Suffolk County, in Massachusetts, sits in USDA hardiness zone 7a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Reliable performers under these conditions include tomato, blueberry, sugar maple, and zucchini; what your own ground favors still comes down to its soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
You’re in Greater Boston
The state's dense urban core, where growing means raised beds, community plots, and back-lot kitchen gardens more than open field. A long, mild season for the region — but city soil is the thing to know before you dig.
Suffolk County holds more than one microclimate.
Soils and elevations shift across Suffolk County, so your frost dates and drainage aren't the county average. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Quick Facts
USDA Zones
7a
Last Hard Freeze (28°F)
Mar 27
County normal — light frosts run a few weeks later
First Hard Freeze (28°F)
Nov 29
County normal — light frosts arrive a few weeks earlier
County Area
37K acres
Hardiness Zone Range
Zone maps are averages across Suffolk County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil in Suffolk County
Across Suffolk County, the ground is predominantly Inceptisols, where Canton, Merrimac, and Woodbridge are the most extensive named soil series. The soil is generally well drained with a fine sandy loam surface. Topsoil pH runs about 4.6–5.3, very strongly acidic. Rainfall drains through hydrologic group A soils.
Soil order
Inceptisols
Drainage
Well drained
Prime farmland
15%
Hydric soils
20%
Soil still varies lot by lot — soil types explained.
What Grows in Suffolk County
Plants matched to Suffolk County's USDA zones 7a — each links to its full growing profile.
Is it too late to plant in Suffolk County?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Feb 27; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 29 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
Growing Challenges in Massachusetts
What an experienced grower plans around here — each one has a move.
Short growing season (120-180 frost-free days) limits warm-season crops
Pick fast-maturing varieties and start warm-season crops indoors — a cold frame or low tunnel reliably adds weeks on either end.
Rocky glacial soils require amendment in many areas
A raised bed with imported soil skips the rock-picking entirely and starts your first season on your terms.
Late spring frosts can damage early plantings through mid-May
Trust your local last-frost window over the calendar — hardy greens can go out weeks early while tender transplants wait it out.
Deer pressure is significant in suburban and rural areas
An 8-foot fence — or a slanted double line — is the fix that actually holds; lean the unfenced edges toward deer-resistant herbs, ferns, and bulbs.
For cultivar selection, pest pressure, and planting-time guidance specific to Massachusetts, the UMass Extension is the authoritative local source.
Safe to Grow Here?
What the federal record shows across Suffolk County — and how to grow with it.
We checked the federal record across Suffolk County — 2,900 documented sites across 7 of the 9 source types we track.
The most significant on record: 21 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Suffolk County carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
Environmental Intelligence
Understanding what's nearby helps you make informed decisions about where and how to grow.
Sources Checked
across Suffolk County
Severity Distribution
across Suffolk County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Suffolk County, Brownfields runs higher than the national average — 2,053 sites nearby. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Check your specific parcel in Suffolk County
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Your Specific Parcel Matters
Suffolk County Average
- ●USDA Zones 7a
- ●Generic soil type for the area
- ●State-average frost dates
YOUR Parcel
- ✓Your exact hardiness zone
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Suffolk County
Pull a site-specific report for your exact address in Suffolk County, Massachusetts — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Key Growing Facts for Suffolk County, Massachusetts
- USDA Hardiness Zones: 7a (USDA PHZM 2023)
- Last Hard Freeze (28°F): Mar 27 (county normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
- First Hard Freeze (28°F): Nov 29 (county normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
- Days Between Hard Freezes: ~247 (county normal, NOAA 1991–2020 Climate Normals)
- County Land Area: 37K acres (US Census TIGER 2025)
Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. County boundaries: US Census TIGER/Line 2025.
Frost dates here are the Suffolk County average. Low spots and tree cover move them by days on any one yard — see your exact frost windows.
Frequently Asked Questions
What hardiness zone is Suffolk County, Massachusetts?
Suffolk County sits in USDA hardiness zone 7a, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
Is it too late to plant in Suffolk County?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Feb 27; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 29 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
When does frost risk typically end in Suffolk County?
The last hard freeze (28°F) in Suffolk County typically lands around Mar 27, per NOAA 1991–2020 climate normals — an earlier marker than the light-frost dates many planting charts quote. That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.
How long is the growing season in Suffolk County?
Measured between 28°F hard freezes, Suffolk County sees about 247 frost-free days — roughly Mar 27 through Nov 29, per NOAA 1991–2020 climate normals. Tender crops get a somewhat shorter practical window, since lighter frosts reach a few weeks past the hard-freeze dates on both ends.
What vegetables grow in Suffolk County?
Suffolk County's zone 7a supports a wide range — strong performers include Tomato, Blueberry, Sugar Maple, Zucchini, and Kale. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.
Which hardiness zone is Suffolk County, really?
Officially, Suffolk County sits in USDA zone 7a (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.
Is the soil safe to grow vegetables in Suffolk County?
The federal record around Suffolk County runs heavier than most — 2,900 documented sites — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
Just moved to Suffolk County — what should I know before planting?
Start with three facts. Suffolk County sits in USDA zone 7a, which sets what survives winter; the last 28°F hard freeze typically clears around Mar 27, with about 247 frost-free days to work with (NOAA 1991–2020 climate normals); and 2,900 documented sites sit on the federal record here, so a soil test before food beds is the smart first step. From there, matching plants to your actual soil and sun is the fun part.
Everything on this page is a Suffolk County average. Your yard writes its own version — we read soil, sun, drainage, and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Massachusetts's frost window, season length, and soil profile against the plant's real requirements.