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When to Plant Thai Basil in Orleans Parish, LA

Orleans Parish, Louisiana Zone 9b May

This month in Orleans Parish, Louisiana

Each item below is timed to Orleans Parish, Louisiana's frost dates and soil temperatures. Skip nothing, stress about nothing.

Avg. last frost February 20
Avg. first frost November 23
Soil temp (4") 79°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Bring in the thai basil

    Don't tug. Use scissors or pruners for clean cuts — torn stems invite disease.

June will be here before you know it — start on
  • 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.

Orleans Parish, Louisiana is in USDA Zone 9b. The average last spring frost is February 20 and the first fall frost is November 23, giving you a growing season of approximately 276 days.

At an elevation of 489 feet, Orleans Parish receives approximately 50.1 inches of rainfall annually with predominantly sandy loam soil. Summer highs average 101°F, so Thai Basil may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Thai Basil will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Thai Basil root diseases.

Orleans Parish, LA (Zone 9b) Year-round
276 days
Last Spring Frost February 20
276 growing days
First Fall Frost November 23
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Orleans Parish Soil Profile

Soil Type

Sandy Loam

Soil pH

5-6.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (163 days to spare)
Start indoors: Dec 19 Transplant: Feb 6 🍅 Harvest: Apr 3 – Jun 5
Recommended (50%) ✓ Fits season (150 days to spare)
Start indoors: Jan 9 Transplant: Feb 27 🍅 Harvest: Apr 24 – Jun 26
Safe Start (90%) ✓ Fits season (137 days to spare)
Start indoors: Feb 16 Transplant: Apr 6 🍅 Harvest: Jun 1 – Aug 3

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 Orleans Parish

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

Soil pH

Your soil pH (5.0–6.2) is more acidic than Thai Basil prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

Sandy soil in Orleans Parish warms quickly in spring but drains fast. Thai Basil will need more frequent watering and regular compost additions to retain nutrients.

Drainage

Drainage is adequate for Thai Basil.

Organic Matter

Organic matter is low (1.9%). Add 2-3 inches of compost before planting Thai Basil.

How to Plant Thai Basil

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

Succession Planting Thai Basil

6
successive plantings in your 276-day season

Sow every 5.7 weeks. Last sowing by Sep 09 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 4.2" 0" ❄️ Dormant
Feb 4.3" 4.2" 0.1" 💧 Light watering
Mar 4.3" 4.4" 0" ✅ Rainfall sufficient
Apr 4.3" 3.9" 0.4" 💧 Light watering
May 4.3" 4.4" 0" ✅ Rainfall sufficient
Jun 4.3" 4.9" 0" ✅ Rainfall sufficient
Jul 4.3" 4.3" 0" ✅ Rainfall sufficient
Aug 4.3" 5.1" 0" ✅ Rainfall sufficient
Sep 4.3" 3.6" 0.7" 💧 Light watering
Oct 4.3" 3.4" 0.9" 💧 Light watering
Nov 4.3" 3.8" 0.5" 💧 Light watering
Dec 3.9" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Orleans Parish). 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 ~1,609 GDD — county provides 7,132 GDD Excellent fit

Thai Basil Planting Timeline — Orleans Parish, LA

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors January 9 Jan 9 – Jan 23
Transplant Outdoors February 27 Feb 27 – Mar 13
Direct Sow February 27 Feb 27 – Mar 20
Harvest April 24 Apr 24 – Jun 26

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

Month-by-Month Timeline

MonthActivities
January Start Indoors
February Transplant Outdoors Direct Sow
March Transplant Outdoors Direct Sow
April Harvest
May Harvest
June Harvest
July
August
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: too_acidic

🗺️ USDA Zone

Zone 9b

📆 Growing Season

276 days in Orleans Parish

Growing Tips for Thai Basil in Orleans Parish

Direct sow Thai Basil outdoors after February 20 in Orleans Parish when soil has warmed and frost danger has passed.

Sandy soil in Orleans Parish dries quickly — mulch Thai Basil with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.

With summer highs reaching 101°F in Orleans Parish, provide afternoon shade for Thai Basil and water deeply in the morning.

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 Orleans Parish, LA?

Orleans Parish is in Zone 9b with an average last frost of February 20. Plan your Thai Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Orleans Parish, LA?

Orleans Parish, Louisiana is in USDA Hardiness Zone 9b. The average last spring frost is February 20 and first fall frost is November 23.

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Your Orleans Parish Garden Planner — Free

A 24-page printable planner built for Orleans Parish (Zone 9b). 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 Orleans Parish, LA. 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.