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When to Plant Thai Basil in Wasatch County, UT

Thai basil has a distinctive anise-licorice flavor with sturdy purple stems and small leaves. It is essential in Thai, Vietnamese, and other Southeast Asian cuisines.

Wasatch County, Utah is in USDA Zone 5a. 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 86ยฐF, providing good warmth for Thai Basil during the growing season. With low rainfall, drip irrigation is essential for growing Thai Basil successfully. Mulch heavily to conserve soil moisture.

Wasatch County, UT (Zone 5a) 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) ✓ Fits season (6 days to spare)
Start indoors: Mar 16 Transplant: May 18 🍅 Harvest: Jul 13 – Sep 14
Recommended (50%) ✗ May not fit
Start indoors: Mar 31 Transplant: Jun 2 🍅 Harvest: Jul 28 – Sep 29
Safe Start (90%) ✗ May not fit
Start indoors: May 1 Transplant: Jul 3 🍅 Harvest: Aug 28 – Oct 30

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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.5″/week
You supply
0.6″/week
Watering frequency 1-2 times/week
Season total 644 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Thai Basil needs ~906 GDD — county provides 1,885 GDD Excellent fit

Thai Basil Planting Timeline โ€” Wasatch County, UT

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors March 31 Mar 31 โ€“ Apr 14
Transplant Outdoors June 2 Jun 2 โ€“ Jun 16
Direct Sow May 26 May 26 โ€“ Jun 16
Harvest July 28 Jul 28 โ€“ Sep 29

Plant 0.5" deep ยท 8" apart ยท Rows 12" apart

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

50โ€“75 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5a

Growing Season

130 days

Growing Tips for Wasatch County

Start seeds indoors or direct sow after last frost. Thai basil holds up better to heat in cooking than sweet basil. Pinch flowers to prolong leaf production.

Companion Planting

Good Companions

Avoid Planting Near

  • Rue
  • Sage

Level Up Your Garden

Frequently Asked Questions

When should I plant Thai Basil in Wasatch County, UT?

Wasatch County is in Zone 5a with an average last frost of May 19. Plan your Thai Basil planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Wasatch County, UT?

Wasatch County, Utah is in USDA Hardiness Zone 5a. The average last spring frost is May 19 and first fall frost is September 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Wasatch County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

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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: April 2026.