Cool-Season Vegetable

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

Kale are cold-tolerant and do well in Montana's humid climate. You can direct sow 4 weeks before your last frost — that's as early as May 10 - May 30 in Western Montana. Montana gardeners can also plant a fall crop. Alkaline soils common. Thin, dry soils in east. Better soils in valleys. Wind erosion challenges.

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

Start Seeds Indoors
4 wks before frost
Transplant Outside
3 wks before frost
Direct Sow
4 wks before frost
Fall Planting
8 wks before first frost

Central Montana (Zones 3b, 4a, 4b)

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

Start Seeds Indoors
4 wks before frost
Transplant Outside
3 wks before frost
Direct Sow
4 wks before frost
Fall Planting
8 wks before first frost

Eastern Montana (Zones 3a, 3b, 4a)

Average last frost: May 10 - Jun 1 · Average first frost: Sep 10 - Sep 25

Start Seeds Indoors
4 wks before frost
Transplant Outside
3 wks before frost
Direct Sow
4 wks before frost
Fall Planting
8 wks before first frost

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:

Beets Celery Herbs Onions

Keep kale away from:

Strawberries Tomatoes

The Bottom Line

Kale can be grown successfully across Montana, but your exact planting dates depend on which region you're in. Western Montana gardeners should plan around a May 10 - May 30 last frost, while those in Eastern Montana 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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