Hewitt, New Jersey, sits in USDA hardiness zone 6b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
On paper, cabbage, hazelnut, lavender, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Hewitt, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Hewitt lot. 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 Hewitt — soil, climate, flood, and parcel records. How we handle your address.
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Hewitt — the short answer
Hewitt, New Jersey: USDA zone 6b, about 202 days between hard freezes, across 3K acres of town.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 10
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 29
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~202
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 3K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 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 6b is Hewitt's average, not your lot's — a low corner or a tree line moves it. Against Hewitt's 202-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Hewitt
Each reading below is measured for Hewitt itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHewitt runs about 202 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
MeasuredHewitt sits in USDA hardiness zone 6b.
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 Hewitt is in
Hewitt sits in the Northeastern Highlands — EPA Level III, inside the wider Northern Forests. That is read at Hewitt's own centroid rather than borrowed from Passaic County.
What Grows in Hewitt
Every plant below cleared Hewitt's own zone 6b and its 202-day season. Each card opens that plant's New Jersey profile. How we score.
Is it too late to plant in Hewitt?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 13; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 10 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 29 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
Documented around Hewitt
Spotted lanternfly documented 1 miles from Hewitt, first recorded 2021. What to watch for.
What's on the federal record near Hewitt
Closest first, within ~10 miles of Hewitt. Listing isn't leaking, and distance isn't exposure.
- HAPPY LANDING MARINAUnderground Storage Tanks · 2000 ft
- O7842Nitrate · 0.8 mi
- SPORTSMANS MARINA LLCUnderground Storage Tanks · 0.8 mi
- GREENWOOD LAKE BOAT BASIN INCUnderground Storage Tanks · 0.8 mi
- MOOSEHEAD MARINEUnderground Storage Tanks · 1.1 mi
- SULLYS MARINE LLCUnderground Storage Tanks · 1.1 mi
- 310060-- PW 4Nitrate · 1.2 mi
- AWOSTING WELL 1 & 4Brownfields · 1.3 mi
- 310055-- Awosting 3 - Wm 3040Nitrate · 1.8 mi
- VWNJ AWOSTING WWTPBrownfields · 1.9 mi
- VWNJ GREENBROOK WTPBrownfields · 2.0 mi
- GREENBROOK WELL HOUSE NO 2Underground Storage Tanks · 2.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Hewitt'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 Hewitt.
Sources Checked
within ~10 miles of Hewitt
Severity Distribution
within ~10 miles of Hewitt
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Hewitt, two things run higher than the national average within ~10 miles of Hewitt — PFAS (8 sites) and Superfund (7 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Hewitt
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 Hewitt average
Your land is one point inside Hewitt
Everything above resolves to Hewitt as a whole — one PHZM band and one 28°F frost record, read across 3K 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 town 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 local average.
Your Lot vs the Hewitt Average
Hewitt Average
- ●USDA Zones 6b, averaged across Hewitt
- ●One soil character for all of Hewitt
- ●Frost dates read at Hewitt's scale: Apr 10 to Oct 29
YOUR Parcel
- ✓Your exact zone, not Hewitt's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Hewitt
Pull a site-specific report for your exact address in Hewitt, New Jersey — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Hewitt averages can't show:
We read public map data around Hewitt — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Hewitt average
How we know this about Hewitt
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Hewitt’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at town grain anywhere on this page — there is no town-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Hewitt
When does frost risk typically end in Hewitt?
The last hard freeze (28°F) in Hewitt typically lands around Apr 10, 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 May 1.
When is the first frost in Hewitt?
The first hard freeze (28°F) in Hewitt typically arrives around Oct 29, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 15, so the watching starts about Sep 29 — about 202 days after the spring freeze cleared.
How long is the growing season in Hewitt?
Measured between 28°F hard freezes, Hewitt sees about 202 frost-free days — roughly Apr 10 through Oct 29, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 1 to Oct 15, about 167 days.
Is the soil safe to grow vegetables in Hewitt?
The federal record around Hewitt runs heavier than most — 452 documented sites, mostly Underground Storage Tanks entries (221), the nearest Underground Storage Tanks record about 0.4 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.
How do I protect my plants from frost in Hewitt?
From about Sep 29 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Oct 29 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Oct 29. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Hewitt's scale — its 6b band and its 202-day season. Your yard writes its own version of Hewitt's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Hewitt’s own scale
7 of the readings below were taken at Hewitt's own scale — its own ~202-day season between 28°F freezes, the 2,958 acres it covers and 452 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Hewitt's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Hewitt's own 28°F hard-freeze dates, about Apr 10 and Oct 29 and the ~202-day span between themNOAA 1991–2020 Climate Normals
- 452 documented contamination sites on the federal record near Hewitt, the closest Underground Storage Tanks record about 0.4 miles out from the town centreFederal environmental registers
- Hewitt's boundary and the 2,958 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~202-day seasonGrowable Ground crop-matching engine
- The ecoregion at Hewitt's own centroid, the Northeastern HighlandsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Hewittlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Hewitt's 2,958 acres read through its county's SSURGO summaryfrom Passaic County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Passaic County
- The growing challenges every New Jersey grower plans around — written at state scale, so they stay on the state guidefrom New Jersey
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Passaic County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Hewitt's 2,958 acreswhy one lot differs from the next →
- Which side of Hewitt you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 2,958 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.4 miles out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Hewitt-wide figureread your own land →
More in New Jersey
Wider growing context
What grows across New JerseyHewitt sits outside our named growing regions, so New Jersey as a whole is its closest context here.
Nearby growing guides