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Montana Planting Guide & Growing Season

Montana is in USDA hardiness zone with a growing season of 120 days. The average last spring frost is May 1 - Jun 15 and the average first fall frost is Sep 1 - Oct 1.

USDA Zone Hardiness zone
Last Frost May 1 - Jun 15 Average spring
First Frost Sep 1 - Oct 1 Average fall
Growing Season 120 days Short season

Growing Conditions in Montana

USDA Hardiness Zone
Average Last FrostMay 1 - Jun 15
Average First FrostSep 1 - Oct 1
Growing Season Length120 days

How Montana Compares

Compare Montana's growing conditions with states that have similar climates.

StateUSDA ZoneLast FrostFirst FrostSeason (days)
Montana (MT) May 1 - Jun 15Sep 1 - Oct 1120
Alabama (AL) Mar 1 - Apr 1Oct 25 - Nov 15220
Alaska (AK) May 15 - Jun 15Aug 15 - Sep 15105
Arizona (AZ) Feb 1 - Apr 15Oct 15 - Dec 15270
Arkansas (AR) Mar 15 - Apr 15Oct 15 - Nov 1210
California (CA) Jan 15 - Apr 15Oct 15 - Dec 31290

Frequently Asked Questions About Gardening in Montana

When should I start seeds indoors in Montana?

In Montana, the average last frost date is May 1 - Jun 15. Start most seeds indoors 6-8 weeks before this date. The USDA hardiness zone for Montana is undefined, with a growing season of approximately 120 days.

What USDA hardiness zone is Montana?

Montana falls in USDA hardiness zones undefined. This affects which perennial plants will survive winter and influences optimal planting times.

When is the first frost in Montana?

The average first frost date in Montana is Sep 1 - Oct 1. Plan to harvest cold-sensitive crops before this date or protect them with row covers.

How long is the growing season in Montana?

Montana has an average growing season of 120 days, from the last frost (May 1 - Jun 15) to first frost (Sep 1 - Oct 1). This shorter season requires starting many crops indoors and choosing quick-maturing varieties.

Plan Your Garden

Use our seed starting calculator to get personalized planting dates, or browse all states.

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