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When to Plant Thai Basil in Lake County, OR

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 5b. 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 88ยฐF, 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 5b) Very short season
83 days
Last Spring Frost June 16
83 growing days
First Fall Frost September 7

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.

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
Thai Basil needs ~1,000 GDD — county provides 1,328 GDD Excellent fit

Thai Basil Planting Timeline โ€” Lake County, OR

Thai Basil Planting Calendar

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

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Full Sun (6-8+ hours)

Water

Moderate โ€” regular watering

Days to Maturity

50โ€“75 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5b

Growing Season

83 days

Growing Tips for Lake County

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

Level Up Your Garden

Frequently Asked Questions

When should I plant Thai Basil in Lake County, OR?

Lake County is in Zone 5b with an average last frost of June 16. Plan your Thai Basil planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Lake County, OR?

Lake County, Oregon is in USDA Hardiness Zone 5b. The average last spring frost is June 16 and first fall frost is September 7.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Lake County gardeners in Zone 5b organize planting dates, track what's growing, and never miss a planting window.

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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: April 2026.