§ When to plant · Idaho · Checked Sept 2026
In Boise City, tender crops like tomatoes and peppers can go out around May 12, and frost has historically passed 9 years in 10 by May 29. Cool-season crops go in from February.
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§ 010 · Frost dates
Based on NOAA's 1991–2020 station records, with adjustments for tender crops.
| City · NOAA station | Last frost, on average | Plant tender crops from | Frost is over, 9 of 10 years by | Fall frost possible from |
|---|---|---|---|---|
| AmmonIDAHO FALLS - KIFI · 6 km | May 9 | May 28May 28 | Jun 16 | Sep 17 |
| Boise CityBOISE AIR TERMINAL · 4 km | Apr 24 | May 12May 12 | May 29 | Oct 5 |
| CaldwellNAMPA SUGAR FACTORY · 8 km | Apr 29 | May 18May 18 | Jun 6 | Sep 29 |
| ChubbuckPOCATELLO 2 NORTHEAST · 6 km | May 16 | Jun 2June 2 | Jun 18 | Sep 14 |
| Coeur d'AleneCOEUR D'ALENE · 2 km | Apr 22 | May 7May 7 | May 21 | Oct 4 |
| EagleBOISE 7 N · 13 km | May 17 | Jun 5June 5 | Jun 23 | Sep 27 |
| HaydenCOEUR D'ALENE · 10 km | Apr 22 | May 7May 7 | May 21 | Oct 4 |
| Idaho FallsIDAHO FALLS - KIFI · 3 km | May 9 | May 28May 28 | Jun 16 | Sep 17 |
| JeromeJEROME · 2 km | May 2 | May 21May 21 | Jun 8 | Sep 30 |
| KunaBOISE AIR TERMINAL · 18 km | Apr 24 | May 12May 12 | May 29 | Oct 5 |
| LewistonLEWISTON NEZ PERCE COUNTY AIRPORT · 3 km | Apr 6 | Apr 24April 24 | May 12 | Oct 10 |
| MeridianBOISE AIR TERMINAL · 14 km | Apr 24 | May 12May 12 | May 29 | Oct 5 |
| MoscowPULLMAN MOSCOW REGIONAL AIRPORT · 8 km | Apr 29 | May 22May 22 | Jun 14 | Sep 17 |
| Mountain HomeMTN HOME · 1 km | May 2 | May 22May 22 | Jun 10 | Sep 25 |
| NampaNAMPA SUGAR FACTORY · 2 km | Apr 29 | May 18May 18 | Jun 6 | Sep 29 |
| PocatelloPOCATELLO CITY · 1 km | May 2 | May 19May 19 | Jun 5 | Sep 26 |
| Post FallsCOEUR D'ALENE · 11 km | Apr 22 | May 7May 7 | May 21 | Oct 4 |
| RexburgREXBURG BYU IDAHO · 2 km | May 12 | Jun 2June 2 | Jun 22 | Sep 6 |
| StarNAMPA SUGAR FACTORY · 13 km | Apr 29 | May 18May 18 | Jun 6 | Sep 29 |
| Twin FallsTWIN FALLS-KMVT · 2 km | Apr 30 | May 17May 17 | Jun 2 | Sep 24 |
Idaho's 20 largest cities (U.S. Census Bureau 2025 estimates), A to Z, each with its nearest NOAA station and the distance to it. Search any town to get its nearest station. "Plant tender crops from" is halfway between the average last frost and the date frost is over 9 years in 10; if frost is in the forecast after it, wait until it passes and nights stay above 36°F.
§ 020 · What to plant
Planting windows from Idaho's Cooperative Extension Service. Filter by season or crop group; every view has its own link.
Link to this view getezina.com/when-to-plant/idaho/
§ 030 · Crop by crop
Each crop has its own link, like #tomatoes. Tender crops wait for the frost dates above; succession crops are sown again every few weeks for a steady harvest.
Beta vulgaris
Cool seasonSuccession sow
Zones 3–4: sow May–Jun.
Zones 5–6: sow Apr–May.
Zone 7: sow Apr–May.
Ready in about 58 days; sow again every 6 weeks.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Brassica oleracea
Cool season
Zones 3–4: start seed indoors Apr–May; set out transplants May.
Zones 5–6: start seed indoors Mar–Apr; set out transplants Apr–May.
Zone 7: start seed indoors Mar–Apr; set out transplants Apr–May.
Ready in about 95 days from seed, 65 from transplants.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Brassica oleracea
Cool season
Zones 3–4: start seed indoors Apr–May; set out transplants May.
Zones 5–6: start seed indoors Mar–Apr; set out transplants Apr–May.
Zone 7: start seed indoors Mar–Apr; set out transplants Apr.
Ready in about 130 days from seed, 100 from transplants.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Brassica oleracea
Cool season
Zones 3–4: start seed indoors Apr; set out transplants May.
