Middlesex County, in New Jersey, 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.
The conditions favor tomato, blueberry, peach, and sweet corn, among others — though every individual site edits that list with its own soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Middlesex County holds more than one microclimate.
Soils and elevations shift across Middlesex 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 19
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
198K acres
Hardiness Zone Range
Zone maps are averages across Middlesex County. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
Soil in Middlesex County
Across Middlesex County, the ground is predominantly Ultisols, where Sassafras, Woodstown, and Boonton are the most extensive named soil series. The soil is generally well drained with a loam surface. Topsoil pH runs about 4.6–5.5, very strongly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Ultisols
Drainage
Well drained
Prime farmland
28%
Hydric soils
23%
Soil still varies lot by lot — soil types explained.
What Grows in Middlesex County
Plants matched to Middlesex County's USDA zones 7a — each links to its full growing profile.





Is it too late to plant in Middlesex County?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Feb 19; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 19 (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. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.

Growing Challenges in New Jersey
What an experienced grower plans around here — each one has a move.

Sandy Pine Barrens soils are nutrient-poor
Compost and cover crops build the Barrens' sand into real soil — organic matter, added every year, is the whole fix.

Urban heat island effects in northern NJ
The city's extra warmth stretches the season for heat-lovers — find your true effective zone and use the head start.

Deer browse is extreme in suburban areas
Fencing holds the line; outside it, aromatic and fuzzy-leaved plants are the ones deer tend to leave alone.
For cultivar selection, pest pressure, and planting-time guidance specific to New Jersey, the Rutgers Cooperative Extension is the authoritative local source.
Safe to Grow Here?
What the federal record shows across Middlesex County — and how to grow with it.
We checked the federal record across Middlesex County — 4,027 documented sites across 7 of the 9 source types we track.
The most significant on record: 101 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Middlesex 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 Middlesex County
Severity Distribution
across Middlesex County
Highest-Severity Sites

A note from Gnorman
What an experienced grower watches for around here
In and around Middlesex County, two things run higher than the national average — Superfund (101 sites) and Toxic Release Inventory (290 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Toxic Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Middlesex 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
Middlesex 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 Middlesex County
Pull a site-specific report for your exact address in Middlesex County, New Jersey — 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 Middlesex County, New Jersey
- USDA Hardiness Zones: 7a (USDA PHZM 2023)
- Last Hard Freeze (28°F): Mar 19 (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: ~258 (county normal, NOAA 1991–2020 Climate Normals)
- County Land Area: 198K 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 Middlesex 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 Middlesex County, New Jersey?
Middlesex 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 Middlesex County?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Feb 19; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 19 (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. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
When does frost risk typically end in Middlesex County?
The last hard freeze (28°F) in Middlesex County typically lands around Mar 19, 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 Middlesex County?
Measured between 28°F hard freezes, Middlesex County sees about 258 frost-free days — roughly Mar 19 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 Middlesex County?
Middlesex County's zone 7a supports a wide range — strong performers include Tomato, Blueberry, Peach, Sweet Corn, and Cranberry. 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 Middlesex County, really?
Officially, Middlesex 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 Middlesex County?
The federal record around Middlesex County runs heavier than most — 4,027 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 Middlesex County — what should I know before planting?
Start with three facts. Middlesex County sits in USDA zone 7a, which sets what survives winter; the last 28°F hard freeze typically clears around Mar 19, with about 258 frost-free days to work with (NOAA 1991–2020 climate normals); and 4,027 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 Middlesex 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 Jersey's frost window, season length, and soil profile against the plant's real requirements.
