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When to plant Thai Basil in Knox County, ME

Knox County's spring Thai Basil window runs May 9 through May 30. time plantings around the expected last-frost window for best survival.

When to Plant Thai Basil in Knox County, ME

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.

Knox County, Maine is in USDA Zone 6a. The average last spring frost is May 2 and the first fall frost is October 12, giving you a growing season of approximately 163 days.

At an elevation of 408 feet, Knox County receives approximately 41.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 83°F, so choose short-season varieties of Thai Basil to ensure they mature before fall.

Knox County, ME (Zone 6a) Moderate season
163 days
Last Spring Frost May 2
163 growing days
First Fall Frost October 12

Knox County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Thai Basil Planting Timeline — Knox County, ME

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors March 14 Mar 14 – Mar 28
Transplant Outdoors May 16 May 16 – May 30
Direct Sow May 9 May 9 – May 30
Harvest July 11 Jul 11 – Sep 12

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 6a

📆 Growing Season

163 days in Knox County

Growing Tips for Knox 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

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Thai Basil in Knox County, ME?

Knox County is in Zone 6a with an average last frost of May 2. Plan your Thai Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Knox County, ME?

Knox County, Maine is in USDA Hardiness Zone 6a. The average last spring frost is May 2 and first fall frost is October 12.

When should I plant Thai Basil in Knox County, ME?

In Knox County, ME, plant Thai Basil after the last frost (around May 2) and before the first frost (around October 12). Best results when soil holds above 50°F.

What growing zone is Knox County, ME for Thai Basil?

Knox County sits in USDA Zone 6a. Thai Basil grows reliably in zones 4a through 11b, so it's a good fit here.

Can Thai Basil grow in Knox County's climate?

Yes — Thai Basil grows well in Knox County's temperate climate. Knox County averages a 163-day frost-free season, with last frost around May 2 and first frost around October 12.

🌱

Your Knox County Garden Planner — Free

A 22-page printable planner built for Knox County (Zone 6a). 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 Knox County, ME. Local conditions may vary. Last updated: June 2026.

Sources & credits

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