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When to Plant Basil in Meagher County, MT

Meagher County, Montana Zone 4b May

This month in Meagher County, Montana

A quick May briefing for Meagher County, Montana gardeners — what's urgent, what's next, and what can wait.

Avg. last frost June 10
Avg. first frost September 8
Soil temp (4") 42°F
Watering High
Pest pressure Low
Daylight 14.8 hrs
Get ahead of June
  • Direct-sowing: basil

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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.

Meagher County, Montana is in USDA Zone 4b. The average last spring frost is June 10 and the first fall frost is September 8, giving you a growing season of approximately 90 days.

At an elevation of 5,072 feet, Meagher County receives approximately 14.2 inches of rainfall annually with predominantly loam soil. Summer highs average 83°F, so choose short-season varieties of Basil to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Basil successfully. Mulch heavily to conserve soil moisture.

Meagher County, MT (Zone 4b) Very short season
90 days
Last Spring Frost June 10
90 growing days
First Fall Frost September 8

Meagher County Soil Profile

Soil Type

Loam

Soil pH

6.5-8

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Start indoors: Apr 2 Transplant: Jun 18 🍅 Harvest: Aug 13 – Oct 15
Recommended (50%) ✗ May not fit
Start indoors: Apr 15 Transplant: Jul 1 🍅 Harvest: Aug 26 – Oct 28
Safe Start (90%) ✗ May not fit
Start indoors: Apr 29 Transplant: Jul 15 🍅 Harvest: Sep 9 – Nov 11

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 Meagher County

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

Soil pH

Your soil pH (6.5–8.0) is more alkaline than Basil prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.7%). Annual compost additions will help Basil.

How to Plant Basil

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

Succession Planting Basil

2
successive plantings in your 90-day season

Sow every 5.7 weeks. Last sowing by Jun 25 to harvest before frost.

Plant Water Budget

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

Water stress score is 8/10 — 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 1" 0" ❄️ Dormant
Feb 0.8" 0" ❄️ Dormant
Mar 1.4" 0" ❄️ Dormant
Apr 1.4" 0" ❄️ Dormant
May 1.9" 0" ❄️ Dormant
Jun 2.6" 0.9" 1.7" 🚿 Regular watering
Jul 2.6" 1.1" 1.5" 🚿 Regular watering
Aug 2.6" 1.5" 1.1" 💧 Light watering
Sep 2.6" 1.1" 1.5" 🚿 Regular watering
Oct 1.3" 0" ❄️ Dormant
Nov 1" 0" ❄️ Dormant
Dec 0.9" 0" ❄️ Dormant

Water needs are for active growing months only (Jun–Sep in Meagher County). Supplement amounts are based on average rainfall — 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" — 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.

Basil needs ~766 GDD — county provides 1,102 GDD Excellent fit

Basil Planting Timeline — Meagher County, MT

Basil Planting Calendar

Activity When Date Range
Start Indoors April 15 Apr 15 – Apr 29
Transplant Outdoors July 1 Jul 1 – Jul 15
Direct Sow June 17 Jun 17 – Jul 8
Harvest August 26 Aug 26 – Oct 28

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.6"/week · Natural rainfall sufficient

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 4b

📆 Growing Season

90 days in Meagher County

Growing Tips for Basil in Meagher County

Direct sow Basil outdoors after June 10 in Meagher 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 →

🌾 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 35°F, under 45% humidity.

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

Frequently Asked Questions

When should I plant Basil in Meagher County, MT?

Meagher County is in Zone 4b with an average last frost of June 10. Plan your Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Meagher County, MT?

Meagher County, Montana is in USDA Hardiness Zone 4b. The average last spring frost is June 10 and first fall frost is September 8.

🌱

Your Meagher County Garden Planner — Free

A 24-page printable planner built for Meagher County (Zone 4b). 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 Meagher County, MT. 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.