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When to Plant Thai Basil in Gonzales County, TX

Gonzales County, Texas Zone 9a May

Your May gardening checklist

Welcome to May in Zone 9a. These are the moves that will have the biggest impact on your growing season.

Avg. last frost February 28
Avg. first frost November 28
Soil temp (4") 62°F
Watering Low
Pest pressure High
Daylight 13.5 hrs
  1. Collect thai basil at their peak

    Check every 1–2 days. Many of these get tough or go to seed if you wait too long.

Coming up in June — start thinking about
  • 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.

Gonzales County, Texas is in USDA Zone 9a. The average last spring frost is February 28 and the first fall frost is November 28, giving you a growing season of approximately 273 days.

At an elevation of 4,385 feet, Gonzales County receives approximately 67 inches of rainfall annually with predominantly loam soil. Summer highs average 97°F, so Thai Basil may need afternoon shade and extra watering during peak heat. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Thai Basil root diseases.

Gonzales County, TX (Zone 9a) Year-round
273 days
Last Spring Frost February 28
273 growing days
First Fall Frost November 28
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Gonzales County Soil Profile

Soil Type

Loam

Soil pH

6.2-7.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (149 days to spare)
Start indoors: Jan 4 Transplant: Feb 22 🍅 Harvest: Apr 19 – Jun 21
Recommended (50%) ✓ Fits season (147 days to spare)
Start indoors: Jan 17 Transplant: Mar 7 🍅 Harvest: May 2 – Jul 4
Safe Start (90%) ✓ Fits season (138 days to spare)
Start indoors: Feb 9 Transplant: Mar 30 🍅 Harvest: May 25 – Jul 27

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 Gonzales County

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

Soil pH

Your soil pH (6.2–7.4) overlaps with Thai Basil's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.4%). 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

6
successive plantings in your 273-day season

Sow every 5.7 weeks. Last sowing by Sep 14 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.0″/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 1.5" 0" ❄️ Dormant
Feb 4.3" 2" 2.3" 🚿 Regular watering
Mar 4.3" 4.3" 0" ✅ Rainfall sufficient
Apr 4.3" 7.7" 0" ✅ Rainfall sufficient
May 4.3" 10.3" 0" ✅ Rainfall sufficient
Jun 4.3" 9.8" 0" ✅ Rainfall sufficient
Jul 4.3" 9" 0" ✅ Rainfall sufficient
Aug 4.3" 8.8" 0" ✅ Rainfall sufficient
Sep 4.3" 5.3" 0" ✅ Rainfall sufficient
Oct 4.3" 4.3" 0" ✅ Rainfall sufficient
Nov 4.3" 2.5" 1.8" 💧 Light watering
Dec 1.6" 0" ❄️ Dormant

Water needs are for active growing months only (Feb–Nov in Gonzales 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 ~1,422 GDD — county provides 6,233 GDD Excellent fit

Thai Basil Planting Timeline — Gonzales County, TX

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors January 17 Jan 17 – Jan 31
Transplant Outdoors March 7 Mar 7 – Mar 21
Direct Sow March 7 Mar 7 – Mar 28
Harvest May 2 May 2 – Jul 4

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 9a

📆 Growing Season

273 days in Gonzales County

Growing Tips for Thai Basil in Gonzales County

Direct sow Thai Basil outdoors after February 28 in Gonzales County when soil has warmed and frost danger has passed.

With summer highs reaching 97°F in Gonzales County, 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 Gonzales County, TX?

Gonzales County is in Zone 9a with an average last frost of February 28. Plan your Thai Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Gonzales County, TX?

Gonzales County, Texas is in USDA Hardiness Zone 9a. The average last spring frost is February 28 and first fall frost is November 28.

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Your Gonzales County Garden Planner — Free

A 24-page printable planner built for Gonzales County (Zone 9a). 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 Gonzales County, TX. 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.