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When to Plant Thai Basil in Pine County, MN

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.

Pine County, Minnesota is in USDA Zone 4a. The average last spring frost is May 10 and the first fall frost is September 29, giving you a growing season of approximately 142 days.

At an elevation of 538 feet, Pine County receives approximately 33.4 inches of rainfall annually with predominantly silt loam soil. Summer highs average 84ยฐF, so choose short-season varieties of Thai Basil to ensure they mature before fall.

Pine County, MN (Zone 4a) Short season
142 days
Last Spring Frost May 10
142 growing days
First Fall Frost September 29

Pine County Soil Profile

Soil Type

Silt Loam

Soil pH

6-7.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (6 days to spare)
Start indoors: Mar 5 Transplant: May 21 🍅 Harvest: Jul 16 – Sep 17
Recommended (50%) ✓ Fits season (2 days to spare)
Start indoors: Mar 15 Transplant: May 31 🍅 Harvest: Jul 26 – Sep 27
Safe Start (90%) ✓ Fits season (6 days to spare)
Start indoors: Mar 26 Transplant: Jun 11 🍅 Harvest: Aug 6 – Oct 8

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
1.0″/week
You supply
0.0″/week
Watering frequency Only during dry spells
Season total 15 gal / 100 sq ft
Thai Basil needs ~812 GDD — county provides 1,846 GDD Excellent fit

Thai Basil Planting Timeline โ€” Pine County, MN

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors March 15 Mar 15 โ€“ Mar 29
Transplant Outdoors May 31 May 31 โ€“ Jun 14
Direct Sow May 17 May 17 โ€“ Jun 7
Harvest July 26 Jul 26 โ€“ Sep 27

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

Month-by-Month Timeline

MonthActivities
January โ€”
February โ€”
March Start Indoors
April โ€”
May Transplant Outdoors Direct Sow
June Transplant Outdoors Direct Sow
July Harvest
August Harvest
September Harvest
October โ€”
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 4a

Growing Season

142 days

Growing Tips for Pine 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 Pine County, MN?

Pine County is in Zone 4a with an average last frost of May 10. Plan your Thai Basil planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Pine County, MN?

Pine County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 10 and first fall frost is September 29.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Pine County gardeners in Zone 4a 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 Pine County, MN. Local conditions may vary. Last updated: April 2026.