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When to Plant Mint in Suffolk County, MA

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

Suffolk County, Massachusetts is in USDA Zone 6b. The average last spring frost is April 24 and the first fall frost is October 17, giving you a growing season of approximately 176 days.

At an elevation of 984 feet, Suffolk County receives approximately 45.3 inches of rainfall annually with predominantly silt loam soil. Summer highs average 89ยฐF, providing good warmth for Mint during the growing season.

Suffolk County, MA (Zone 6b) Moderate season
176 days
Last Spring Frost April 24
176 growing days
First Fall Frost October 17

Suffolk County Soil Profile

Soil Type

Silt Loam

Soil pH

4.8-6.3

Drainage

Well Drained

Plant Planting Risk Windows

Early Start (70% safe) ✓ Fits season (34 days to spare)
Transplant: Apr 27 🍅 Harvest: Jun 29 – Sep 7
Recommended (50%) ✓ Fits season (36 days to spare)
Transplant: May 1 🍅 Harvest: Jul 3 – Sep 11
Safe Start (90%) ✓ Fits season (32 days to spare)
Transplant: May 20 🍅 Harvest: Jul 22 – Sep 30

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 Suffolk County

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

Soil pH

Your soil pH (4.8โ€“6.3) is more acidic than Mint prefers (6.0โ€“7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Suffolk County is excellent for Mint โ€” good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.6%). 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 176-day season

Sow every 6.9 weeks. Last sowing by Jul 19 to harvest before frost.

Plant Water Budget

Plant needs
0.7″/week
Rainfall provides
1.1″/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 โ€” 3" 0" โ„๏ธ Dormant
Feb โ€” 2.9" 0" โ„๏ธ Dormant
Mar โ€” 3.7" 0" โ„๏ธ Dormant
Apr 3" 3.9" 0" โœ… Rainfall sufficient
May 3" 3.8" 0" โœ… Rainfall sufficient
Jun 3" 4.1" 0" โœ… Rainfall sufficient
Jul 3" 4.8" 0" โœ… Rainfall sufficient
Aug 3" 4.2" 0" โœ… Rainfall sufficient
Sep 3" 4.1" 0" โœ… Rainfall sufficient
Oct 3" 4" 0" โœ… Rainfall sufficient
Nov โ€” 3.7" 0" โ„๏ธ Dormant
Dec โ€” 3.2" 0" โ„๏ธ Dormant

Water needs are for active growing months only (Aprโ€“Oct in Suffolk County). Supplement amounts are based on average rainfall โ€” 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" โ€” every day above 50ยฐF 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 ~1,256 GDD — county provides 2,948 GDD Excellent fit

Mint Planting Timeline โ€” Suffolk County, MA

Mint Planting Calendar

Activity When Date Range
Transplant Outdoors May 1 May 1 โ€“ May 15
Harvest July 3 Jul 3 โ€“ Sep 11

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

โ˜€๏ธ Sun

Partial Shade (3-6 hours)

๐Ÿ’ง Water

0.7"/week ยท Natural rainfall sufficient

๐Ÿ“… Days to Maturity

60โ€“90 days

๐Ÿงช Soil pH

Needs 6โ€“7 ยท Your soil: too_acidic

๐Ÿ—บ๏ธ USDA Zone

Zone 6b

๐Ÿ“† Growing Season

176 days in Suffolk County

Growing Tips for Mint in Suffolk County

Direct sow Mint outdoors after April 24 in Suffolk 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 Suffolk County, MA?

Suffolk County is in Zone 6b with an average last frost of April 24. Plan your Mint planting based on this frost date โ€” see the calendar above for exact timing.

What planting zone is Suffolk County, MA?

Suffolk County, Massachusetts is in USDA Hardiness Zone 6b. The average last spring frost is April 24 and first fall frost is October 17.

๐ŸŒฑ

Plan Your Garden with Confidence

Get our free Garden Planner โ€” designed to help Suffolk County gardeners in Zone 6b organize planting dates, track what's growing, and never miss a planting window.

Get Your Free Garden Planner →

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 Suffolk County, MA. Local conditions may vary. Last updated: April 2026.