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When to plant Thai Basil in Simpson County County,

Aim to plant Thai Basil in Simpson County County on or after April 13; the window stays open through May 4. Simpson County County's 206-day frost-free season gives you enough for a full main crop and a short fall succession.

When to Plant Thai Basil in Simpson County, KY

Simpson County, Kentucky Zone 7a June

Your June gardening checklist

Here's what deserves your attention in Simpson County, Kentucky this month. Everything below is tailored to Zone 7a and timed around your local frost dates.

Avg. last frost April 6
Avg. first frost October 29
Soil temp (4") 65°F
Watering Low
Pest pressure High
Daylight 14.5 hrs
  1. Harvest thai basil as they ripen

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

Looking ahead to July
  • 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.

Simpson County, Kentucky is in USDA Zone 7a. The average last spring frost is April 6 and the first fall frost is October 29, giving you a growing season of approximately 206 days.

At an elevation of 3,996 feet, Simpson County receives approximately 49.6 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89°F, providing good warmth for Thai Basil during the growing season.

Simpson County, KY (Zone 7a) Long season
206 days
Last Spring Frost April 6
206 growing days
First Fall Frost October 29
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Simpson County Soil Profile

Soil Type

Silt Loam

Soil pH

5.5-6.7

Drainage

Well Drained

Thai Basil Planting Risk Windows

Early Start (70% safe) ✓ Fits season (74 days to spare)
Start indoors: Feb 9 Transplant: Apr 13 🍅 Harvest: Jun 8 – Aug 10
Recommended (50%) ✓ Fits season (73 days to spare)
Start indoors: Feb 16 Transplant: Apr 20 🍅 Harvest: Jun 15 – Aug 17
Safe Start (90%) ✓ Fits season (73 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 Simpson County

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

Soil pH

Your soil pH (5.5–6.7) overlaps with Thai Basil's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Drainage

Drainage is adequate for Thai Basil.

Organic Matter

Organic matter is moderate (2.5%). 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 206-day season

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

Thai Basil Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 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 4.1" 0" ❄️ Dormant
Feb 3.9" 0" ❄️ Dormant
Mar 3.9" 0" ❄️ Dormant
Apr 4.3" 4" 0.3" 💧 Light watering
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 4.6" 0" ✅ Rainfall sufficient
Jul 4.3" 5.6" 0" ✅ Rainfall sufficient
Aug 4.3" 4.9" 0" ✅ Rainfall sufficient
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 2.9" 1.4" 💧 Light watering
Nov 4" 0" ❄️ Dormant
Dec 4.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Simpson 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 ~1,047 GDD — county provides 3,450 GDD Excellent fit

Thai Basil Planting Timeline — Simpson County, KY

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors February 16 Feb 16 – Mar 2
Transplant Outdoors April 20 Apr 20 – May 4
Direct Sow April 13 Apr 13 – May 4
Harvest June 15 Jun 15 – Aug 17

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 · Natural rainfall sufficient

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: acceptable

🗺️ USDA Zone

Zone 7a

📆 Growing Season

206 days in Simpson County

Growing Tips for Thai Basil in Simpson County

Direct sow Thai Basil outdoors after April 06 in Simpson 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 Simpson County, KY?

Simpson County is in Zone 7a with an average last frost of April 6. Plan your Thai Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Simpson County, KY?

Simpson County, Kentucky is in USDA Hardiness Zone 7a. The average last spring frost is April 6 and first fall frost is October 29.

When should I plant Thai Basil in Simpson County County, ?

In Simpson County County, , plant Thai Basil after the last frost (around April 6) and before the first frost (around October 29). Best results when soil holds above 50°F.

What growing zone is Simpson County County, for Thai Basil?

Simpson County County sits in USDA Zone 7a. Thai Basil grows reliably in zones 4a through 11b, so it's a good fit here.

Can Thai Basil grow in Simpson County County's climate?

Yes — Thai Basil grows well in Simpson County County's temperate climate. Simpson County County averages a 206-day frost-free season, with last frost around April 6 and first frost around October 29.

🌱

Your Simpson County Garden Planner — Free

A 22-page printable planner built for Simpson County (Zone 7a). 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 Simpson County, KY. Local conditions may vary. Last updated: June 2026.

Sources & credits

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