When to Plant Kale in Montana
The toughest green in the garden. Kale laughs at frost and actually tastes sweeter after a cold snap.
The Short Answer
Montana Frost Dates
Your planting dates depend on which part of Montana you're in. Here are the frost date ranges by region:
| Region | Zones | Last Frost (Spring) | First Frost (Fall) |
|---|---|---|---|
| Western Montana | 4b, 5a, 5b | May 10 - May 30 | Sep 10 - Sep 30 |
| Central Montana | 3b, 4a, 4b | May 15 - Jun 5 | Sep 5 - Sep 20 |
| Eastern Montana | 3a, 3b, 4a | May 10 - Jun 1 | Sep 10 - Sep 25 |
Kale Planting Schedule for Montana
Western Montana (Zones 4b, 5a, 5b)
Average last frost: May 10 - May 30 · Average first frost: Sep 10 - Sep 30
Central Montana (Zones 3b, 4a, 4b)
Average last frost: May 15 - Jun 5 · Average first frost: Sep 5 - Sep 20
Eastern Montana (Zones 3a, 3b, 4a)
Average last frost: May 10 - Jun 1 · Average first frost: Sep 10 - Sep 25
Growing Kale in Montana
Kale in Montana's Climate
Kale is your climate's superstar. It thrives in cool weather, survives hard frosts, and actually improves in flavor after cold exposure. In northern zones, kale produces from April through December — one of the longest harvests of any crop. Snow-covered kale harvested in December is genuinely sweeter than summer kale. If you grow nothing else in a cold climate, grow kale.
Soil Considerations for Montana
Alkaline soils common. Thin, dry soils in east. Better soils in valleys. Wind erosion challenges.
Montana Climate & Growing Season
Short, intense growing season. Low humidity. Wide day-night temperature swings. Wind protection valuable. Kale can handle frost well, which is an advantage in Montana's climate. You can push planting dates earlier in spring and extend into fall.
Growing season length varies across Montana: Western Montana (4b, 5a, 5b) has a last frost around May 10 - May 30, while Eastern Montana (3a, 3b, 4a) sees frost end around May 10 - Jun 1. This difference matters for kale — adjust your planting dates to match your specific region.
Growing Tips
Harvest outer leaves first, leaving the center to keep growing. Can survive temperatures down to 10°F with mulch protection.
Companion Planting
Plant kale alongside these companions for better growth:
Keep kale away from:
The Bottom Line
Last reviewed: March 29, 2026