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When to plant Mint in Broomfield County, CO

Plant Mint in Broomfield County during the brief May 21–June 4 window. With 135 frost-free days, fall plantings can't mature before September 26.

When to Plant Mint in Broomfield County, CO

Mint

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

Broomfield County, Colorado is in USDA Zone 6a. The average last spring frost is May 14 and the first fall frost is September 26, giving you a growing season of approximately 135 days.

At an elevation of 7,037 feet, Broomfield County receives approximately 13.9 inches of rainfall annually with predominantly loam soil. Summer highs average 87°F, providing good warmth for Mint during the growing season. With low rainfall, drip irrigation is essential for growing Mint successfully. Mulch heavily to conserve soil moisture.

Broomfield County, CO (Zone 6a) Short season
135 days
Last Spring Frost May 14
135 growing days
First Fall Frost September 26

Broomfield County Soil Profile

Soil Type

Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Mint Planting Timeline — Broomfield County, CO

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 6a

📆 Growing Season

135 days in Broomfield County

Growing Tips for Broomfield 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 Broomfield County, CO?

Broomfield County is in Zone 6a 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 Broomfield County, CO?

Broomfield County, Colorado is in USDA Hardiness Zone 6a. The average last spring frost is May 14 and first fall frost is September 26.

When should I plant Mint in Broomfield County, CO?

In Broomfield County, CO, plant Mint after the last frost (around May 14) and before the first frost (around September 26). Best results when soil holds above 50°F.

What growing zone is Broomfield County, CO for Mint?

Broomfield County sits in USDA Zone 6a. Mint grows reliably in zones 3a through 10b, so it's a good fit here.

Can Mint grow in Broomfield County's climate?

Yes — Mint grows well in Broomfield County's temperate climate. Broomfield County averages a 135-day frost-free season, with last frost around May 14 and first frost around September 26.

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Your Broomfield County Garden Planner — Free

A 22-page printable planner built for Broomfield County (Zone 6a). 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 Broomfield County, CO. Local conditions may vary. Last updated: July 2026.

Sources & credits

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