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When to Plant Thai Basil in Tulsa 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.

Tulsa County, Oklahoma is in USDA Zone 7a. The average last spring frost is April 7 and the first fall frost is October 26, giving you a growing season of approximately 202 days.

At an elevation of 752 feet, Tulsa County receives approximately 28.7 inches of rainfall annually with predominantly loam soil. Summer highs average 90ยฐF, providing good warmth for Thai Basil during the growing season.

Tulsa County, OK (Zone 7a) Long season
202 days
Last Spring Frost April 7
202 growing days
First Fall Frost October 26

Tulsa County Soil Profile

Soil Type

Loam

Soil pH

6.8-7.1

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (67 days to spare)
Start indoors: Feb 12 Transplant: Apr 16 🍅 Harvest: Jun 11 – Aug 13
Recommended (50%) ✓ Fits season (69 days to spare)
Start indoors: Feb 17 Transplant: Apr 21 🍅 Harvest: Jun 16 – Aug 18
Safe Start (90%) ✓ Fits season (69 days to spare)
Start indoors: Mar 6 Transplant: May 8 🍅 Harvest: Jul 3 – Sep 4

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 Tulsa County

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

Soil pH

Your soil pH (6.8โ€“7.1) overlaps with Thai Basil's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). 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 202-day season

Sow every 5.7 weeks. Last sowing by Aug 12 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.6″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 725 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 โ€” 0.9" 0" โ„๏ธ Dormant
Feb โ€” 1.1" 0" โ„๏ธ Dormant
Mar โ€” 1.7" 0" โ„๏ธ Dormant
Apr 4.3" 3.5" 0.8" ๐Ÿ’ง Light watering
May 4.3" 4.5" 0" โœ… Rainfall sufficient
Jun 4.3" 4.9" 0" โœ… Rainfall sufficient
Jul 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Aug 4.3" 3" 1.3" ๐Ÿ’ง Light watering
Sep 4.3" 2.4" 1.9" ๐Ÿ’ง Light watering
Oct 4.3" 1.9" 2.4" ๐Ÿšฟ Regular watering
Nov โ€” 0.9" 0" โ„๏ธ Dormant
Dec โ€” 0.7" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Tulsa 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 ~1,094 GDD — county provides 3,535 GDD Excellent fit

Thai Basil Planting Timeline โ€” Tulsa County, OK

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors February 17 Feb 17 โ€“ Mar 3
Transplant Outdoors April 21 Apr 21 โ€“ May 5
Direct Sow April 14 Apr 14 โ€“ May 5
Harvest June 16 Jun 16 โ€“ Aug 18

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 Transplant Outdoors Direct Sow
May Transplant Outdoors Direct Sow
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: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 7a

๐Ÿ“† Growing Season

202 days in Tulsa County

Growing Tips for Thai Basil in Tulsa County

Direct sow Thai Basil outdoors after April 07 in Tulsa 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 Tulsa County, OK?

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

What planting zone is Tulsa County, OK?

Tulsa County, Oklahoma is in USDA Hardiness Zone 7a. The average last spring frost is April 7 and first fall frost is October 26.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Tulsa 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 Tulsa County, OK. Local conditions may vary. Last updated: April 2026.