Upper Stewartsville, 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, hazelnut, california poppy, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Upper Stewartsville, 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 Upper Stewartsville 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 Upper Stewartsville — soil, climate, flood, and parcel records. How we handle your address.
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Upper Stewartsville — the short answer
Upper Stewartsville, New Jersey: USDA zone 7a, about 212 days between hard freezes, across 224 acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 6
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 4
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~212
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 224 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 7a is Upper Stewartsville's average, not your lot's — a low corner or a tree line moves it. Against Upper Stewartsville's 212-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Upper Stewartsville
Each reading below is measured for Upper Stewartsville itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredUpper Stewartsville runs about 212 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
MeasuredUpper Stewartsville 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 Upper Stewartsville is in
Upper Stewartsville sits in the Ridge and Valley — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Upper Stewartsville's own centroid rather than borrowed from Warren County.
What Grows in Upper Stewartsville
Every plant below cleared Upper Stewartsville's own zone 7a and its 212-day season. Each card opens that plant's New Jersey profile. How we score.
Is it too late to plant in Upper Stewartsville?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 9; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 6 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 4 — 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 Upper Stewartsville
Spotted lanternfly documented 3 miles from Upper Stewartsville, first recorded 2017. What to watch for.
What's on the federal record near Upper Stewartsville
Closest first, within ~10 miles of Upper Stewartsville. Listing isn't leaking, and distance isn't exposure.
- STEWARTSVILLE SERVICEUnderground Storage Tanks · 950 ft
- RAYNA TRANSPORTATION INCUnderground Storage Tanks · 2300 ft
- VERNON MOTORS INCUnderground Storage Tanks · 0.6 mi
- GREENWICH TWPUnderground Storage Tanks · 1.3 mi
- AQUA NJ - PHILLIPSBURGPFAS · 1.6 mi
- 7-UP BOTTLING OF WASHUnderground Storage Tanks · 1.6 mi
- BROADWAY AUTOMOTIVE SERVICE & SALESUnderground Storage Tanks · 1.6 mi
- FEILBACH WELDING SERVICEUnderground Storage Tanks · 1.6 mi
- WICKES LUMBER COUnderground Storage Tanks · 1.7 mi
- GLOBAL COMPUTER PRO CORPBrownfields · 1.7 mi
- DETRICK CABINET SHOP INCUnderground Storage Tanks · 1.7 mi
- QUALITY OUTFITTERSUnderground Storage Tanks · 1.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Upper Stewartsville'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 Upper Stewartsville.
Total Sites
928
within ~10 miles of Upper Stewartsville
Risk Level
High
Highest-severity
16 Superfund sites
Sources Checked
within ~10 miles of Upper Stewartsville
Severity Distribution
within ~10 miles of Upper Stewartsville
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Upper Stewartsville, two things run higher than the national average within ~10 miles of Upper Stewartsville — Superfund (16 sites) and Toxics Release Inventory (65 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.
Toxics 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 Upper Stewartsville
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 Upper Stewartsville average
Your land is one point inside Upper Stewartsville
Everything above resolves to Upper Stewartsville as a whole — one PHZM band and one 28°F frost record, read across 224 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 Upper Stewartsville Average
Upper Stewartsville Average
- ●USDA Zones 7a, averaged across Upper Stewartsville
- ●One soil character for all of Upper Stewartsville
- ●Frost dates read at Upper Stewartsville's scale: Apr 6 to Nov 4
YOUR Parcel
- ✓Your exact zone, not Upper Stewartsville's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Upper Stewartsville
Pull a site-specific report for your exact address in Upper Stewartsville, New Jersey — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Upper Stewartsville averages can't show:
We read public map data around Upper Stewartsville — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Upper Stewartsville average
How we know this about Upper Stewartsville
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 Upper Stewartsville’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 Upper Stewartsville
When does frost risk typically end in Upper Stewartsville?
The last hard freeze (28°F) in Upper Stewartsville typically lands around Apr 6, 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 27.
When is the first frost in Upper Stewartsville?
The first hard freeze (28°F) in Upper Stewartsville typically arrives around Nov 4, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 21, so the watching starts about Oct 5 — about 212 days after the spring freeze cleared.
How long is the growing season in Upper Stewartsville?
Measured between 28°F hard freezes, Upper Stewartsville sees about 212 frost-free days — roughly Apr 6 through Nov 4, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 27 to Oct 21, about 177 days.
Is the soil safe to grow vegetables in Upper Stewartsville?
The federal record around Upper Stewartsville runs heavier than most — 928 documented sites, mostly Underground Storage Tanks entries (536), the nearest Underground Storage Tanks record about 0.2 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 Upper Stewartsville?
From about Oct 5 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 Nov 4 (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 Nov 4. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Upper Stewartsville's scale — its 7a band and its 212-day season. Your yard writes its own version of Upper Stewartsville'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 Upper Stewartsville’s own scale
7 of the readings below were taken at Upper Stewartsville's own scale — its own ~212-day season between 28°F freezes, the 224 acres it covers and 928 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Upper Stewartsville's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Upper Stewartsville's own 28°F hard-freeze dates, about Apr 6 and Nov 4 and the ~212-day span between themNOAA 1991–2020 Climate Normals
- 928 documented contamination sites on the federal record near Upper Stewartsville, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Upper Stewartsville's boundary and the 224 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~212-day seasonGrowable Ground crop-matching engine
- The ecoregion at Upper Stewartsville's own centroid, the Ridge and ValleyUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Upper Stewartsvillelydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Upper Stewartsville's 224 acres read through its county's SSURGO summaryfrom Warren County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Warren 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 Warren County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Upper Stewartsville's 224 acreswhy one lot differs from the next →
- Which side of Upper Stewartsville you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 224 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 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 Upper Stewartsville-wide figureread your own land →