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When to Plant Basil in Hamilton County, TX

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.

Hamilton County, Texas is in USDA Zone 8a. The average last spring frost is March 18 and the first fall frost is November 12, giving you a growing season of approximately 239 days.

At an elevation of 4,378 feet, Hamilton County receives approximately 65.2 inches of rainfall annually with predominantly clay soil. Summer highs average 93ยฐF, providing good warmth for Basil during the growing season. Clay soil retains moisture well for Basil, but amend with compost to improve drainage and prevent root rot. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Basil root diseases.

Hamilton County, TX (Zone 8a) Long season
239 days
Last Spring Frost March 18
239 growing days
First Fall Frost November 12

Hamilton County Soil Profile

Soil Type

Clay

Soil pH

6.9-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (111 days to spare)
Start indoors: Jan 17 Transplant: Mar 21 🍅 Harvest: May 16 – Jul 18
Recommended (50%) ✓ Fits season (106 days to spare)
Start indoors: Jan 28 Transplant: Apr 1 🍅 Harvest: May 27 – Jul 29
Safe Start (90%) ✓ Fits season (101 days to spare)
Start indoors: Feb 21 Transplant: Apr 25 🍅 Harvest: Jun 20 – Aug 22

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 Hamilton County

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

Soil pH

Your soil pH (6.9โ€“8.2) is more alkaline than Basil prefers (6.0โ€“7.0). Add sulfur or peat moss to lower pH.

Soil Texture

Your clay soil in Hamilton County is workable for Basil. Add compost annually to improve structure.

Organic Matter

Organic matter is moderate (3.4%). Annual compost additions will help Basil.

How to Plant Basil

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

Succession Planting Basil

5
successive plantings in your 239-day season

Sow every 5.7 weeks. Last sowing by Aug 29 to harvest before frost.

Plant Water Budget

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

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

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 โ€” 1.6" 0" โ„๏ธ Dormant
Feb โ€” 2.2" 0" โ„๏ธ Dormant
Mar 2.6" 3.8" 0" โœ… Rainfall sufficient
Apr 2.6" 6.9" 0" โœ… Rainfall sufficient
May 2.6" 9.7" 0" โœ… Rainfall sufficient
Jun 2.6" 10.8" 0" โœ… Rainfall sufficient
Jul 2.6" 8.7" 0" โœ… Rainfall sufficient
Aug 2.6" 8.5" 0" โœ… Rainfall sufficient
Sep 2.6" 5.7" 0" โœ… Rainfall sufficient
Oct 2.6" 3.7" 0" โœ… Rainfall sufficient
Nov 2.6" 2.2" 0.4" ๐Ÿ’ง Light watering
Dec โ€” 1.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Marโ€“Nov in Hamilton County). Supplement amounts are based on average rainfall โ€” 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" 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.

Basil needs ~1,234 GDD — county provides 4,720 GDD Excellent fit

Basil Planting Timeline โ€” Hamilton County, TX

Basil Planting Calendar

Activity When Date Range
Start Indoors January 28 Jan 28 โ€“ Feb 11
Transplant Outdoors April 1 Apr 1 โ€“ Apr 15
Direct Sow March 25 Mar 25 โ€“ Apr 15
Harvest May 27 May 27 โ€“ Jul 29

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.6"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

50โ€“75 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_alkaline

๐Ÿ—บ๏ธ USDA Zone

Zone 8a

๐Ÿ“† Growing Season

239 days in Hamilton County

Growing Tips for Basil in Hamilton County

Direct sow Basil outdoors after March 18 in Hamilton County when soil has warmed and frost danger has passed.

With Hamilton County's clay soil (40% clay), work in 3-4 inches of compost before planting Basil. Avoid tilling when soil is wet to prevent compaction.

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.

Recommended Basil Varieties for Hamilton County

Downy mildew-resistant basil for your humid climate

Prospera (DM-resistant) Amazel Eleonora

Companion Planting

Good Companions

Avoid Planting Near

  • Rue
  • Sage

Check more plant combinations with our Companion Planting Checker →

๐ŸŒพ 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 35ยฐF, under 45% humidity.

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

Frequently Asked Questions

When should I plant Basil in Hamilton County, TX?

Hamilton County is in Zone 8a with an average last frost of March 18. Plan your Basil planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Hamilton County, TX?

Hamilton County, Texas is in USDA Hardiness Zone 8a. The average last spring frost is March 18 and first fall frost is November 12.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Hamilton County gardeners in Zone 8a 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 Hamilton County, TX. Local conditions may vary. Last updated: April 2026.