Zones 5–6: start seed indoors Mar–Apr; set out transplants Apr.
Zone 7: start seed indoors Mar; set out transplants Apr.
Ready in about 110 days from seed, 80 from transplants.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Cucumis melo
Tender
Zones 3–4: start seed indoors May; set out transplants Jun–Jul.
Zones 5–6: start seed indoors Apr; set out transplants May–Jun.
Zone 7: start seed indoors Apr; set out transplants May–Jun.
Ready in about 80 days from seed, 70 from transplants. Tender: in spring, from about May 12 in Boise City. If frost is in the forecast, hold off until it passes and nights stay above 36°F.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Daucus carota
Cool seasonSuccession sow
Zones 3–4: sow Apr–May.
Zones 5–6: sow Apr.
Zone 7: sow Mar–Apr.
Ready in about 70 days; sow again every 7 weeks.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Brassica oleracea
Cool season
Zones 3–4: start seed indoors Apr–May; set out transplants May.
Zones 5–6: start seed indoors Mar–Apr; set out transplants Apr.
Zone 7: start seed indoors Mar–Apr; set out transplants Apr.
Ready in about 95 days from seed, 68 from transplants.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Apium graveolens
Cool season
Zones 3–4: start seed indoors Mar–Apr; set out transplants Jun.
Zones 5–6: start seed indoors Mar; set out transplants May–Jun.
Zone 7: start seed indoors Feb–Mar; set out transplants May.
Ready in about 90 days from transplants.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Brassica oleracea
Cool season
Zones 3–4: start seed indoors Apr–May; set out transplants May.
Zones 5–6: start seed indoors Mar–Apr; set out transplants Apr–May.
Zone 7: start seed indoors Mar–Apr; set out transplants Apr.
Ready in about 65 days from seed, 55 from transplants.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Cucumis sativus
TenderSuccession sow
Zones 3–4: start seed indoors May; set out transplants Jun–Jul.
Zones 5–6: start seed indoors Apr; set out transplants May–Jun.
Zone 7: start seed indoors Apr; set out transplants May–Jun.
Ready in about 58 days from seed, 50 from transplants; sow again every 7 weeks. Tender: in spring, from about May 12 in Boise City. If frost is in the forecast, hold off until it passes and nights stay above 36°F.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Solanum melongena
Tender
Zones 3–4: start seed indoors Mar–Apr; set out transplants Jun–Jul.
Zones 5–6: start seed indoors Mar; set out transplants May–Jun.
Zone 7: start seed indoors Feb–Mar; set out transplants May.
Ready in about 75 days from transplants. Tender: in spring, from about May 12 in Boise City. If frost is in the forecast, hold off until it passes and nights stay above 36°F.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Brassica oleracea
Cool season
Zones 3–4: start seed indoors Apr–May; set out transplants May.
Zones 5–6: start seed indoors Mar–Apr; set out transplants Apr–May.
Zone 7: start seed indoors Mar–Apr; set out transplants Apr.
Ready in about 60 days from seed, 45 from transplants.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Brassica oleracea
Cool season
Zones 3–4: sow May.
Zones 5–6: sow Apr–May.
Zone 7: sow Apr.
Ready in about 55 days from seed, 45 from transplants.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Allium ampeloprasum
Cool season
Zones 3–4: start seed indoors Mar–Apr; set out transplants May.
Zones 5–6: start seed indoors Mar; set out transplants Apr–May.
Zone 7: start seed indoors Feb–Mar; set out transplants Apr.
Ready in about 130 days from seed, 100 from transplants.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Lactuca sativa
Cool seasonSuccession sow
Zones 3–4: start seed indoors Apr–May; set out transplants May–Jun.
Zones 5–6: start seed indoors Mar–Apr; set out transplants Apr–May.
Zone 7: start seed indoors Mar–Apr; set out transplants Apr–May.
Ready in about 65 days from seed, 50 from transplants; sow again every 6 weeks.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Abelmoschus esculentus
Tender
Zones 3–4: sow Jun.
Zones 5–6: sow May–Jun.
Zone 7: sow May.
Ready in about 55 days from seed, 45 from transplants. Tender: in spring, from about May 12 in Boise City. If frost is in the forecast, hold off until it passes and nights stay above 36°F.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Allium cepa
Cool season
Zones 3–4: sow May.
Zones 5–6: sow Apr–May.
Zone 7: sow Apr.
Ready in about 110 days from seed, 95 from transplants.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Pastinaca sativa
Cool season
Zones 3–4: sow May.
Zones 5–6: sow Apr–May.
Zone 7: sow Apr–May.
Ready in about 120 days.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Pisum sativum
Cool seasonSuccession sow
Zones 3–4: sow Apr–May.
Zones 5–6: sow Mar–Apr.
Zone 7: sow Mar–Apr.
