Hunterdon County, in New Jersey, sits in USDA hardiness zone 7a — a zone band wide enough that plant choice, not possibility, is the interesting question.
Growers here do well with cabbage, pawpaw, california poppy, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Hunterdon County holds more than one microclimate.
Soils and elevations shift across Hunterdon County, so your frost dates and drainage aren't the county average. Enter your address and we'll score 1,086 plants against your land's actual soil, sun, and frost.
We read public map data around Hunterdon County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Hunterdon County — the short answer
Hunterdon County, New Jersey: USDA zone 7a, about 208 days between hard freezes, across 274K acres.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 7
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 1
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~208
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 274K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 28°F normals: light frosts run a few weeks past them, and tender transplants usually wait 2–3 weeks after the last hard freeze.
Hardiness Zone Range
Zone 7a is Hunterdon County's average, not your lot's — a low corner or a tree line moves it. Against Hunterdon County's 208-day season, see what your own ground reads.
Heat in Hunterdon County
Across a year, Hunterdon County accumulates about 2,845 growing degree days above 50°F, about 477 fewer than the middle New Jersey county — ahead of 3 of New Jersey’s 21 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Hunterdon County
Across Hunterdon County, the ground is predominantly Alfisols, where Penn, Parker, and Chalfont are the most extensive named soil series. The soil is generally well drained with a silt loam surface. Topsoil pH runs about 5.0–5.3, strongly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Alfisols
Drainage
Well drained
Prime farmland
27%
Hydric soils
5%
Soil still varies lot by lot — soil types explained.
How the ground varies across Hunterdon County
The USDA soil survey maps 55% of Hunterdon County as well drained — but another 43% drains differently: 15% somewhat poorly drained, 13% somewhat excessively drained.
Penn is the most extensive named soil at 14% of mapped acres, then Parker (12%) and Chalfont (9%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Hunterdon County
Each reading below is measured for Hunterdon County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Hunterdon County are well drained, in hydrologic group C — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Hunterdon County runs about pH 5.0–5.3, on the acidic side.
Blueberries, potatoes, and rhododendrons thrive in it, but most vegetables start locking out nutrients below about pH 6.0 and grow pale and stunted no matter how much you feed them.
A measured lime application raises pH for the crops that need it — but test first, because the right rate depends on your own soil, not the county average.
USDA NRCS SSURGO
Season length
MeasuredHunterdon County runs about 208 days between hard freezes — a long growing season.
There is slack for succession plantings and slow-finishing crops: many vegetables can be sown twice, and the heat-lovers have time to ripen fully.
Plan a second sowing of quick crops after the first comes out, and use the fall window most gardeners let sit idle.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredHunterdon County sits in USDA hardiness zone 7a.
The zone sets which perennials, shrubs, and fruit trees live through an average winter here — a plant rated for a colder zone is a safe bet, one rated warmer needs winter protection or gets treated as an annual.
Match perennials and fruit to the zone before you buy, so nothing you plant is a gamble against the cold.
USDA PHZM 2023
The kind of country Hunterdon County is in
Hunterdon County spans 2 EPA Level III ecoregions — Northern Piedmont (78%) and Northeastern Highlands (21%). Which one your land falls in changes what grows wild there and how the ground behaves, and a county-wide answer cannot tell you which.
What Grows in Hunterdon County
We scored all 1,086 plants against Hunterdon County's own USDA zone 7a and its own 208-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's New Jersey profile.
Is it too late to plant in Hunterdon County?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 10; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 7 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 1 — 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.
Documented around Hunterdon County
Spotted lanternfly documented 2 miles from Hunterdon County, first recorded 2018. What to watch for.
- Japanese beetle5 documented records
- monarch butterfly62 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Hunterdon County
USGS estimates 17,174 lb of Glyphosate on Hunterdon County farmland in 2019, its largest by weight, ahead of Atrazine (9,739 lb) and Metolachlor & Metolachlor-s (6,839 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Hunterdon County — and how to grow with it.
We checked the federal record across Hunterdon County — 872 documented sites across 7 of the 9 source types we track.
The most significant on record: 25 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Hunterdon 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.
What's on the federal record near Hunterdon County
Closest first, across Hunterdon County. Listing isn't leaking, and distance isn't exposure.
