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When to Plant Mint in Oneida County, ID

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

Oneida County, Idaho is in USDA Zone 5a. The average last spring frost is May 23 and the first fall frost is September 20, giving you a growing season of approximately 120 days.

At an elevation of 8,042 feet, Oneida County receives approximately 18.4 inches of rainfall annually with predominantly loam soil. Summer highs average 85ยฐF, 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.

Oneida County, ID (Zone 5a) Short season
120 days
Last Spring Frost May 23
120 growing days
First Fall Frost September 20

Oneida County Soil Profile

Soil Type

Loam

Soil pH

6.3-8.2

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 19 🍅 Harvest: Jul 21 – Sep 29
Recommended (50%) ✗ May not fit
Transplant: May 30 🍅 Harvest: Aug 1 – Oct 10
Safe Start (90%) ✗ May not fit
Transplant: Jun 22 🍅 Harvest: Aug 24 – Nov 2

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.

Plant Water Budget

Plant needs
1.5″/week
Rainfall provides
0.6″/week
You supply
1.6″/week
Watering frequency 2-3 times/week
Season total 1,674 gal / 100 sq ft
Drought risk

Water stress score is 8/10 โ€” consider drought-tolerant varieties and mulching

Mint needs ~1,031 GDD — county provides 1,650 GDD Excellent fit

Mint Planting Timeline โ€” Oneida County, ID

Mint Planting Calendar

Activity When Date Range
Transplant Outdoors May 30 May 30 โ€“ Jun 13
Harvest August 1 Aug 1 โ€“ Oct 10

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

Month-by-Month Timeline

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

Growing Conditions

Sun

Partial Shade (3-6 hours)

Water

High โ€” keep soil consistently moist

Days to Maturity

60โ€“90 days

Soil pH

6 โ€“ 7

USDA Zone

Zone 5a

Growing Season

120 days

Growing Tips for Oneida 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

Level Up Your Garden

Frequently Asked Questions

When should I plant Mint in Oneida County, ID?

Oneida County is in Zone 5a with an average last frost of May 23. Plan your Mint planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Oneida County, ID?

Oneida County, Idaho is in USDA Hardiness Zone 5a. The average last spring frost is May 23 and first fall frost is September 20.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Oneida County gardeners in Zone 5a organize planting dates, track what's growing, and never miss a planting window.

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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 Oneida County, ID. Local conditions may vary. Last updated: April 2026.