Ready in about 65 days; sow again every 5 weeks.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Capsicum annuum
Tender
Zones 3–4: start seed indoors Mar–Apr; set out transplants Jun–Jul.
Zones 5–6: start seed indoors Mar; set out transplants May–Jun.
Zone 7: start seed indoors Feb–Mar; set out transplants May–Jun.
Ready in about 70 days from transplants. Tender: in spring, from about May 12 in Boise City. If frost is in the forecast, hold off until it passes and nights stay above 36°F.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Solanum tuberosum
Cool season
Zones 3–4: sow May–Jun.
Zones 5–6: sow May.
Zone 7: sow Apr–May.
Ready in about 100 days.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Cucurbita pepo
Tender
Zones 3–4: start seed indoors May; set out transplants Jun–Jul.
Zones 5–6: start seed indoors Apr; set out transplants May–Jun.
Zone 7: start seed indoors Apr; set out transplants May–Jun.
Ready in about 110 days from seed, 95 from transplants. Tender: in spring, from about May 12 in Boise City. If frost is in the forecast, hold off until it passes and nights stay above 36°F.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Raphanus sativus
Cool seasonSuccession sow
Zones 3–4: sow Apr.
Zones 5–6: sow Mar–Apr.
Zone 7: sow Mar.
Ready in about 28 days; sow again every 3 weeks.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Spinacia oleracea
Cool seasonSuccession sow
Zones 3–4: sow Apr–May.
Zones 5–6: sow Mar–Apr.
Zone 7: sow Mar–Apr.
Ready in about 42 days; sow again every 5 weeks.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Cucurbita pepo
TenderSuccession sow
Zones 3–4: start seed indoors May; set out transplants Jun–Jul.
Zones 5–6: start seed indoors Apr; set out transplants May–Jun.
Zone 7: start seed indoors Apr; set out transplants May–Jun.
Ready in about 50 days from seed, 40 from transplants; sow again every 7 weeks. Tender: in spring, from about May 12 in Boise City. If frost is in the forecast, hold off until it passes and nights stay above 36°F.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Zea mays
TenderSuccession sow
Zones 3–4: sow May–Jun.
Zones 5–6: sow May.
Zone 7: sow May.
Ready in about 78 days; sow again every 6 weeks. Tender: in spring, from about May 12 in Boise City. If frost is in the forecast, hold off until it passes and nights stay above 36°F.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Ipomoea batatas
Tender
Zones 3–4: start seed indoors May; set out transplants Jun–Jul.
Zones 5–6: start seed indoors Apr; set out transplants May–Jun.
Zone 7: start seed indoors Apr; set out transplants May–Jun.
Ready in about 100 days from transplants. Tender: in spring, from about May 12 in Boise City. If frost is in the forecast, hold off until it passes and nights stay above 36°F.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Beta vulgaris
Cool season
Zones 3–4: start seed indoors Apr–May; set out transplants May.
Zones 5–6: start seed indoors Mar–Apr; set out transplants Apr.
Zone 7: start seed indoors Mar–Apr; set out transplants Apr.
Ready in about 55 days from seed, 40 from transplants.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Solanum lycopersicum
Tender
Zones 3–4: start seed indoors Apr; set out transplants Jun.
Zones 5–6: start seed indoors Mar; set out transplants May–Jun.
Zone 7: start seed indoors Mar; set out transplants May.
Ready in about 75 days from transplants. Tender: in spring, from about May 12 in Boise City. If frost is in the forecast, hold off until it passes and nights stay above 36°F.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Brassica rapa
Cool seasonSuccession sow
Zones 3–4: sow May.
Zones 5–6: sow Apr–May.
Zone 7: sow Apr.
Ready in about 50 days; sow again every 5 weeks.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
Citrullus lanatus
Tender
Zones 3–4: start seed indoors May; set out transplants Jun–Jul.
Zones 5–6: start seed indoors Apr; set out transplants May–Jun.
Zone 7: start seed indoors Apr; set out transplants May–Jun.
Ready in about 85 days from seed, 75 from transplants. Tender: in spring, from about May 12 in Boise City. If frost is in the forecast, hold off until it passes and nights stay above 36°F.
Source: University of Idaho Extension, Spring Vegetable Planting Guide for Idaho. Days to harvest: Ezina crop catalog, from state extension guides.
§ 040 · Questions
On average from about April 6 in Lewiston to May 17 in Eagle. Frost is over 9 years in 10 by May 12 to June 23.
The extension service lists March to June. Tomatoes are frost-tender, so Ezina dates them from about May 12 in Boise City. If frost is in the forecast, wait until it passes.
A zone is the coldest winter night, not a frost date. These dates come from NOAA station records and the extension service.
Yes. Run Ezina Dig on your address and your bed plans are dated from that site's own frost records, on iPhone and Android in the contiguous U.S.