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When to Plant Basil in Morton County, ND

Basil is a fragrant warm-season herb essential to Italian and Thai cuisines. It comes in many varieties including sweet, Thai, purple, and lemon types.

Morton County, North Dakota is in USDA Zone 4a. The average last spring frost is May 14 and the first fall frost is September 23, giving you a growing season of approximately 132 days.

At an elevation of 752 feet, Morton County receives approximately 33 inches of rainfall annually with predominantly loam soil. Summer highs average 80ยฐF, so choose short-season varieties of Basil to ensure they mature before fall.

Morton County, ND (Zone 4a) Short season
132 days
Last Spring Frost May 14
132 growing days
First Fall Frost September 23

Morton County Soil Profile

Soil Type

Loam

Soil pH

6.3-7.6

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Mar 15 Transplant: May 31 🍅 Harvest: Jul 26 – Sep 27
Recommended (50%) ✗ May not fit
Start indoors: Mar 19 Transplant: Jun 4 🍅 Harvest: Jul 30 – Oct 1
Safe Start (90%) ✗ May not fit
Start indoors: Apr 8 Transplant: Jun 24 🍅 Harvest: Aug 19 – Oct 21

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 Morton County

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

Soil pH

Your soil pH (6.3โ€“7.6) overlaps with Basil's range (6.0โ€“7.0), though not a perfect match.

Soil Texture

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

Organic Matter

Organic matter is excellent (4.1%) โ€” Basil will thrive.

How to Plant Basil

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

Succession Planting Basil

3
successive plantings in your 132-day season

Sow every 5.7 weeks. Last sowing by Jul 10 to harvest before frost.

Plant Water Budget

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

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Monthly Watering Guide for Basil

Basil needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.

Month Basil Needs Rainfall You Supplement Action
Jan โ€” 2.2" 0" โ„๏ธ Dormant
Feb โ€” 1.8" 0" โ„๏ธ Dormant
Mar โ€” 2.6" 0" โ„๏ธ Dormant
Apr โ€” 3.6" 0" โ„๏ธ Dormant
May 2.6" 4.1" 0" โœ… Rainfall sufficient
Jun 2.6" 2.2" 0.4" ๐Ÿ’ง Light watering
Jul 2.6" 2.8" 0" โœ… Rainfall sufficient
Aug 2.6" 4" 0" โœ… Rainfall sufficient
Sep 2.6" 2.9" 0" โœ… Rainfall sufficient
Oct โ€” 2.7" 0" โ„๏ธ Dormant
Nov โ€” 2.4" 0" โ„๏ธ Dormant
Dec โ€” 1.8" 0" โ„๏ธ Dormant

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

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.

Basil needs ~625 GDD — county provides 1,320 GDD Excellent fit

Basil Planting Timeline โ€” Morton County, ND

Basil Planting Calendar

Activity When Date Range
Start Indoors March 19 Mar 19 โ€“ Apr 2
Transplant Outdoors June 4 Jun 4 โ€“ Jun 18
Direct Sow May 21 May 21 โ€“ Jun 11
Harvest July 30 Jul 30 โ€“ Oct 1

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Full Sun (6-8+ hours)

๐Ÿ’ง Water

0.6"/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

132 days in Morton County

Growing Tips for Basil in Morton County

Direct sow Basil outdoors after May 14 in Morton County when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors or direct sow after last frost. Pinch flower buds to extend leaf production. Harvest leaves from the top down, cutting just above a leaf pair.

Companion Planting

Good Companions

Avoid Planting Near

  • Rue
  • Sage

Check more plant combinations with our Companion Planting Checker →

๐ŸŒพ Save Your Own Basil Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let flower spikes dry brown on the plant.
Storage Store airtight; viable 5 years at 35ยฐF, under 45% humidity.

Isolate 150 ft between varieties. Different basil species can cross.

Frequently Asked Questions

When should I plant Basil in Morton County, ND?

Morton County is in Zone 4a with an average last frost of May 14. Plan your Basil planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Morton County, ND?

Morton County, North Dakota is in USDA Hardiness Zone 4a. The average last spring frost is May 14 and first fall frost is September 23.

๐ŸŒฑ

Plan Your Garden with Confidence

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