When to Plant Squash in Idaho
Direct Sow Outdoors
Wednesday, March 4, 2026
State
Idaho
USDA Zones
4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b
Avg Last Frost
Wednesday, April 15, 2026
Cities Covered
264
Idaho Planting Schedule by Zone
Idaho spans 8 zones — find yours below for the most accurate dates.
| Zone | Last Frost | Direct Sow |
|---|---|---|
| 4a | Friday, May 15, 2026 | Friday, April 3, 2026 |
| 4b | Tuesday, May 5, 2026 | Tuesday, March 24, 2026 |
| 5a | Sunday, May 10, 2026 | Sunday, March 29, 2026 |
| 5b | Saturday, April 25, 2026 | Saturday, March 14, 2026 |
| 6a | Monday, April 20, 2026 | Monday, March 9, 2026 |
| 6b | Wednesday, April 15, 2026 | Wednesday, March 4, 2026 |
| 7a | Friday, April 10, 2026 | Friday, February 27, 2026 |
| 7b | Sunday, April 5, 2026 | Sunday, February 22, 2026 |
Dates based on average last frost. Check your local forecast before planting.
🌿 About Squash
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Growing Squash in Idaho: Complete Guide
Squash (Cucurbita moschata) is a crop that grows best when sown directly in the garden. In Idaho, the right time to direct sow is around Wednesday, March 4, 2026, once soil temperatures are consistently warm enough for germination.
Because Idaho stretches across 8 USDA hardiness zones (4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b), planting windows can shift by as much as six to eight weeks from one end of the state to the other. Gardeners in the warmer southern zones can start earlier, while those in cooler northern zones should wait until the zone table above shows their last frost has passed.
With 90 days to maturity, Squash fits comfortably within Idaho's growing season in most zones. In the warmest parts of the state, a second planting later in the season may be possible.
Squash requires full sun (6-8 hours) and regular (1 inch/week) moisture. Most of Idaho receives adequate sunlight during the growing season, though gardeners in humid eastern regions should watch for fungal issues and ensure good air circulation.
For the most precise planting dates tailored to your exact location, enter your ZIP code on our planting calendar or use the zone table above to find the schedule for your area of Idaho.
Frequently Asked Questions
When should I plant Squash in Idaho?
In Idaho, direct sow Squash outdoors around Wednesday, March 4, 2026. Idaho spans zones 4a–7b, so gardeners in warmer zones can plant earlier.
What is the last frost date in Idaho?
Idaho spans 8 USDA zones (4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b), so last frost dates vary by region. Island Park, Macks Inn (4a) sees frost until around Friday, May 15, 2026, while Lewiston, Juliaetta, Lapwai (7b) is frost-free much earlier.
How long does Squash take to grow in Idaho?
Squash takes about 90 days from transplant (or direct sow) to harvest. In Idaho's longer-season zones, a second planting in late summer may be possible.
What USDA zones does Idaho cover for Squash?
Idaho includes zones 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b. Squash grows well across all of these zones with adjusted timing — use the zone table above to find the right dates for your part of the state.
Find Precise Dates for Your City
Select a city for exact planting dates based on local frost records.