stunning trumpet-shaped blooms. Each flower lasts just one day, but the show goes on for weeks.

The Short Answer

In Wyoming, plant daylilies based on your regional frost dates. Eastern Wyoming has a last frost around May 10 - May 30, while Southern Wyoming sees frost end around May 15 - Jun 1. Short growing season. Very windy — wind protection essential for gardens. Low humidity. Cool nights even in summer at...

Wyoming Frost Dates

Your planting dates depend on which part of Wyoming you're in. Here are the frost date ranges by region:

Region Zones Last Frost (Spring) First Frost (Fall)
Eastern Wyoming 4a, 4b, 5a May 10 - May 30 Sep 10 - Sep 25
Western Wyoming 3a, 3b, 4a May 25 - Jun 15 Aug 25 - Sep 15
Southern Wyoming 4b, 5a, 5b May 15 - Jun 1 Sep 5 - Sep 20

Daylilies Planting Schedule for Wyoming

Eastern Wyoming (Zones 4a, 4b, 5a)

Average last frost: May 10 - May 30 · Average first frost: Sep 10 - Sep 25

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0 wks after frost

Western Wyoming (Zones 3a, 3b, 4a)

Average last frost: May 25 - Jun 15 · Average first frost: Aug 25 - Sep 15

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0 wks after frost

Southern Wyoming (Zones 4b, 5a, 5b)

Average last frost: May 15 - Jun 1 · Average first frost: Sep 5 - Sep 20

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0 wks after frost

Growing Daylilies in Wyoming

Daylilies in Wyoming's Climate

Daylilies are bombproof perennials for cold climates. They survive harsh winters, tolerate poor soil, and bloom reliably through moderate summers. Choose dormant varieties for the coldest zones — they go completely dormant in winter and emerge vigorously each spring. Stella de Oro reblooms from June through frost.

Soil Considerations for Wyoming

Alkaline, thin soils. Dry climate means little organic matter naturally. Wind erosion a significant challenge. Heavy amendment needed.

Wyoming Climate & Growing Season

Short growing season. Very windy — wind protection essential for gardens. Low humidity. Cool nights even in summer at elevation. Daylilies can handle frost well, which is an advantage in Wyoming's climate. You can push planting dates earlier in spring and extend into fall.

Growing season length varies across Wyoming: Eastern Wyoming (4a, 4b, 5a) has a last frost around May 10 - May 30, while Southern Wyoming (4b, 5a, 5b) sees frost end around May 15 - Jun 1. This difference matters for daylilies — adjust your planting dates to match your specific region.

Growing Tips

Plant bare-root or divisions in spring or fall. Divide clumps every 3-4 years to maintain vigor. Deadhead to keep gardens tidy.

Companion Planting

Plant daylilies alongside these companions for better growth:

Coneflowers Black Eyed Susans

The Bottom Line

Daylilies can be grown successfully across Wyoming, but your exact planting dates depend on which region you're in. Eastern Wyoming gardeners should plan around a May 10 - May 30 last frost, while those in Southern Wyoming can typically plant later. For exact dates based on your zip code, use our free planting date finder.
Note: All dates are based on NOAA 30-year Climate Normals and represent historical averages, not predictions for any specific year. Always check your local weather forecast before planting frost-sensitive crops. Learn about our data sources.

Last reviewed: March 29, 2026

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