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When to Plant Thai Basil in Logan County, ND

Logan County, North Dakota Zone 4a May

Your May gardening checklist

Your garden in Logan County, North Dakota is working on a schedule, even when you're not. Here's where you should be this May.

Avg. last frost May 13
Avg. first frost September 28
Soil temp (4") 54°F
Watering Low
Pest pressure Low
Daylight 14.8 hrs
  1. Put thai basil seeds straight in the ground

    Sow every 2 weeks for a continuous harvest. A single big planting means a single big glut.

A few tasks this May that'll pay off in June
  • Transplants going out: thai basil

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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.

Logan County, North Dakota is in USDA Zone 4a. The average last spring frost is May 13 and the first fall frost is September 28, giving you a growing season of approximately 138 days.

At an elevation of 1,073 feet, Logan County receives approximately 25.2 inches of rainfall annually with predominantly loam soil. Summer highs average 82°F, so choose short-season varieties of Thai Basil to ensure they mature before fall.

Logan County, ND (Zone 4a) Short season
138 days
Last Spring Frost May 13
138 growing days
First Fall Frost September 28
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Logan County Soil Profile

Soil Type

Loam

Soil pH

6.5-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 12 Transplant: May 28 🍅 Harvest: Jul 23 – Sep 24
Recommended (50%) ✗ May not fit
Start indoors: Mar 18 Transplant: Jun 3 🍅 Harvest: Jul 29 – Sep 30
Safe Start (90%) ✗ May not fit
Start indoors: Mar 31 Transplant: Jun 16 🍅 Harvest: Aug 11 – Oct 13

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 Logan County

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

Soil pH

Your soil pH (6.5–7.7) is more alkaline than Thai Basil prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

The loam soil in Logan County is excellent for Thai Basil — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is excellent (4.1%) — 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 138-day season

Sow every 5.7 weeks. Last sowing by Jul 15 to harvest before frost.

Plant Water Budget

Plant needs
1.0″/week
Rainfall provides
0.8″/week
You supply
0.3″/week
Watering frequency Only during dry spells
Season total 343 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — 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 0.6" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.5" 0" ❄️ Dormant
Apr 2.8" 0" ❄️ Dormant
May 4.3" 3.8" 0.5" 💧 Light watering
Jun 4.3" 3.9" 0.4" 💧 Light watering
Jul 4.3" 3.3" 1" 💧 Light watering
Aug 4.3" 2.9" 1.4" 💧 Light watering
Sep 4.3" 2.5" 1.8" 💧 Light watering
Oct 1.5" 0" ❄️ Dormant
Nov 0.9" 0" ❄️ Dormant
Dec 0.6" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Logan County). Supplement amounts are based on average rainfall — 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" — every day above 50°F 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 1,587 GDD Excellent fit

Thai Basil Planting Timeline — Logan County, ND

Thai Basil Planting Calendar

Activity When Date Range
Start Indoors March 18 Mar 18 – Apr 1
Transplant Outdoors June 3 Jun 3 – Jun 17
Direct Sow May 20 May 20 – Jun 10
Harvest July 29 Jul 29 – Sep 30

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

Month-by-Month Timeline

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

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

1"/week · Only during dry spells

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 4a

📆 Growing Season

138 days in Logan County

Growing Tips for Thai Basil in Logan County

Direct sow Thai Basil outdoors after May 13 in Logan 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 Logan County, ND?

Logan County is in Zone 4a with an average last frost of May 13. Plan your Thai Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Logan County, ND?

Logan County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 13 and first fall frost is September 28.

🌱

Your Logan County Garden Planner — Free

A 24-page printable planner built for Logan County (Zone 4a). 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 Logan County, ND. Local conditions may vary. Last updated: May 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.