Blog

When to plant Basil in Madison County, MT

Plant Basil in Madison County, between June 18 and July 9 — the only viable window. Zone 5a's short season (94 frost-free days) rules out a fall crop.

When to Plant Basil in Madison County, MT

Basil

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.

Madison County, Montana is in USDA Zone 5a. The average last spring frost is June 11 and the first fall frost is September 13, giving you a growing season of approximately 94 days.

At an elevation of 6,394 feet, Madison County receives approximately 20.7 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Basil to ensure they mature before fall.

Madison County, MT (Zone 5a) Very short season
94 days
Last Spring Frost June 11
94 growing days
First Fall Frost September 13

Madison County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Basil Planting Timeline — Madison County, MT

Basil Planting Calendar

Activity When Date Range
Start Indoors April 23 Apr 23 – May 7
Transplant Outdoors June 25 Jun 25 – Jul 9
Direct Sow June 18 Jun 18 – Jul 9
Harvest August 20 Aug 20 – Oct 22

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 5a

📆 Growing Season

94 days in Madison County

Growing Tips for Madison County

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 Madison County, MT?

Madison County is in Zone 5a with an average last frost of June 11. Plan your Basil planting based on this frost date — see the calendar above for exact timing.

What planting zone is Madison County, MT?

Madison County, Montana is in USDA Hardiness Zone 5a. The average last spring frost is June 11 and first fall frost is September 13.

When should I plant Basil in Madison County, MT?

In Madison County, MT, plant Basil after the last frost (around June 11) and before the first frost (around September 13). Best results when soil holds above 50°F.

What growing zone is Madison County, MT for Basil?

Madison County sits in USDA Zone 5a. Basil grows reliably in zones 4a through 11b, so it's a good fit here.

Can Basil grow in Madison County's climate?

Yes — Basil grows well in Madison County's temperate climate. Madison County averages a 94-day frost-free season, with last frost around June 11 and first frost around September 13.

🌱

Your Madison County Garden Planner — Free

A 22-page printable planner built for Madison County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

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

Sources & credits

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