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When to Plant Mint in Oxford County, ME

Oxford County, Maine Zone 5a May

Top priorities for Oxford County, Maine gardeners in May

May rewards gardeners who work with the weather, not against it. Here's how to stay in step this month in Oxford County, Maine.

Avg. last frost May 16
Avg. first frost September 29
Soil temp (4") 56°F
Watering Low
Pest pressure Low
Daylight 14.6 hrs
  1. Move mint from tray to bed

    Water the tray well an hour before you transplant. Roots slide out cleanly and settle in faster.

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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.

Oxford County, Maine is in USDA Zone 5a. The average last spring frost is May 16 and the first fall frost is September 29, giving you a growing season of approximately 136 days.

At an elevation of 186 feet, Oxford County receives approximately 39.9 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82°F, so choose short-season varieties of Mint to ensure they mature before fall.

Oxford County, ME (Zone 5a) Short season
136 days
Last Spring Frost May 16
136 growing days
First Fall Frost September 29

Oxford County Soil Profile

Soil Type

Silt Loam

Soil pH

4.9-6.4

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✗ May not fit
Transplant: May 18 🍅 Harvest: Jul 20 – Sep 28
Recommended (50%) ✗ May not fit
Transplant: May 23 🍅 Harvest: Jul 25 – Oct 3
Safe Start (90%) ✗ May not fit
Transplant: Jun 6 🍅 Harvest: Aug 8 – Oct 17

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 Oxford County

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

Soil pH

Your soil pH (4.9–6.4) is more acidic than Mint prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

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

Drainage

Drainage is adequate for Mint.

Organic Matter

Organic matter is moderate (3.8%). 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 136-day season

Sow every 6.9 weeks. Last sowing by Jul 01 to harvest before frost.

Plant Water Budget

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

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 2.7" 0" ❄️ Dormant
Feb 2.8" 0" ❄️ Dormant
Mar 3.5" 0" ❄️ Dormant
Apr 3.7" 0" ❄️ Dormant
May 3" 3.8" 0" ✅ Rainfall sufficient
Jun 3" 3.6" 0" ✅ Rainfall sufficient
Jul 3" 3.7" 0" ✅ Rainfall sufficient
Aug 3" 3.6" 0" ✅ Rainfall sufficient
Sep 3" 3.3" 0" ✅ Rainfall sufficient
Oct 2.8" 0" ❄️ Dormant
Nov 3.4" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

Water needs are for active growing months only (May–Sep in Oxford 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 ~862 GDD — county provides 1,564 GDD Excellent fit

Mint Planting Timeline — Oxford County, ME

Mint Planting Calendar

Activity When Date Range
Transplant Outdoors May 23 May 23 – Jun 6
Harvest July 25 Jul 25 – Oct 3

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_acidic

🗺️ USDA Zone

Zone 5a

📆 Growing Season

136 days in Oxford County

Growing Tips for Mint in Oxford County

Direct sow Mint outdoors after May 16 in Oxford 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 Oxford County, ME?

Oxford County is in Zone 5a with an average last frost of May 16. Plan your Mint planting based on this frost date — see the calendar above for exact timing.

What planting zone is Oxford County, ME?

Oxford County, Maine is in USDA Hardiness Zone 5a. The average last spring frost is May 16 and first fall frost is September 29.

🌱

Your Oxford County Garden Planner — Free

A 24-page printable planner built for Oxford County (Zone 5a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

Instant PDF download. No spam, unsubscribe any time.

Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Oxford County, ME. Local conditions may vary. Last updated: May 2026.

Sources & credits

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