Planting Dates for Idaho
Idaho is famous for its potatoes, but the state's volcanic soils and sunny climate support diverse vegetable production. The Snake River Valley offers the best growing conditions, while northern Idaho is cooler and wetter.
USDA Zones 3b-7a • 90-165 frost-free days depending on location
Frost Dates in Idaho
Average last spring frost and first fall frost dates for Idaho cities. Use these to calculate your planting windows.
| City | Last Spring Frost | First Fall Frost | Frost-Free Days | USDA Zone |
|---|---|---|---|---|
| Boise | May 6 | Oct 5 | 152 | 7a |
| Idaho Falls | May 21 | Sep 17 | 119 | 5b |
| Twin Falls | May 12 | Sep 27 | 138 | 6b |
Gardening Tips for Idaho
- ✓The Treasure Valley (Boise area) has Idaho's longest growing season.
- ✓Northern Idaho gets more rainfall — similar growing to the Pacific Northwest.
- ✓Idaho's volcanic soils are naturally rich in minerals for vegetable production.
- ✓Plan for last frost in mid-May in the south, late May to early June in the north.
What to Plant in Idaho
Cold-Hardy Crops (plant early)
These crops tolerate frost and can be planted 2-6 weeks before your last frost date.
30-60 days from sowing
55-70 days from sowing
60-80 days from sowing
50-70 days from sowing
55-80 days from transplant
35-50 days from sowing
20-35 days from sowing
July-August the following year
90-120 days from transplant
70-120 days from planting
50-70 days from sowing
50-60 days from sowing
Warm-Season Crops (plant after last frost)
Start these indoors and transplant after all frost danger has passed.
60-85 days from transplant
60-90 days from transplant
50-65 days from sowing
50-65 days from sowing
45-60 days from sowing
60-100 days from sowing
30-60 days from sowing
Get Exact Planting Dates for Idaho
Enter your city's frost date and get precise seed starting, transplant, and harvest dates for 38+ vegetables — free.
Frequently Asked Questions
When is the last frost date in Idaho?
Last frost dates in Idaho vary by city: Boise (May 6), Idaho Falls (May 21), Twin Falls (May 12).
What USDA hardiness zones are in Idaho?
Idaho spans USDA hardiness zones 3b-7a. Your specific zone determines which perennials survive winter and when to start planting annuals.
What vegetables grow best in Idaho?
Hardy crops like peas, kale, spinach, and garlic thrive across Idaho. In warmer zones, tomatoes, peppers, and cucumbers do well with proper timing. Use our free calculator for exact planting dates.
How long is the growing season in Idaho?
90-165 frost-free days depending on location. Extend your season with cold frames, row covers, and indoor seed starting.
Planting Dates by State
Explore More Resources
Planting Dates by Province
Province-specific planting dates, zones, and growing tips for all 10 provinces.
US State Planting Dates
USDA zones, frost dates, and growing tips for all 50 US states.
Frost Dates Canada
Find your last spring frost and first fall frost dates by province.
When to Plant Vegetables
19 popular crops with timing, frost tolerance, and Canadian tips.
Succession Planting
Plan continuous harvests with succession planting schedules.
Free Calculator
Calculate exact planting dates based on your location and frost dates.