Warm-Season Vegetable

When to Plant Tomatoes in Utah

America's favorite garden vegetable (technically a fruit). Nothing beats a sun-warmed tomato straight off the vine.

The Short Answer

In Utah, tomatoes planting dates vary by region. In Wasatch Front (SLC), your average last frost is around Apr 20 - May 10, while Southern Utah sees its last frost around Apr 10 - May 1. Since tomatoes are frost-sensitive, start seeds indoors 6 weeks before your last frost, then transplant outside 2 weeks after frost danger has passed. Alkaline desert soils. Low organic matter. Saline soils in some areas. Heavy amendment with compost and sulfur needed.

Utah Frost Dates

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

Region Zones Last Frost (Spring) First Frost (Fall)
Wasatch Front (SLC) 6a, 6b, 7a Apr 20 - May 10 Oct 1 - Oct 20
Mountain Regions 4a, 4b, 5a May 25 - Jun 15 Aug 25 - Sep 15
Southern Utah 6b, 7a, 7b Apr 10 - May 1 Oct 10 - Nov 1

Tomatoes Planting Schedule for Utah

Wasatch Front (SLC) (Zones 6a, 6b, 7a)

Average last frost: Apr 20 - May 10 · Average first frost: Oct 1 - Oct 20

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks after frost
Direct Sow
2 wks after frost

Mountain Regions (Zones 4a, 4b, 5a)

Average last frost: May 25 - Jun 15 · Average first frost: Aug 25 - Sep 15

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks after frost
Direct Sow
2 wks after frost

Southern Utah (Zones 6b, 7a, 7b)

Average last frost: Apr 10 - May 1 · Average first frost: Oct 10 - Nov 1

Start Seeds Indoors
6 wks before frost
Transplant Outside
2 wks after frost
Direct Sow
2 wks after frost

Growing Tomatoes in Utah

Tomatoes in Utah's Climate

Your long growing season gives tomatoes plenty of time, but extreme summer heat above 95°F can cause blossom drop and pause fruit set during the hottest weeks. In the Deep South and Texas, many growers aim for two tomato seasons — spring (transplant early) and fall (start new plants in July). Choose heat-tolerant varieties like Heat Wave, Solar Fire, and Phoenix. Afternoon shade from taller plants can help during the most brutal July-August heat.

Soil Considerations for Utah

Alkaline desert soils. Low organic matter. Saline soils in some areas. Heavy amendment with compost and sulfur needed. Make sure soil has warmed to at least 60°F before planting tomatoes outside.

Utah Climate & Growing Season

Arid climate. Intense sun. Low humidity. Wide temperature swings. Irrigation essential everywhere. Tomatoes 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 Utah: Wasatch Front (SLC) (6a, 6b, 7a) has a last frost around Apr 20 - May 10, while Southern Utah (6b, 7a, 7b) sees frost end around Apr 10 - May 1. This difference matters for tomatoes — transplant timing shifts by several weeks across the state.

Growing Tips

Pinch off suckers for indeterminate varieties. Stake or cage for best results. Water at the base, not overhead, to prevent blight.

Companion Planting

Plant tomatoes alongside these companions for better growth:

Basil Carrots Peppers Marigolds

Keep tomatoes away from:

Brassicas Fennel Dill

The Bottom Line

Tomatoes can be grown successfully across Utah, but your exact planting dates depend on which region you're in. Wasatch Front (SLC) gardeners should plan around a Apr 20 - May 10 last frost, while those in Southern Utah can typically plant earlier. 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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