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When to Plant Thai Basil in Woodford County, IL

Woodford County, Illinois Zone 5a April

This month in Woodford County, Illinois

Your garden in Woodford County, Illinois is working on a schedule, even when you're not. Here's where you should be this April.

Avg. last frost April 23
Avg. first frost October 17
Soil temp (4") 47°F
Watering Low
Pest pressure Low
Daylight 13.1 hrs
  1. Put thai basil seeds straight in the ground

    Mark the row. Birds and stray feet both have opinions about unmarked beds.

Get ahead of May
  • Transplants going out: 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.

Woodford County, Illinois is in USDA Zone 5a. The average last spring frost is April 23 and the first fall frost is October 17, giving you a growing season of approximately 177 days.

At an elevation of 582 feet, Woodford County receives approximately 41.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84°F, so choose short-season varieties of Thai Basil to ensure they mature before fall.

Woodford County, IL (Zone 5a) Moderate season
177 days
Last Spring Frost April 23
177 growing days
First Fall Frost October 17

Woodford County Soil Profile

Soil Type

Silt Loam

Soil pH

6-6.9

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (46 days to spare)
Start indoors: Feb 25 Transplant: Apr 29 🍅 Harvest: Jun 24 – Aug 26
Recommended (50%) ✓ Fits season (44 days to spare)
Start indoors: Mar 5 Transplant: May 7 🍅 Harvest: Jul 2 – Sep 3
Safe Start (90%) ✓ Fits season (44 days to spare)
Start indoors: Mar 18 Transplant: May 20 🍅 Harvest: Jul 15 – Sep 16

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 Woodford County

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

Soil pH

Your soil pH (6.0–6.9) is within Thai Basil's preferred range (6.0–7.0).

Soil Texture

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

Organic Matter

Organic matter is excellent (4.2%) — Thai Basil will thrive.

How to Plant Thai Basil

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

Succession Planting Thai Basil

4
successive plantings in your 177-day season

Sow every 5.7 weeks. Last sowing by Aug 03 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 32 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 1.6" 0" ❄️ Dormant
Feb 1.6" 0" ❄️ Dormant
Mar 2.7" 0" ❄️ Dormant
Apr 4.3" 4.3" 0" ✅ Rainfall sufficient
May 4.3" 4.5" 0" ✅ Rainfall sufficient
Jun 4.3" 5.5" 0" ✅ Rainfall sufficient
Jul 4.3" 4.5" 0" ✅ Rainfall sufficient
Aug 4.3" 4.6" 0" ✅ Rainfall sufficient
Sep 4.3" 4" 0.3" 💧 Light watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 2.4" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Woodford 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 ~812 GDD — county provides 2,301 GDD Excellent fit

Thai Basil Planting Timeline — Woodford County, IL

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors March 5 Mar 5 – Mar 19
Transplant Outdoors May 7 May 7 – May 21
Direct Sow April 30 Apr 30 – May 21
Harvest July 2 Jul 2 – Sep 3

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

Month-by-Month Timeline

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

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: ideal

🗺️ USDA Zone

Zone 5a

📆 Growing Season

177 days in Woodford County

Growing Tips for Thai Basil in Woodford County

Direct sow Thai Basil outdoors after April 23 in Woodford 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 Woodford County, IL?

Woodford County is in Zone 5a with an average last frost of April 23. Plan your Thai Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Woodford County, IL?

Woodford County, Illinois is in USDA Hardiness Zone 5a. The average last spring frost is April 23 and first fall frost is October 17.

🌱

Your Woodford County Garden Planner — Free

A 24-page printable planner built for Woodford County (Zone 5a). 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 Woodford County, IL. Local conditions may vary. Last updated: April 2026.

Sources & credits

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