When to Plant Cauliflower in Wyoming
The diva of the brassica family. More temperamental than broccoli but worth the extra attention.
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 |
Cauliflower 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 Cauliflower in Wyoming
Cauliflower in Wyoming's Climate
Cauliflower is more demanding than broccoli — it needs steady 60-70°F temperatures during heading, which your unpredictable spring weather may not provide. Fall is the better season: start indoors in mid-June, transplant in mid-July, and let the gradual autumn cool-down produce tight, clean heads. Temperature swings cause buttoning (premature tiny heads).
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.
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 cauliflower — adjust your planting dates to match your specific region.
Growing Tips
Blanch white varieties by tying outer leaves over the head when it reaches 2 inches. Temperature swings cause buttoning.
Companion Planting
Plant cauliflower alongside these companions for better growth:
Keep cauliflower away from:
The Bottom Line
Last reviewed: March 29, 2026