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When to Plant Basil in Tulsa County, OK

Tulsa County, Oklahoma Zone 7b May

This month in Tulsa County, Oklahoma

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Tulsa County, Oklahoma.

Avg. last frost April 7
Avg. first frost October 26
Soil temp (4") 69°F
Watering Low
Pest pressure Moderate
Daylight 13.9 hrs
  1. Start basil under lights

    Starting these indoors now means sturdy transplants ready the moment your soil warms up.

June prep starts now
  • First harvests: basil

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Basil is a fragrant warm-season herb essential to Italian and Thai cuisines. It comes in many varieties including sweet, Thai, purple, and lemon types.

Tulsa County, Oklahoma is in USDA Zone 7b. 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 90°F, providing good warmth for Basil during the growing season.

Tulsa County, OK (Zone 7b) Long season
202 days
Last Spring Frost April 7
202 growing days
First Fall Frost October 26
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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 Basil's growing requirements.

Soil pH

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

Soil Texture

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

Organic Matter

Organic matter is moderate (3.6%). Annual compost additions will help Basil.

How to Plant Basil

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

Succession Planting 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
0.6″/week
Rainfall provides
0.6″/week
Watering frequency Only during dry spells
Season total 6 gal / 100 sq ft

Monthly Watering Guide for Basil

Basil needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.

Month Basil Needs Rainfall You Supplement Action
Jan 0.9" 0" ❄️ Dormant
Feb 1.1" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 2.6" 3.5" 0" ✅ Rainfall sufficient
May 2.6" 4.5" 0" ✅ Rainfall sufficient
Jun 2.6" 4.9" 0" ✅ Rainfall sufficient
Jul 2.6" 3.4" 0" ✅ Rainfall sufficient
Aug 2.6" 3" 0" ✅ Rainfall sufficient
Sep 2.6" 2.4" 0.2" 💧 Light watering
Oct 2.6" 1.9" 0.7" 💧 Light watering
Nov 0.9" 0" ❄️ Dormant
Dec 0.7" 0" ❄️ Dormant

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

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.

Basil needs ~1,094 GDD — county provides 3,535 GDD Excellent fit

Basil Planting Timeline — Tulsa County, OK

Basil Planting Calendar

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

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

0.6"/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

202 days in Tulsa County

Growing Tips for Basil in Tulsa County

Direct sow 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. Pinch flower buds to extend leaf production. Harvest leaves from the top down, cutting just above a leaf pair.

Companion Planting

Good Companions

Avoid Planting Near

  • Rue
  • Sage

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Basil Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let flower spikes dry brown on the plant.
Storage Store airtight; viable 5 years at 35°F, under 45% humidity.

Isolate 150 ft between varieties. Different basil species can cross.

Frequently Asked Questions

When should I plant Basil in Tulsa County, OK?

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

What planting zone is Tulsa County, OK?

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

🌱

Your Tulsa County Garden Planner — Free

A 24-page printable planner built for Tulsa 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 Tulsa County, OK. 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.