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When to Plant Thai Basil in Morrison 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.

Morrison County, Minnesota is in USDA Zone 4a. The average last spring frost is May 4 and the first fall frost is October 6, giving you a growing season of approximately 155 days.

At an elevation of 1,070 feet, Morrison County receives approximately 40 inches of rainfall annually with predominantly silt loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Thai Basil to ensure they mature before fall.

Morrison County, MN (Zone 4a) Moderate season
155 days
Last Spring Frost May 4
155 growing days
First Fall Frost October 6

Morrison County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.1

Drainage

Well Drained

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 โ€” 1.4" 0" โ„๏ธ Dormant
Feb โ€” 1.6" 0" โ„๏ธ Dormant
Mar โ€” 2.7" 0" โ„๏ธ Dormant
Apr โ€” 3.8" 0" โ„๏ธ Dormant
May 4.3" 5" 0" โœ… Rainfall sufficient
Jun 4.3" 5.5" 0" โœ… Rainfall sufficient
Jul 4.3" 4" 0.3" ๐Ÿ’ง Light watering
Aug 4.3" 4.6" 0" โœ… Rainfall sufficient
Sep 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Oct 4.3" 3.1" 1.2" ๐Ÿ’ง Light watering
Nov โ€” 2.7" 0" โ„๏ธ Dormant
Dec โ€” 1.9" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Morrison County). Supplement amounts are based on average rainfall โ€” actual needs vary with temperature, soil, and mulching.

Thai Basil Planting Timeline โ€” Morrison County, MN

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors March 9 Mar 9 โ€“ Mar 23
Transplant Outdoors May 25 May 25 โ€“ Jun 8
Direct Sow May 11 May 11 โ€“ Jun 1
Harvest July 20 Jul 20 โ€“ Sep 21

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

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

Moderate โ€” regular watering

๐Ÿ“… Days to Maturity

50โ€“75 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

155 days in Morrison County

Growing Tips for Morrison 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 Morrison County, MN?

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

What planting zone is Morrison County, MN?

Morrison County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 4 and first fall frost is October 6.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Morrison 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 Morrison County, MN. Local conditions may vary. Last updated: April 2026.