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When to Plant Leeks in Utah

Leeks are a mild, sweet allium that produces long white shanks. They are more refined than onions and are a key ingredient in soups, stews, and gratins.

Utah spans USDA hardiness zones 4b, 5a, 5b, 6a, 6b, 8a (with planting data available), so planting dates vary by your location within the state. Click your zone below for the most accurate dates.

Find Your County

Click your county for exact Leeks planting dates based on your local frost dates.

Hover over a county to see details. Click to view planting guide.

Leeks Planting Calendar for Utah

Zone 4b ~155 day growing season · Full guide →

Last frost: May 1 · First frost: October 3 · 155 day season

Activity When Date Range
Start Indoors March 20 Mar 20 – Apr 3
Transplant Outdoors May 1 May 1 – May 15
Direct Sow April 24 Apr 24 – May 15
Fall Sowing July 11 Jul 11 – Jul 25
Harvest July 31 Jul 31 – Sep 25
Zone 5a ~166 day growing season · Full guide →

Last frost: April 25 · First frost: October 8 · 166 day season

Activity When Date Range
Start Indoors March 21 Mar 21 – Apr 4
Transplant Outdoors April 25 Apr 25 – May 9
Direct Sow April 11 Apr 11 – May 2
Fall Sowing July 30 Jul 30 – Aug 13
Harvest July 25 Jul 25 – Oct 10
Zone 5b ~178 day growing season · Full guide →

Last frost: April 18 · First frost: October 13 · 178 day season

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors April 18 Apr 18 – May 2
Direct Sow April 4 Apr 4 – Apr 25
Fall Sowing August 4 Aug 4 – Aug 18
Harvest July 18 Jul 18 – Oct 3
Zone 6a ~193 day growing season · Full guide →

Last frost: April 10 · First frost: October 20 · 193 day season

Activity When Date Range
Start Indoors March 6 Mar 6 – Mar 20
Transplant Outdoors April 10 Apr 10 – Apr 24
Direct Sow March 27 Mar 27 – Apr 17
Fall Sowing August 11 Aug 11 – Aug 25
Harvest July 10 Jul 10 – Sep 25
Zone 6b ~205 day growing season · Full guide →

Last frost: April 3 · First frost: October 25 · 205 day season

Activity When Date Range
Start Indoors February 27 Feb 27 – Mar 13
Transplant Outdoors April 3 Apr 3 – Apr 17
Direct Sow March 20 Mar 20 – Apr 10
Fall Sowing August 16 Aug 16 – Aug 30
Harvest July 3 Jul 3 – Sep 18
Zone 8a ~255 day growing season · Full guide →

Last frost: March 8 · First frost: November 18 · 255 day season

Activity When Date Range
Start Indoors February 1 Feb 1 – Feb 15
Transplant Outdoors March 8 Mar 8 – Mar 22
Direct Sow February 22 Feb 22 – Mar 15
Fall Sowing September 9 Sep 9 – Sep 23
Harvest June 7 Jun 7 – Aug 23

Growing Tips for Utah

Start seeds indoors 10-12 weeks before last frost. Transplant into trenches and hill soil around stems as they grow to increase the white portion. Harvest as needed.

Frequently Asked Questions

When should I plant Leeks in Utah?

Planting dates for Leeks in Utah depend on your USDA zone. Utah spans zones 4b, 5a, 5b, 6a, 6b, 8a. Check the planting calendar above for your specific zone's frost dates and planting windows.

What zone is Utah for planting?

Utah contains USDA hardiness zones 4b, 5a, 5b, 6a, 6b, 8a. Your specific zone depends on your location within the state — northern and higher-elevation areas are in colder zones, while southern and coastal areas are warmer.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals, University Cooperative Extension planting guides. Last updated: April 2026.