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When to Plant Thai Basil in Lincoln 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.

Lincoln County, Minnesota is in USDA Zone 4a. The average last spring frost is May 4 and the first fall frost is October 2, giving you a growing season of approximately 151 days.

At an elevation of 1,092 feet, Lincoln County receives approximately 41.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82ยฐF, so choose short-season varieties of Thai Basil to ensure they mature before fall.

Lincoln County, MN (Zone 4a) Moderate season
151 days
Last Spring Frost May 4
151 growing days
First Fall Frost October 2

Lincoln County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-7.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (8 days to spare)
Start indoors: Mar 3 Transplant: May 19 🍅 Harvest: Jul 14 – Sep 15
Recommended (50%) ✓ Fits season (11 days to spare)
Start indoors: Mar 9 Transplant: May 25 🍅 Harvest: Jul 20 – Sep 21
Safe Start (90%) ✓ Fits season (11 days to spare)
Start indoors: Mar 20 Transplant: Jun 5 🍅 Harvest: Jul 31 – Oct 2

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 Lincoln County

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

Soil pH

Your soil pH (5.7โ€“7.2) overlaps with Thai Basil's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

The silt loam soil in Lincoln County is excellent for Thai Basil โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (5.1%) โ€” Thai Basil will thrive.

How to Plant Thai Basil

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

Succession Planting Thai Basil

3
successive plantings in your 151-day season

Sow every 5.7 weeks. Last sowing by Jul 19 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
1.2″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

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€” 1.5" 0" โ„๏ธ Dormant
Feb โ€” 2.1" 0" โ„๏ธ Dormant
Mar โ€” 2.7" 0" โ„๏ธ Dormant
Apr โ€” 4.1" 0" โ„๏ธ Dormant
May 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Jun 4.3" 6" 0" โœ… Rainfall sufficient
Jul 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Aug 4.3" 4.2" 0.1" ๐Ÿ’ง Light watering
Sep 4.3" 3.6" 0.7" ๐Ÿ’ง Light watering
Oct 4.3" 3.4" 0.9" ๐Ÿ’ง Light watering
Nov โ€” 3.2" 0" โ„๏ธ Dormant
Dec โ€” 2.6" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Mayโ€“Oct in Lincoln County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~719 GDD — county provides 1,736 GDD Excellent fit

Thai Basil Planting Timeline โ€” Lincoln 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

1"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

50โ€“75 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: acceptable

๐Ÿ—บ๏ธ USDA Zone

Zone 4a

๐Ÿ“† Growing Season

151 days in Lincoln County

Growing Tips for Thai Basil in Lincoln County

Direct sow Thai Basil outdoors after May 04 in Lincoln County when soil has warmed and frost danger has passed.

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 Lincoln County, MN?

Lincoln 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 Lincoln County, MN?

Lincoln County, Minnesota is in USDA Hardiness Zone 4a. The average last spring frost is May 4 and first fall frost is October 2.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Lincoln County gardeners in Zone 4a organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

Free download. Plan your entire garden season in minutes.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Lincoln County, MN. Local conditions may vary. Last updated: April 2026.