- HUNTERDON TRANSFORMER COUnderground Storage Tanks · 1700 ft
- AT&T NJ 2440Underground Storage Tanks · 2500 ft
- AT&T COMMUNICATIONSUnderground Storage Tanks · 0.5 mi
- 190227-- DomesticNitrate · 0.7 mi
- NJDOT BRIDGE BLASTING PAINTINGBrownfields · 0.8 mi
- HUNTERDON TRANSFORMER COToxics Release Inventory · 0.9 mi
- COMERFORD DONALDBrownfields · 1.1 mi
- BROWN'S AUTO BODYUnderground Storage Tanks · 1.5 mi
- 190330-- Quakertown Sch MW-1Nitrate · 1.8 mi
- 190152-- DomNitrate · 2.0 mi
- 190565-- DomNitrate · 2.4 mi
- MYERS PROPERTYSuperfund · 2.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Hunterdon County's center, not your beds. Run your own address for what's upwind of you specifically.
Environmental Intelligence
The counts behind that headline — every source type on the record near Hunterdon County.
Sources Checked
across Hunterdon County
Severity Distribution
across Hunterdon County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Hunterdon County, two things run higher than the national average across Hunterdon County — Superfund (25 sites) and Nitrate (258 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.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Hunterdon County
Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,086 plant recommendations.
25+ data sources read at your address, not the Hunterdon County average
Your land is one point inside Hunterdon County
Everything above resolves to Hunterdon County as a whole — one PHZM band and one county frost record, read across 274K acres. Your parcel is one point inside that footprint. Slope, tree cover, a low spot that pools cold air, and what is in the soil are all resolved at the address, and none of them are visible at county scale. That is the honest boundary of this page, and the reason the next step is a reading of your own ground rather than a better county average.
Your Lot vs the Hunterdon County Average
Hunterdon County Average
- ●USDA Zones 7a, averaged across Hunterdon County
- ●One soil character for all of Hunterdon County
- ●Frost dates read at Hunterdon County's scale: Apr 7 to Nov 1
YOUR Parcel
- ✓Your exact zone, not Hunterdon County's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Hunterdon County
Pull a site-specific report for your exact address in Hunterdon County, New Jersey — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Hunterdon County averages can't show:
We read public map data around Hunterdon County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Hunterdon County average
How we know this about Hunterdon County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Hunterdon County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Hunterdon County
When does frost risk typically end in Hunterdon County?
The last hard freeze (28°F) in Hunterdon County typically lands around Apr 7, per NOAA 1991–2020 climate normals — earlier than the light-frost dates most charts quote. That marks the hard freeze, not the last light frost — lighter frosts keep biting past it, which is why tender transplants here wait until about Apr 28.
How long is the growing season in Hunterdon County?
Measured between 28°F hard freezes, Hunterdon County sees about 208 frost-free days — roughly Apr 7 through Nov 1, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 28 to Oct 18, about 173 days.
Is the soil safe to grow vegetables in Hunterdon County?
The federal record around Hunterdon County runs heavier than most — 872 documented sites, mostly Underground Storage Tanks entries (454), the nearest Underground Storage Tanks record about 0.3 miles out — 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.
Everything above is measured at Hunterdon County's scale — its 7a band and its 208-day season. Your yard writes its own version of Hunterdon County's numbers: 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.
What this page reads at Hunterdon County’s own scale
9 of the readings below were taken at Hunterdon County's own scale — its own ~208-day span between 28°F freezes, the 3 most extensive soil series mapped here and 872 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Hunterdon County's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Hunterdon County's own 28°F hard-freeze dates and its ~208-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Hunterdon CountyUSDA NRCS SSURGO
- 872 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.3 miles outFederal environmental registers
- Hunterdon County's boundary and the 273,814 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~208-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Hunterdon County spans, Northern Piedmont the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Hunterdon County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Hunterdon County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every New Jersey grower plans around — written at state scale, so they stay on the state guidefrom New Jersey
What this page can’t tell you
- How the season shifts across Hunterdon County — the ~208 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Hunterdon County's 273,814 acreswhy one lot differs from the next →
- Which of those 872 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Hunterdon Countyread your own land →