Cool-Season Vegetable

When to Plant Broccoli in Montana

A nutrition powerhouse that thrives in cool weather. Harvest the main head, then enjoy weeks of side shoots.

The Short Answer

Broccoli 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

Broccoli 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
6 wks before frost
Transplant Outside
2 wks before frost
Direct Sow
4 wks before frost
Fall Planting
10 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
6 wks before frost
Transplant Outside
2 wks before frost
Direct Sow
4 wks before frost
Fall Planting
10 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
6 wks before frost
Transplant Outside
2 wks before frost
Direct Sow
4 wks before frost
Fall Planting
10 wks before first frost

Growing Broccoli in Montana

Broccoli in Montana's Climate

Broccoli thrives in your cool climate. Spring planting works well — transplant 2-3 weeks before last frost. Unlike warmer regions where heat causes premature bolting, your moderate summer temperatures often allow extended broccoli harvests. Fall broccoli is equally productive. Northern Michigan, Minnesota, and Wisconsin can even grow broccoli through summer in cooler years.

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. Broccoli 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 broccoli — but broccoli handle frost well, so the timing difference is less critical.

Growing Tips

Harvest main head while buds are tight. Side shoots will continue producing for weeks after the main harvest.

Companion Planting

Plant broccoli alongside these companions for better growth:

Beets Celery Onions Potatoes

Keep broccoli away from:

Tomatoes Peppers Strawberries

The Bottom Line

Broccoli 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.

Related Guides

Broccoli Growing Guide National planting guide with all states Montana Planting Calendar All plants for Montana Broccoli in Alabama Alabama planting dates Broccoli in Alaska Alaska planting dates Broccoli in Arizona Arizona planting dates Broccoli in Arkansas Arkansas planting dates
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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