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When to Plant Mint in Harper County, OK

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

Harper County, Oklahoma is in USDA Zone 6b. The average last spring frost is April 15 and the first fall frost is October 18, giving you a growing season of approximately 186 days.

At an elevation of 861 feet, Harper County receives approximately 21.5 inches of rainfall annually with predominantly loam soil. Summer highs average 89ยฐF, providing good warmth for Mint during the growing season.

Harper County, OK (Zone 6b) Moderate season
186 days
Last Spring Frost April 15
186 growing days
First Fall Frost October 18

Harper County Soil Profile

Soil Type

Loam

Soil pH

6.4-7.2

Drainage

Well Drained

Monthly Watering Guide for Mint

Mint needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.

Month Mint Needs Rainfall You Supplement Action
Jan โ€” 0.5" 0" โ„๏ธ Dormant
Feb โ€” 0.7" 0" โ„๏ธ Dormant
Mar โ€” 1.3" 0" โ„๏ธ Dormant
Apr 4.3" 2.2" 2.1" ๐Ÿ’ง Light watering
May 4.3" 3.2" 1.1" ๐Ÿ’ง Light watering
Jun 4.3" 3.9" 0.4" ๐Ÿ’ง Light watering
Jul 4.3" 2.9" 1.4" ๐Ÿ’ง Light watering
Aug 4.3" 2.3" 2" ๐Ÿ’ง Light watering
Sep 4.3" 2" 2.3" ๐Ÿšฟ Regular watering
Oct 4.3" 1.3" 3" ๐Ÿšฟ Regular watering
Nov โ€” 0.7" 0" โ„๏ธ Dormant
Dec โ€” 0.5" 0" โ„๏ธ Dormant

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

Mint Planting Timeline โ€” Harper County, OK

Mint Planting Calendar

Activity When Date Range
Transplant Outdoors April 22 Apr 22 โ€“ May 6
Harvest June 24 Jun 24 โ€“ Sep 2

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

Month-by-Month Timeline

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

Growing Conditions

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

High โ€” keep soil consistently moist

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: N/A

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

186 days in Harper County

Growing Tips for Harper 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 Harper County, OK?

Harper County is in Zone 6b with an average last frost of April 15. Plan your Mint planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Harper County, OK?

Harper County, Oklahoma is in USDA Hardiness Zone 6b. The average last spring frost is April 15 and first fall frost is October 18.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Harper County gardeners in Zone 6b 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 Harper County, OK. Local conditions may vary. Last updated: April 2026.