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When to Plant Thai Basil in Davidson County, TN

Davidson County, Tennessee Zone 7b May

This month in Davidson County, Tennessee

We've pulled the most time-sensitive tasks for Davidson County, Tennessee this May and put them front and centre. Tackle them in order.

Avg. last frost April 5
Avg. first frost October 29
Soil temp (4") 62°F
Watering Moderate
Pest pressure Moderate
Daylight 13.9 hrs
  1. Time to start thai basil inside

    Label every cell. You will absolutely forget which is which otherwise.

A few tasks this May that'll pay off in June
  • First harvests: thai basil

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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.

Davidson County, Tennessee is in USDA Zone 7b. The average last spring frost is April 5 and the first fall frost is October 29, giving you a growing season of approximately 207 days.

At an elevation of 2,344 feet, Davidson County receives approximately 40.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Thai Basil during the growing season.

Davidson County, TN (Zone 7b) Long season
207 days
Last Spring Frost April 5
207 growing days
First Fall Frost October 29
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Davidson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.2-7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (75 days to spare)
Start indoors: Feb 8 Transplant: Apr 12 🍅 Harvest: Jun 7 – Aug 9
Recommended (50%) ✓ Fits season (74 days to spare)
Start indoors: Feb 15 Transplant: Apr 19 🍅 Harvest: Jun 14 – Aug 16
Safe Start (90%) ✓ Fits season (74 days to spare)
Start indoors: Mar 1 Transplant: May 3 🍅 Harvest: Jun 28 – Aug 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.

Soil Compatibility in Davidson County

How your county's soil matches Thai Basil's growing requirements.

Soil pH

Your soil pH (5.2–7.0) overlaps with Thai Basil's range (6.0–7.0), though not a perfect match.

Soil Texture

The silt loam soil in Davidson County is excellent for Thai Basil — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (2.6%). Annual compost additions will help Thai Basil.

How to Plant Thai Basil

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Thai Basil

4
successive plantings in your 207-day season

Sow every 5.7 weeks. Last sowing by Aug 15 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 328 gal / 100 sq ft

Monthly Watering Guide for Thai Basil

Thai Basil needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Thai Basil Needs Rainfall You Supplement Action
Jan 2.9" 0" ❄️ Dormant
Feb 3.1" 0" ❄️ Dormant
Mar 4.4" 0" ❄️ Dormant
Apr 4.3" 3.2" 1.1" 💧 Light watering
May 4.3" 2.9" 1.4" 💧 Light watering
Jun 4.3" 3.9" 0.4" 💧 Light watering
Jul 4.3" 4.6" 0" ✅ Rainfall sufficient
Aug 4.3" 3.6" 0.7" 💧 Light watering
Sep 4.3" 3.3" 1" 💧 Light watering
Oct 4.3" 2.3" 2" 💧 Light watering
Nov 2.6" 0" ❄️ Dormant
Dec 3.5" 0" ❄️ Dormant

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

Thai Basil 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.

Thai Basil needs ~1,141 GDD — county provides 3,777 GDD Excellent fit

Thai Basil Planting Timeline — Davidson County, TN

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors February 15 Feb 15 – Mar 1
Transplant Outdoors April 19 Apr 19 – May 3
Direct Sow April 12 Apr 12 – May 3
Harvest June 14 Jun 14 – Aug 16

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7b

📆 Growing Season

207 days in Davidson County

Growing Tips for Thai Basil in Davidson County

Direct sow Thai Basil outdoors after April 05 in Davidson County when soil has warmed and frost danger has passed.

General growing tips

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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Thai Basil in Davidson County, TN?

Davidson County is in Zone 7b with an average last frost of April 5. Plan your Thai Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Davidson County, TN?

Davidson County, Tennessee is in USDA Hardiness Zone 7b. The average last spring frost is April 5 and first fall frost is October 29.

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Your Davidson County Garden Planner — Free

A 24-page printable planner built for Davidson County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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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 Davidson County, TN. 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.