When to Plant Basil in Wyoming
The king of herbs. Basil and tomatoes are best friends in the garden and in the kitchen.
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 |
Basil 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 Basil in Wyoming
Basil in Wyoming's Climate
Basil needs warmth and dies at the first hint of frost. Start seeds indoors 6 weeks before your last frost and don't transplant until nights stay above 55°F — often 2-3 weeks after your official last frost date. Your growing window may be only 10-14 weeks, so make them count: pinch flower buds aggressively and harvest often. Consider growing in containers you can move indoors during unexpected cold snaps.
Soil Considerations for Wyoming
Alkaline, thin soils. Dry climate means little organic matter naturally. Wind erosion a significant challenge. Heavy amendment needed. Make sure soil has warmed to at least 60°F before planting basil outside.
Wyoming Climate & Growing Season
Short growing season. Very windy — wind protection essential for gardens. Low humidity. Cool nights even in summer at elevation. Basil cannot tolerate any frost, so wait until all frost danger has passed before transplanting outside. Watch local forecasts carefully in spring.
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 basil — transplant timing shifts by several weeks across the state.
Growing Tips
Pinch off flower buds to keep leaves producing. Harvest from the top down, cutting just above a leaf pair. Succession plant for season-long supply.
Companion Planting
Plant basil alongside these companions for better growth:
Keep basil away from:
The Bottom Line
Last reviewed: March 29, 2026