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When to plant Mint in Hill County, MT

Hill County's 132-day season only supports one Mint planting per year. Sow between May 21 and June 4 for the best chance at full maturity before September 23.

When to Plant Mint in Hill County, MT

Mint

Mint is a vigorous perennial herb with refreshing, aromatic leaves used in teas, cocktails, and cooking. It spreads aggressively by underground runners.

Hill County, Montana 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 5,229 feet, Hill County receives approximately 14.4 inches of rainfall annually with predominantly loam soil. Summer highs average 80°F, so choose short-season varieties of Mint to ensure they mature before fall. With low rainfall, drip irrigation is essential for growing Mint successfully. Mulch heavily to conserve soil moisture.

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

Hill County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Mint Planting Timeline — Hill County, MT

Mint Planting Calendar

Activity When Date Range
Transplant Outdoors May 21 May 21 – Jun 4
Harvest July 23 Jul 23 – Oct 1

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

High — keep soil consistently moist

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 4a

📆 Growing Season

132 days in Hill County

Growing Tips for Hill County

Always grow mint in containers or with underground barriers to control spreading. Harvest regularly to keep plants compact. Cut plants back in late summer for a fresh fall flush.

Companion Planting

Good Companions

Avoid Planting Near

  • Parsley

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Mint in Hill County, MT?

Hill County is in Zone 4a with an average last frost of May 14. Plan your Mint planting based on this frost date — see the calendar above for exact timing.

What planting zone is Hill County, MT?

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

When should I plant Mint in Hill County, MT?

In Hill County, MT, plant Mint after the last frost (around May 14) and before the first frost (around September 23). Best results when soil holds above 50°F.

What growing zone is Hill County, MT for Mint?

Hill County sits in USDA Zone 4a. Mint grows reliably in zones 3a through 10b, so it's a good fit here.

Can Mint grow in Hill County's climate?

Yes — Mint grows well in Hill County's temperate climate. Hill County averages a 132-day frost-free season, with last frost around May 14 and first frost around September 23.

🌱

Your Hill County Garden Planner — Free

A 22-page printable planner built for Hill 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 Hill County, MT. Local conditions may vary. Last updated: June 2026.

Sources & credits

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