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When to Plant Mint in Adams County, WA

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

Adams County, Washington is in USDA Zone 6b. The average last spring frost is May 7 and the first fall frost is October 3, giving you a growing season of approximately 149 days.

At an elevation of 2,402 feet, Adams County receives approximately 17.1 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91ยฐF, 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.

Adams County, WA (Zone 6b) Short season
149 days
Last Spring Frost May 7
149 growing days
First Fall Frost October 3

Adams County Soil Profile

Soil Type

Silt Loam

Soil pH

5.7-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (12 days to spare)
Transplant: May 4 🍅 Harvest: Jul 6 – Sep 14
Recommended (50%) ✓ Fits season (9 days to spare)
Transplant: May 14 🍅 Harvest: Jul 16 – Sep 24
Safe Start (90%) ✓ Fits season (16 days to spare)
Transplant: May 29 🍅 Harvest: Jul 31 – Oct 9

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
0.5″/week
You supply
1.2″/week
Watering frequency 2-3 times/week
Season total 1,620 gal / 100 sq ft
Drought risk

Water stress score is 6/10 โ€” consider drought-tolerant varieties and mulching

Mint needs ~1,369 GDD — county provides 2,719 GDD Excellent fit

Mint Planting Timeline โ€” Adams County, WA

Mint Planting Calendar

Activity When Date Range
Transplant Outdoors May 14 May 14 โ€“ May 28
Harvest July 16 Jul 16 โ€“ Sep 24

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 โ€”
July Harvest
August Harvest
September Harvest
October โ€”
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 6b

Growing Season

149 days

Growing Tips for Adams 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 Adams County, WA?

Adams County is in Zone 6b with an average last frost of May 7. Plan your Mint planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Adams County, WA?

Adams County, Washington is in USDA Hardiness Zone 6b. The average last spring frost is May 7 and first fall frost is October 3.

๐ŸŒฑ

Plan Your Garden with Confidence

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