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When to plant Thai Basil in Proberta, CA

Proberta's climate puts the Thai Basil spring window between March 13 and April 3. aim for a steady week of warm soil before planting.

When to Plant Thai Basil in Proberta, CA

Tehama County, California Zone 9b June

Your June gardening checklist

June is a pivotal month for Tehama County, California gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost March 6
Avg. first frost November 28
Soil temp (4") 81°F
Watering Critical
Pest pressure High
Daylight 14.8 hrs

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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.

Proberta, California is in USDA Zone 9b. The average last spring frost is March 6 and the first fall frost is November 28, giving you a growing season of approximately 267 days.

At an elevation of 78 feet, Tehama County receives approximately 44 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Thai Basil to ensure they mature before fall.

Proberta, CA (Zone 9b) Long season
267 days
Last Spring Frost March 6
267 growing days
First Fall Frost November 28

Proberta Soil Profile

Soil Type

Loam

Soil pH

6.8-7.6

Drainage

Well Drained

Thai Basil Planting Risk Windows

Early Start (70% safe) ✓ Fits season (144 days to spare)
Start indoors: Jan 12 Transplant: Mar 2 🍅 Harvest: Apr 27 – Jun 29
Recommended (50%) ✓ Fits season (141 days to spare)
Start indoors: Jan 23 Transplant: Mar 13 🍅 Harvest: May 8 – Jul 10
Safe Start (90%) ✓ Fits season (119 days to spare)
Start indoors: Mar 7 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 Proberta

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

Soil pH

Your soil pH (6.8–7.6) is more alkaline than Thai Basil prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.9%). 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 267-day season

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

Thai Basil Water Budget

Plant needs
1.0″/week
Rainfall provides
0.7″/week
You supply
0.4″/week
Watering frequency 1-2 times/week
Season total 878 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 10.2" 0" ❄️ Dormant
Feb 8.5" 0" ❄️ Dormant
Mar 4.3" 7" 0" ✅ Rainfall sufficient
Apr 4.3" 3.5" 0.8" 💧 Light watering
May 4.3" 1.3" 3" 🚿 Regular watering
Jun 4.3" 0.2" 4.1" 🚿 Regular watering
Jul 4.3" 0" 4.3" 🚿 Regular watering
Aug 4.3" 0" 4.3" 🚿 Regular watering
Sep 4.3" 0.4" 3.9" 🚿 Regular watering
Oct 4.3" 1.8" 2.5" 🚿 Regular watering
Nov 4.3" 4.2" 0.1" 💧 Light watering
Dec 6.9" 0" ❄️ Dormant

Water needs are for active growing months only (Mar–Nov in Tehama 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 ~719 GDD — county provides 3,070 GDD Excellent fit

Thai Basil Planting Timeline — Proberta, CA

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors January 23 Jan 23 – Feb 6
Transplant Outdoors March 13 Mar 13 – Mar 27
Direct Sow March 13 Mar 13 – Apr 3
Harvest May 8 May 8 – Jul 10

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · 1-2 times/week

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 9b

📆 Growing Season

267 days in Tehama County

Growing Tips for Thai Basil in Proberta

Direct sow Thai Basil outdoors after March 06 in Tehama 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 →

When should I plant Thai Basil in Proberta, CA?

In Proberta, CA, plant Thai Basil after the last frost (around March 6) and before the first frost (around November 28). Best results when soil holds above 50°F.

What growing zone is Proberta, CA for Thai Basil?

Proberta sits in USDA Zone 9b. Thai Basil grows reliably in zones 4a through 11b, so it's a good fit here.

Can Thai Basil grow in Proberta's climate?

Yes — Thai Basil grows well in Proberta's temperate climate. Proberta averages a 267-day frost-free season, with last frost around March 6 and first frost around November 28.

🌱

Your Tehama County Garden Planner — Free

A 22-page printable planner built for Tehama County (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 Tehama County, CA. Local conditions may vary. Last updated: July 2026.