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When to plant Mint in Boise County, ID

Boise County sits in cold Zone 7a. Plant Mint May 25–June 8 for the single annual harvest; the September 27 first frost closes the window.

When to Plant Mint in Boise County, ID

Mint
Boise County, Idaho Zone 7a July

July to-do list for Boise County, Idaho

Here's what deserves your attention in Boise County, Idaho this month. Everything below is tailored to Zone 7a and timed around your local frost dates.

Avg. last frost May 18
Avg. first frost September 27
Soil temp (4") 50°F
Watering High
Pest pressure High
Daylight 15 hrs
  1. Pick mint

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

A few tasks this July that'll pay off in August
  • First harvests: 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.

Boise County, Idaho is in USDA Zone 7a. The average last spring frost is May 18 and the first fall frost is September 27, giving you a growing season of approximately 132 days.

At an elevation of 8,023 feet, Boise County receives approximately 24.3 inches of rainfall annually with predominantly loam soil. Summer highs average 86°F, providing good warmth for Mint during the growing season.

Boise County, ID (Zone 7a) Short season
132 days
Last Spring Frost May 18
132 growing days
First Fall Frost September 27

Boise County Soil Profile

Soil Type

Loam

Soil pH

6.7-7.7

Drainage

Well Drained

Mint Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 12 🍅 Harvest: Jul 14 – Sep 22
Recommended (50%) ✗ May not fit
Transplant: May 25 🍅 Harvest: Jul 27 – Oct 5
Safe Start (90%) ✗ May not fit
Transplant: Jun 23 🍅 Harvest: Aug 25 – Nov 3

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 Boise 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 Boise 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

2
successive plantings in your 132-day season

Sow every 6.9 weeks. Last sowing by Jun 29 to harvest before frost.

Mint Water Budget

Plant needs
0.7″/week
Rainfall provides
0.8″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft
Drought risk

Water stress score is 8/10 — 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 1.8" 0" ❄️ Dormant
Feb 1.4" 0" ❄️ Dormant
Mar 2.1" 0" ❄️ Dormant
Apr 2.4" 0" ❄️ Dormant
May 3" 3" 0" ✅ Rainfall sufficient
Jun 3" 1.9" 1.1" 💧 Light watering
Jul 3" 1.8" 1.2" 💧 Light watering
Aug 3" 2.8" 0.2" 💧 Light watering
Sep 3" 1.7" 1.3" 💧 Light watering
Oct 2.4" 0" ❄️ Dormant
Nov 1.5" 0" ❄️ Dormant
Dec 1.5" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Boise 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 1,914 GDD Excellent fit

Mint Planting Timeline — Boise County, ID

Mint Planting Calendar

Activity When Date Range
Transplant Outdoors May 25 May 25 – Jun 8
Harvest July 27 Jul 27 – Oct 5

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

0.7"/week · Natural rainfall sufficient

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: too_alkaline

🗺️ USDA Zone

Zone 7a

📆 Growing Season

132 days in Boise County

Growing Tips for Mint in Boise County

Direct sow Mint outdoors after May 18 in Boise 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 Boise County, ID?

Boise County is in Zone 7a with an average last frost of May 18. Plan your Mint planting based on this frost date — see the calendar above for exact timing.

What planting zone is Boise County, ID?

Boise County, Idaho is in USDA Hardiness Zone 7a. The average last spring frost is May 18 and first fall frost is September 27.

When should I plant Mint in Boise County, ID?

In Boise County, ID, plant Mint after the last frost (around May 18) and before the first frost (around September 27). Best results when soil holds above 50°F.

What growing zone is Boise County, ID for Mint?

Boise County sits in USDA Zone 7a. Mint grows reliably in zones 3a through 10b, so it's a good fit here.

Can Mint grow in Boise County's climate?

Yes — Mint grows well in Boise County's temperate climate. Boise County averages a 132-day frost-free season, with last frost around May 18 and first frost around September 27.

🌱

Your Boise County Garden Planner — Free

A 22-page printable planner built for Boise County (Zone 7a). 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 Boise County, ID. 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.