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When to Plant Thai Basil in Sevier County, TN

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.

Sevier County, Tennessee is in USDA Zone 7a. The average last spring frost is April 17 and the first fall frost is October 21, giving you a growing season of approximately 187 days.

At an elevation of 2,536 feet, Sevier County receives approximately 45 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88ยฐF, providing good warmth for Thai Basil during the growing season.

Sevier County, TN (Zone 7a) Moderate season
187 days
Last Spring Frost April 17
187 growing days
First Fall Frost October 21

Sevier County Soil Profile

Soil Type

Silt Loam

Soil pH

5.6-6.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (58 days to spare)
Start indoors: Feb 19 Transplant: Apr 23 🍅 Harvest: Jun 18 – Aug 20
Recommended (50%) ✓ Fits season (54 days to spare)
Start indoors: Feb 27 Transplant: May 1 🍅 Harvest: Jun 26 – Aug 28
Safe Start (90%) ✓ Fits season (49 days to spare)
Start indoors: Mar 15 Transplant: May 17 🍅 Harvest: Jul 12 – Sep 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.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Thai Basil needs ~1,000 GDD — county provides 2,992 GDD Excellent fit

Thai Basil Planting Timeline โ€” Sevier County, TN

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors February 27 Feb 27 โ€“ Mar 13
Transplant Outdoors May 1 May 1 โ€“ May 15
Direct Sow April 24 Apr 24 โ€“ May 15
Harvest June 26 Jun 26 โ€“ Aug 28

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

Month-by-Month Timeline

MonthActivities
January โ€”
February Start Indoors
March Start Indoors
April Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Harvest
August Harvest
September โ€”
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 7a

Growing Season

187 days

Growing Tips for Sevier 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 Sevier County, TN?

Sevier County is in Zone 7a with an average last frost of April 17. Plan your Thai Basil planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Sevier County, TN?

Sevier County, Tennessee is in USDA Hardiness Zone 7a. The average last spring frost is April 17 and first fall frost is October 21.

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Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Sevier County gardeners in Zone 7a 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 Sevier County, TN. Local conditions may vary. Last updated: April 2026.