Blog

When to Plant Tomatoes in Wasatch County, UT

Wasatch County, Utah Zone 6a May

Your May planting checklist for Wasatch County, Utah

May is a pivotal month for Wasatch County, Utah gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost May 19
Avg. first frost September 26
Soil temp (4") 35°F
Watering High
Pest pressure Low
Daylight 14.2 hrs
  1. Put tomatoes seeds straight in the ground

    Thin ruthlessly once seedlings are up. Crowded roots mean smaller crops from every plant.

June will be here before you know it — start on
  • Transplants going out: tomatoes

Instant PDF download. No spam, unsubscribe any time.

Tomatoes are the most popular home garden crop, available in thousands of varieties from tiny cherries to massive beefsteaks. They are warm-season plants needing full sun.

Wasatch County, Utah is in USDA Zone 6a. The average last spring frost is May 19 and the first fall frost is September 26, giving you a growing season of approximately 130 days.

At an elevation of 8,190 feet, Wasatch County receives approximately 16.6 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Tomatoes during the growing season. With low rainfall, drip irrigation is essential for growing Tomatoes successfully. Mulch heavily to conserve soil moisture.

Wasatch County, UT (Zone 6a) Short season
130 days
Last Spring Frost May 19
130 growing days
First Fall Frost September 26

Wasatch County Soil Profile

Soil Type

Loam

Soil pH

6.6-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 9 Transplant: May 18 🍅 Harvest: Jul 20 – Sep 28
Recommended (50%) ✗ May not fit
Start indoors: Mar 24 Transplant: Jun 2 🍅 Harvest: Aug 4 – Oct 13
Safe Start (90%) ✗ May not fit
Start indoors: Apr 24 Transplant: Jul 3 🍅 Harvest: Sep 4 – Nov 13

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Wasatch County

How your county's soil matches Tomatoes's growing requirements.

Soil pH

Your soil pH (6.6–7.6) is more alkaline than Tomatoes prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Wasatch County is excellent for Tomatoes — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.9%). Annual compost additions will help Tomatoes.

How to Plant Tomatoes

0.5"
Planting Depth
24"
Between Plants
36"
Between Rows

Succession Planting Tomatoes

2
successive plantings in your 130-day season

Sow every 6.9 weeks. Last sowing by Jul 03 to harvest before frost.

Plant Water Budget

Plant needs
1.2″/week
Rainfall provides
0.5″/week
You supply
0.8″/week
Watering frequency 2-3 times/week
Season total 921 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Tomatoes

Tomatoes needs approximately 1.2 inches of water per week (5.2" per month). Here's how your county's rainfall compares month by month.

Month Tomatoes Needs Rainfall You Supplement Action
Jan 1.2" 0" ❄️ Dormant
Feb 1" 0" ❄️ Dormant
Mar 1.6" 0" ❄️ Dormant
Apr 1.6" 0" ❄️ Dormant
May 5.2" 2.1" 3.1" 🚿 Regular watering
Jun 5.2" 1.2" 4" 🚿 Regular watering
Jul 5.2" 1.2" 4" 🚿 Regular watering
Aug 5.2" 1.7" 3.5" 🚿 Regular watering
Sep 5.2" 1.2" 4" 🚿 Regular watering
Oct 1.4" 0" ❄️ Dormant
Nov 1.2" 0" ❄️ Dormant
Dec 1.1" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Wasatch County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Tomatoes Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Tomatoes needs ~1,051 GDD — county provides 1,885 GDD Excellent fit

Tomatoes Planting Timeline — Wasatch County, UT

Tomatoes Planting Calendar

Activity When Date Range
Start Indoors March 24 Mar 24 – Apr 7
Transplant Outdoors June 2 Jun 2 – Jun 16
Direct Sow May 26 May 26 – Jun 16
Harvest August 4 Aug 4 – Oct 13

Plant 0.5" deep · 24" apart · Rows 36" apart

Month-by-Month Timeline

MonthActivities
January
February
March Start Indoors
April Start Indoors
May Direct Sow
June Transplant Outdoors Direct Sow
July
August Harvest
September Harvest
October Harvest
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1.2"/week · 2-3 times/week

📅 Days to Maturity

60–85 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

130 days in Wasatch County

Growing Tips for Tomatoes in Wasatch County

Direct sow Tomatoes outdoors after May 19 in Wasatch County when soil has warmed and frost danger has passed.

Common pests for Tomatoes in this region include tomato hornworm and aphids. Use row covers early in the season and inspect plants weekly.

Wasatch County receives only 17" of rain annually. Tomatoes needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

General growing tips

Start seeds indoors 6-8 weeks before last frost. Bury transplants deep to encourage rooting along the stem. Provide consistent moisture to prevent blossom end rot and cracking.

Recommended Tomatoes Varieties for Wasatch County

Choose determinate, early-maturing varieties for your short season

Early Girl (52d) Stupice (55d) Glacier (55d) Sub Arctic Plenty (45d)

Companion Planting

Good Companions

Avoid Planting Near

  • Cabbage
  • Fennel
  • Potatoes

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Tomatoes Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Scoop seeds from ripe fruit; ferment 2-3 days to remove gel coating.
Storage Store airtight; viable 4-6 years at 35°F, under 45% humidity.

Isolate 25 ft between varieties for purity. Use open-pollinated varieties for true-to-type seeds.

Frequently Asked Questions

When should I plant Tomatoes in Wasatch County, UT?

Wasatch County is in Zone 6a with an average last frost of May 19. Plan your Tomatoes planting based on this frost date — see the calendar above for exact timing.

What planting zone is Wasatch County, UT?

Wasatch County, Utah is in USDA Hardiness Zone 6a. The average last spring frost is May 19 and first fall frost is September 26.

🌱

Your Wasatch County Garden Planner — Free

A 24-page printable planner built for Wasatch County (Zone 6a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Wasatch County, UT. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.