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Montana Planting Calendar

Montana spans USDA hardiness zones 3a, 3b, 4a, 4b, 5a, 5b. Planting dates vary significantly across the state depending on your zone. Find your county on the map below for exact frost dates and planting windows.

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Find Your County

Click any county to see your local planting calendar with exact frost dates and planting windows.

Zones in Montana

Growing Season Comparison

Frost Dates & Growing Season by County

View all 56 Montana counties with frost dates
County Zone Last Frost First Frost Growing Days
Beaverhead County 5a Jun 10 Sep 12 94
Big Horn County 5a May 13 Sep 30 140
Blaine County 4a May 14 Sep 24 133
Broadwater County 5a May 20 Sep 20 123
Carbon County 5a May 13 Sep 28 138
Carter County 4b May 15 Sep 22 130
Cascade County 4b May 19 Sep 21 125
Chouteau County 4a May 12 Sep 27 138
Custer County 4b May 14 Sep 27 136
Daniels County 3b May 20 Sep 16 119
Dawson County 4a May 14 Sep 22 131
Deer Lodge County 5a Jun 15 Sep 7 84
Fallon County 4b May 20 Sep 20 123
Fergus County 4b May 20 Sep 20 123
Flathead County 5a Jun 3 Sep 10 99
Gallatin County 5a Jun 8 Sep 19 103
Garfield County 4b May 16 Sep 21 128
Glacier County 4b May 22 Sep 18 119
Golden Valley County 4b May 22 Sep 20 121
Granite County 5a May 29 Sep 20 114
Hill County 4a May 14 Sep 23 132
Jefferson County 5a Jun 15 Sep 7 84
Judith Basin County 4b May 23 Sep 19 119
Lake County 6a May 31 Sep 12 104
Lewis and Clark County 4b May 29 Sep 18 112
Liberty County 4a May 26 Sep 15 112
Lincoln County 5a May 16 Sep 23 130
Madison County 5a Jun 11 Sep 13 94
McCone County 4a May 14 Sep 22 131
Meagher County 4b Jun 10 Sep 8 90
Mineral County 6a May 30 Sep 20 113
Missoula County 5b May 14 Sep 23 132
Musselshell County 4b May 14 Sep 23 132
Park County 5a May 24 Sep 20 119
Petroleum County 4b May 18 Sep 24 129
Phillips County 3b May 18 Sep 21 126
Pondera County 4a May 23 Sep 16 116
Powder River County 4b May 15 Sep 22 130
Powell County 4b Jun 6 Sep 8 94
Prairie County 4a May 11 Oct 1 143
Ravalli County 5b May 21 Sep 20 122
Richland County 4a May 14 Sep 20 129
Roosevelt County 4a May 17 Sep 18 124
Rosebud County 4b May 11 Oct 3 145
Sanders County 6a May 24 Sep 13 112
Sheridan County 3b May 17 Sep 18 124
Silver Bow County 5a Jun 15 Sep 7 84
Stillwater County 5a May 22 Sep 22 123
Sweet Grass County 5a May 22 Sep 19 120
Teton County 4b May 25 Sep 16 114
Toole County 4a May 24 Sep 17 116
Treasure County 4b May 11 Oct 1 143
Valley County 4a May 13 Sep 21 131
Wheatland County 4b May 19 Sep 21 125
Wibaux County 4a May 14 Sep 22 131
Yellowstone County 5a May 9 Oct 3 147
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🥬 Vegetables

Browse all 116 vegetables you can grow in Montana

🍓 Fruits

Browse all 34 fruits you can grow in Montana

🌿 Herbs

Browse all 42 herbs you can grow in Montana

Monthly Planting Guide for Montana

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.