Suffolk County, in New York, 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 apple, grape, garlic, and kale; 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
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 25
County normal — light frosts run a few weeks later
First Hard Freeze (28°F)
Dec 2
County normal — light frosts arrive a few weeks earlier
County Area
583K 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 Riverhead, Plymouth, and Haven are the most extensive named soil series. The soil is generally well drained with a sandy loam surface. Topsoil pH runs about 4.4–5.3, very strongly acidic. Rainfall drains through hydrologic group A soils.
Soil order
Inceptisols
Drainage
Well drained
Prime farmland
29%
Hydric soils
6%
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 25; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 25 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 2 — 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 New York
What an experienced grower plans around here — each one has a move.
Short upstate growing season (100-140 frost-free days in Adirondacks)
Fast varieties plus season extension: a low tunnel or cold frame reliably buys back the missing weeks.
Heavy clay soils in western NY require drainage improvement
A raised bed solves the drainage the first season; long-term, steady compost works that clay into excellent loam.
Late spring frosts through May in higher elevations
Plant to your elevation's real frost dates, not the valley's — two weeks of patience saves a full replanting.
Deer browse pressure is heavy in suburban and rural areas
Fencing is the control that works; behind it, aromatic herbs, ferns, and daffodils are the plants deer tend to pass by.
For cultivar selection, pest pressure, and planting-time guidance specific to New York, the Cornell Cooperative 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 — 6,351 documented sites across 6 of the 9 source types we track.
The most significant on record: 65 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, Nitrate runs higher than the national average — 3,314 sites nearby. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
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, New York — 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, New York
- USDA Hardiness Zones: 7a (USDA PHZM 2023)
- Last Hard Freeze (28°F): Mar 25 (county normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
- First Hard Freeze (28°F): Dec 2 (county normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
- Days Between Hard Freezes: ~252 (county normal, NOAA 1991–2020 Climate Normals)
- County Land Area: 583K 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, New York?
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 25; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 25 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 2 — 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 25, 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 252 frost-free days — roughly Mar 25 through Dec 2, 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 Apple, Grape, Garlic, Kale, and Sugar Maple. 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 — 6,351 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 25, with about 252 frost-free days to work with (NOAA 1991–2020 climate normals); and 6,351 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 New York's frost window, season length, and soil profile against the plant's real requirements.