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
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
Western Wyoming (Zones 3a, 3b, 4a)
Average last frost: May 25 - Jun 15 · Average first frost: Aug 25 - Sep 15
Southern Wyoming (Zones 4b, 5a, 5b)
Average last frost: May 15 - Jun 1 · Average first frost: Sep 5 - Sep 20
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:
The Bottom Line
Last reviewed: March 29, 2026