Montana Planting Guide & Growing Season
Montana is in USDA hardiness zone 3a-6a with a growing season of 120 days. The average last spring frost is May 20 and the average first fall frost is Sep 15.
Growing Conditions in Montana
How Montana Compares
Compare Montana's growing conditions with states that have similar climates.
| State | USDA Zone | Last Frost | First Frost | Season (days) |
|---|---|---|---|---|
| Montana (MT) | 3a-6a | May 20 | Sep 15 | 120 |
| Alabama (AL) | 7a-8b | Mar 15 | Nov 5 | 235 |
| Alaska (AK) | 1a-7b | May 30 | Sep 5 | 100 |
| Arizona (AZ) | 4b-10b | Mar 1 | Nov 15 | 260 |
| Arkansas (AR) | 6b-8a | Apr 1 | Oct 25 | 210 |
| California (CA) | 4b-11a | Feb 15 | Nov 30 | 290 |
Frequently Asked Questions About Gardening in Montana
When should I start seeds indoors in Montana?
In Montana, the average last frost date is May 20. Start most seeds indoors 6-8 weeks before this date. The USDA hardiness zone for Montana is 3a-6a, with a growing season of approximately 120 days.
What USDA hardiness zone is Montana?
Montana falls in USDA hardiness zones 3a-6a. 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 15. 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 20) to first frost (Sep 15). 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.