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When to Plant Thai Basil in Lake County, OR

Lake County, Oregon Zone 6b May

May to-do list for Lake County, Oregon

Your garden in Lake County, Oregon is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost June 16
Avg. first frost September 7
Soil temp (4") 58°F
Watering Critical
Pest pressure Low
Daylight 14.4 hrs
June prep starts now
  • Transplants going out: thai basil
  • Direct-sowing: 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.

Lake County, Oregon is in USDA Zone 6b. The average last spring frost is June 16 and the first fall frost is September 7, giving you a growing season of approximately 83 days.

At an elevation of 1,236 feet, Lake County receives approximately 12.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Thai Basil during the growing season. With low rainfall, drip irrigation is essential for growing Thai Basil successfully. Mulch heavily to conserve soil moisture.

Lake County, OR (Zone 6b) Very short season
83 days
Last Spring Frost June 16
83 growing days
First Fall Frost September 7
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Lake County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 14 Transplant: Jun 16 🍅 Harvest: Aug 11 – Oct 13
Recommended (50%) ✗ May not fit
Start indoors: Apr 28 Transplant: Jun 30 🍅 Harvest: Aug 25 – Oct 27
Safe Start (90%) ✗ May not fit
Start indoors: May 8 Transplant: Jul 10 🍅 Harvest: Sep 4 – Nov 6

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 Lake County

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

Soil pH

Your soil pH (5.7–6.4) overlaps with Thai Basil's range (6.0–7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.4%) — Thai Basil will thrive.

How to Plant Thai Basil

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

Plant 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 260 gal / 100 sq ft

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 2" 0" ❄️ Dormant
Feb 1.3" 0" ❄️ Dormant
Mar 1.3" 0" ❄️ Dormant
Apr 0.8" 0" ❄️ Dormant
May 0.7" 0" ❄️ Dormant
Jun 4.3" 0.5" 3.8" 🚿 Regular watering
Jul 4.3" 0.2" 4.1" 🚿 Regular watering
Aug 4.3" 0.2" 4.1" 🚿 Regular watering
Sep 4.3" 0.5" 3.8" 🚿 Regular watering
Oct 1.2" 0" ❄️ Dormant
Nov 1.9" 0" ❄️ Dormant
Dec 2.1" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Lake 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 ~1,000 GDD — county provides 1,328 GDD Excellent fit

Thai Basil Planting Timeline — Lake County, OR

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors April 28 Apr 28 – May 12
Transplant Outdoors June 30 Jun 30 – Jul 14
Direct Sow June 23 Jun 23 – Jul 14
Harvest August 25 Aug 25 – Oct 27

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

Month-by-Month Timeline

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

🗺️ USDA Zone

Zone 6b

📆 Growing Season

83 days in Lake County

Growing Tips for Thai Basil in Lake County

Direct sow Thai Basil outdoors after June 16 in Lake County when soil has warmed and frost danger has passed.

Lake County receives only 13" of rain annually. Thai Basil needs consistent moisture — install drip irrigation or water deeply 2-3 times per week.

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 Lake County, OR?

Lake County is in Zone 6b with an average last frost of June 16. Plan your Thai Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Lake County, OR?

Lake County, Oregon is in USDA Hardiness Zone 6b. The average last spring frost is June 16 and first fall frost is September 7.

🌱

Your Lake County Garden Planner — Free

A 24-page printable planner built for Lake County (Zone 6b). 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 Lake County, OR. 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.