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When to Plant Mint in Kootenai County, ID

Kootenai County, Idaho Zone 6a April

Top priorities for Kootenai County, Idaho gardeners in April

If you only do a handful of things in the garden this April, make it these. They're sequenced around your zone's frost timing.

Avg. last frost April 29
Avg. first frost October 8
Soil temp (4") 35°F
Watering High
Pest pressure Low
Daylight 13.4 hrs
To set up a strong May, finish these tasks
  • Transplants going out: mint

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

Kootenai County, Idaho is in USDA Zone 6a. The average last spring frost is April 29 and the first fall frost is October 8, giving you a growing season of approximately 162 days.

At an elevation of 5,986 feet, Kootenai County receives approximately 20.7 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Mint during the growing season.

Kootenai County, ID (Zone 6a) Moderate season
162 days
Last Spring Frost April 29
162 growing days
First Fall Frost October 8

Kootenai County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.7

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (23 days to spare)
Transplant: Apr 29 🍅 Harvest: Jul 1 – Sep 9
Recommended (50%) ✓ Fits season (22 days to spare)
Transplant: May 6 🍅 Harvest: Jul 8 – Sep 16
Safe Start (90%) ✓ Fits season (25 days to spare)
Transplant: May 24 🍅 Harvest: Jul 26 – Oct 4

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 Kootenai County

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

Soil pH

Your soil pH (6.7–7.7) is more alkaline than Mint prefers (6.0–7.0). Add sulfur or peat moss to lower pH.

Soil Texture

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

Organic Matter

Organic matter is moderate (2.3%). Annual compost additions will help Mint.

How to Plant Mint

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

Succession Planting Mint

3
successive plantings in your 162-day season

Sow every 6.9 weeks. Last sowing by Jul 10 to harvest before frost.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
0.5″/week
You supply
0.2″/week
Watering frequency Only during dry spells
Season total 283 gal / 100 sq ft
Drought risk

Water stress score is 6/10 — consider drought-tolerant varieties and mulching

Monthly Watering Guide for Mint

Mint needs approximately 0.7 inches of water per week (3" per month). Here's how your county's rainfall compares month by month.

Month Mint Needs Rainfall You Supplement Action
Jan 1.5" 0" ❄️ Dormant
Feb 1.2" 0" ❄️ Dormant
Mar 1.7" 0" ❄️ Dormant
Apr 3" 2.4" 0.6" 💧 Light watering
May 3" 2.7" 0.3" 💧 Light watering
Jun 3" 1.3" 1.7" 🚿 Regular watering
Jul 3" 1.9" 1.1" 💧 Light watering
Aug 3" 2" 1" 💧 Light watering
Sep 3" 1.9" 1.1" 💧 Light watering
Oct 3" 1.5" 1.5" 🚿 Regular watering
Nov 1.3" 0" ❄️ Dormant
Dec 1.3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Kootenai County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Mint 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.

Mint needs ~1,088 GDD — county provides 2,349 GDD Excellent fit

Mint Planting Timeline — Kootenai County, ID

Mint Planting Calendar

Activity When Date Range
Transplant Outdoors May 6 May 6 – May 20
Harvest July 8 Jul 8 – Sep 16

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

Month-by-Month Timeline

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

Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

0.7"/week · Only during dry spells

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 6a

📆 Growing Season

162 days in Kootenai County

Growing Tips for Mint in Kootenai County

Direct sow Mint outdoors after April 29 in Kootenai County when soil has warmed and frost danger has passed.

General growing tips

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 Kootenai County, ID?

Kootenai County is in Zone 6a with an average last frost of April 29. Plan your Mint planting based on this frost date — see the calendar above for exact timing.

What planting zone is Kootenai County, ID?

Kootenai County, Idaho is in USDA Hardiness Zone 6a. The average last spring frost is April 29 and first fall frost is October 8.

🌱

Your Kootenai County Garden Planner — Free

A 24-page printable planner built for Kootenai 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 Kootenai County, ID. Local conditions may vary. Last updated: April 2026.

Sources & credits

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