Herb

When to Plant Parsley in Idaho

More than a garnish. Parsley is a biennial that produces abundantly its first year and is one of the most nutritious herbs.

The Short Answer

Parsley are planted in fall in Idaho, 8 weeks before your first frost date. That means planting around Sep 15 - Oct 5 in Northern Idaho.

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

Parsley 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 before frost
Direct Sow
3 wks before frost
Fall Planting
8 wks before first 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 before frost
Direct Sow
3 wks before frost
Fall Planting
8 wks before first 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 before frost
Direct Sow
3 wks before frost
Fall Planting
8 wks before first frost

Growing Parsley in Idaho

Parsley in Idaho's Climate

Parsley is one of your most reliable herbs — the biennial handles frost, grows through your moderate summers, and keeps producing from May through November. Start seeds indoors in February (parsley germinates notoriously slowly — 14-28 days). The plant is biennial: lush leaves year one, flowers and seeds year two.

Soil Considerations for Idaho

Volcanic ash soils in south — excellent for gardening. Rocky soils in mountains. Alkaline in many areas.

Idaho Climate & Growing Season

Arid climate. Low humidity. Hot days and cool nights. Irrigation essential. Short season at higher elevations.

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 parsley — adjust your planting dates to match your specific region.

Growing Tips

Parsley seeds are notoriously slow to germinate — soak overnight before planting. It's a biennial: lush leaves year one, seeds year two.

Companion Planting

Plant parsley alongside these companions for better growth:

Tomatoes Asparagus Corn

The Bottom Line

Parsley 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.
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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