Warm-Season Vegetable

When to Plant Peppers in Idaho

From sweet bells to fiery habaneros, peppers love heat and reward patience with prolific harvests.

The Short Answer

In Idaho, peppers planting dates vary by region. In Northern Idaho, your average last frost is around May 5 - May 25, while Eastern Idaho sees its last frost around May 20 - Jun 10. Since peppers are frost-sensitive, start seeds indoors 8 weeks before your last frost, then transplant outside 2 weeks after frost danger has passed. Volcanic ash soils in south — excellent for gardening. Rocky soils in mountains. Alkaline in many areas.

Idaho Frost Dates

Your planting dates depend on which part of Idaho you're in. Here are the frost date ranges by region:

Region Zones Last Frost (Spring) First Frost (Fall)
Northern Idaho 5a, 5b, 6a May 5 - May 25 Sep 15 - Oct 5
Boise Area 6b, 7a Apr 20 - May 5 Oct 5 - Oct 20
Eastern Idaho 3b, 4a, 4b, 5a May 20 - Jun 10 Sep 1 - Sep 20

Peppers Planting Schedule for Idaho

Northern Idaho (Zones 5a, 5b, 6a)

Average last frost: May 5 - May 25 · Average first frost: Sep 15 - Oct 5

Start Seeds Indoors
8 wks before frost
Transplant Outside
2 wks after frost

Boise Area (Zones 6b, 7a)

Average last frost: Apr 20 - May 5 · Average first frost: Oct 5 - Oct 20

Start Seeds Indoors
8 wks before frost
Transplant Outside
2 wks after frost

Eastern Idaho (Zones 3b, 4a, 4b, 5a)

Average last frost: May 20 - Jun 10 · Average first frost: Sep 1 - Sep 20

Start Seeds Indoors
8 wks before frost
Transplant Outside
2 wks after frost

Growing Peppers in Idaho

Peppers in Idaho's Climate

Peppers need even more heat than tomatoes, making them one of the most challenging warm-season crops in cold climates. Start seeds indoors 8-10 weeks before your last frost and don't transplant until nighttime temperatures are consistently above 60°F. Choose fast-maturing varieties like Early Jalapeño (60 days) and King of the North (68 days). Wall-o-Water season extenders and black plastic mulch are game-changers for cold-climate pepper growers.

Soil Considerations for Idaho

Volcanic ash soils in south — excellent for gardening. Rocky soils in mountains. Alkaline in many areas. Make sure soil has warmed to at least 65°F before planting peppers outside.

Idaho Climate & Growing Season

Arid climate. Low humidity. Hot days and cool nights. Irrigation essential. Short season at higher elevations. Peppers cannot tolerate any frost, so wait until all frost danger has passed before transplanting outside. Watch local forecasts carefully in spring.

Growing season length varies across Idaho: Northern Idaho (5a, 5b, 6a) has a last frost around May 5 - May 25, while Eastern Idaho (3b, 4a, 4b, 5a) sees frost end around May 20 - Jun 10. This difference matters for peppers — transplant timing shifts by several weeks across the state.

Growing Tips

Start seeds early — peppers are slow to germinate. Wait until nights are consistently above 55°F before transplanting.

Companion Planting

Plant peppers alongside these companions for better growth:

Tomatoes Basil Carrots Onions

Keep peppers away from:

Fennel Kohlrabi

The Bottom Line

Peppers can be grown successfully across Idaho, but your exact planting dates depend on which region you're in. Northern Idaho gardeners should plan around a May 5 - May 25 last frost, while those in Eastern Idaho can typically plant later. For exact dates based on your zip code, use our free planting date finder.

Related Guides

Peppers Growing Guide National planting guide with all states Idaho Planting Calendar All plants for Idaho Peppers in Alabama Alabama planting dates Peppers in Alaska Alaska planting dates Peppers in Arizona Arizona planting dates Peppers in Arkansas Arkansas planting dates
Note: All dates are based on NOAA 30-year Climate Normals and represent historical averages, not predictions for any specific year. Always check your local weather forecast before planting frost-sensitive crops. Learn about our data sources.

Last reviewed: March 29, 2026

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