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When to Plant Thai Basil in Oklahoma County, OK

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.

Oklahoma County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 2 and the first fall frost is November 5, giving you a growing season of approximately 217 days.

At an elevation of 739 feet, Oklahoma County receives approximately 26.6 inches of rainfall annually with predominantly loam soil. Summer highs average 88ยฐF, providing good warmth for Thai Basil during the growing season.

Oklahoma County, OK (Zone 7a) Long season
217 days
Last Spring Frost April 2
217 growing days
First Fall Frost November 5

Oklahoma County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (89 days to spare)
Start indoors: Jan 31 Transplant: Apr 4 🍅 Harvest: May 30 – Aug 1
Recommended (50%) ✓ Fits season (84 days to spare)
Start indoors: Feb 12 Transplant: Apr 16 🍅 Harvest: Jun 11 – Aug 13
Safe Start (90%) ✓ Fits season (87 days to spare)
Start indoors: Feb 25 Transplant: Apr 29 🍅 Harvest: Jun 24 – Aug 26

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 Oklahoma County

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

Soil pH

Your soil pH (6.5โ€“7.6) is more alkaline than Thai Basil prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Oklahoma County is excellent for Thai Basil โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.4%). 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

5
successive plantings in your 217-day season

Sow every 5.7 weeks. Last sowing by Aug 22 to harvest before frost.

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 1,124 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

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 โ€” 0.7" 0" โ„๏ธ Dormant
Feb โ€” 1" 0" โ„๏ธ Dormant
Mar โ€” 1.8" 0" โ„๏ธ Dormant
Apr 4.3" 2.9" 1.4" ๐Ÿ’ง Light watering
May 4.3" 4.3" 0" โœ… Rainfall sufficient
Jun 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Jul 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Aug 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Sep 4.3" 2.5" 1.8" ๐Ÿ’ง Light watering
Oct 4.3" 1.4" 2.9" ๐Ÿšฟ Regular watering
Nov 4.3" 0.9" 3.4" ๐Ÿšฟ Regular watering
Dec โ€” 0.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Nov in Oklahoma County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,000 GDD — county provides 3,472 GDD Excellent fit

Thai Basil Planting Timeline โ€” Oklahoma County, OK

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors February 12 Feb 12 โ€“ Feb 26
Transplant Outdoors April 16 Apr 16 โ€“ Apr 30
Direct Sow April 9 Apr 9 โ€“ Apr 30
Harvest June 11 Jun 11 โ€“ Aug 13

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

1"/week ยท 1-2 times/week

๐Ÿ“… Days to Maturity

50โ€“75 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

217 days in Oklahoma County

Growing Tips for Thai Basil in Oklahoma County

Direct sow Thai Basil outdoors after April 02 in Oklahoma 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 Oklahoma County, OK?

Oklahoma County is in Zone 7a with an average last frost of April 2. Plan your Thai Basil planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Oklahoma County, OK?

Oklahoma County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 2 and first fall frost is November 5.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Oklahoma County gardeners in Zone 7a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Oklahoma County, OK. Local conditions may vary. Last updated: April 2026.