When to plant in Montana
Montana spans USDA hardiness zones 3-6. Average last spring frost: late May. Average first fall frost: mid September. This calendar is anchored to Montana State Extension's recommendations, with timing adjusted for the dominant climate zone of the state.
Montana at a glance
| USDA hardiness zones | 3-6 |
| Region | Mountain West |
| Average last spring frost | late May |
| Average first fall frost | mid September |
| Primary Extension service | Montana State Extension |
What grows particularly well in Montana
These are the crops, ornamentals, and trees Montana State Extension highlights as well-suited to Montana's climate:
- wheat
- potato
- sugar beet
- peony
- aspen
- wildflower mixes
Montana planting calendar
Dates are approximate and based on the dominant USDA zone for the state. For zone-specific timing, use the zone finder by ZIP code and frost date lookup tools.
Spring planting (after last frost: late May)
Cool-season vegetables (start 2-6 weeks before last frost outdoors): lettuce, spinach, peas, radishes, carrots, beets, kale, broccoli transplants, cabbage transplants.
Warm-season vegetables (after last frost, soil 60F+): tomato transplants, pepper transplants, beans (direct sow), cucumbers, squash, melons. See the seed starting timeline tool for indoor start dates.
Annual flowers (after last frost): zinnia, marigold, cosmos, sunflower, nasturtium.
Perennials, shrubs, trees: Plant in spring after soil thaws but before summer heat. Best window in Montana: 4-6 weeks after last frost.
Summer (June - August)
Maintenance season for most Montana gardens. Mulch heavily, water deeply (1 inch per week), pinch back mums for fall bloom, hand-pull weeds, harvest summer vegetables. Plant fall vegetable starts indoors by mid-July.
Fall planting (before first frost: mid September)
Cool-season vegetables (6-8 weeks before first frost): lettuce, spinach, radish, kale, broccoli, cabbage transplants. Per Penn State Extension, fall vegetable production can equal or exceed spring production with proper timing.
Spring-flowering bulbs: tulip, daffodil, allium, crocus, hyacinth. Plant 4-6 weeks before ground freezes. In Montana: typically October-November.
Perennials, shrubs, trees: Fall is the best planting season for woody plants in most of Montana - cooler temperatures + autumn rains reduce transplant stress. Plant 6+ weeks before first hard freeze.
Garlic: Plant cloves in October-November. Harvest the following July.
Winter (December - February)
Most of Montana is in dormancy. Tasks: order seeds, plan next year, dormant prune fruit trees (February), order bare-root plants for spring delivery. Avoid foot traffic on frozen lawns.
Common Montana challenges
Short growing season; extreme cold; chinook winds; alkaline soils; deer and elk pressure; wildfire smoke summers. For region-specific guidance, see our Mountain West regional gardening guide.
Where to get Montana-specific advice
The most reliable source for local growing advice is your county Extension office. Montana State Extension has county offices that provide free soil testing, plant disease diagnosis, and growing recommendations specific to your microclimate.
Visit Montana State Extension for the office nearest you.
Related tools and guides
- Find your USDA zone by ZIP code
- Look up your average frost dates
- Seasonal care calendar by zone
- Seed starting timeline calculator
- Mountain West regional gardening guide