Mendham, New Jersey, sits in USDA hardiness zone 6b — 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 cabbage, hazelnut, lavender, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Mendham, 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 Mendham 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 Mendham — soil, climate, flood, and parcel records. How we handle your address.
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Mendham — the short answer
Mendham, New Jersey: USDA zone 6b, about 196 days between hard freezes, across 4K acres of town.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 12
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 25
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~196
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 4K 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 Mendham's average, not your lot's — a low corner or a tree line moves it. Against Mendham's 196-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Mendham
Each reading below is measured for Mendham itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredMendham runs about 196 days between hard freezes — a moderate growing season.
There is room for the full run of cool-season crops plus a warm-season main crop, but the calendar is tight enough that a late spring or early fall frost still decides how much finishes.
Time warm-season transplants to your last hard freeze, and a few weeks of season extension turns a near-miss harvest into a sure one.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredMendham 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 Mendham is in
Mendham sits in the Northeastern Highlands — EPA Level III, inside the wider Northern Forests. That is read at Mendham's own centroid rather than borrowed from Morris County.
What Grows in Mendham
Every plant below cleared Mendham's own zone 6b and its 196-day season. Each card opens that plant's New Jersey profile. How we score.
Is it too late to plant in Mendham?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 15; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 12 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 25 — long-season crops need about 90 days of runway, quick greens only 30. As the window narrows, the plantings just get faster — fall brassicas, then greens, then garlic to finish.
Documented around Mendham
Spotted lanternfly documented 3 miles from Mendham, first recorded 2020. What to watch for.
What's on the federal record near Mendham
Closest first, within ~10 miles of Mendham. Listing isn't leaking, and distance isn't exposure.
- 271139-- Mendham Test4-FranklinNitrate · 0.6 mi
- SUNOCO SERVICE STATION (FORMER)Underground Storage Tanks · 0.6 mi
- STILES SERVICE STATION FORMERUnderground Storage Tanks · 0.6 mi
- 29 EAST MAIN REALTY LLCUnderground Storage Tanks · 0.7 mi
- GUNTHER'S EXXONUnderground Storage Tanks · 0.7 mi
- MR JAMES THOMASUnderground Storage Tanks · 0.7 mi
- MENDHAM VILLAGE SHOPPING CENTERUnderground Storage Tanks · 0.7 mi
- WEST MORRIS MENDHAM HIGH SCHOOLBrownfields · 0.8 mi
- DONALD GESELL INCUnderground Storage Tanks · 0.9 mi
- SISTERS OF CHRISTIAN CHARITYUnderground Storage Tanks · 0.9 mi
- KINGS 3630Brownfields · 1.1 mi
- CVS PHARMACY #11204Brownfields · 1.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Mendham'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 Mendham.
Sources Checked
within ~10 miles of Mendham
Severity Distribution
within ~10 miles of Mendham
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Mendham, two things run higher than the national average within ~10 miles of Mendham — Superfund (39 sites) and PFAS (17 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Superfund: Superfund sites represent the most severe contamination in the federal system.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Mendham
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 Mendham average
Your land is one point inside Mendham
Everything above resolves to Mendham as a whole — one PHZM band and one 28°F frost record, read across 4K 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 Mendham Average
Mendham Average
- ●USDA Zones 6b, averaged across Mendham
- ●One soil character for all of Mendham
- ●Frost dates read at Mendham's scale: Apr 12 to Oct 25
YOUR Parcel
- ✓Your exact zone, not Mendham's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Mendham
Pull a site-specific report for your exact address in Mendham, New Jersey — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Mendham averages can't show:
We read public map data around Mendham — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Mendham average
How we know this about Mendham
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 Mendham’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 Mendham
When does frost risk typically end in Mendham?
The last hard freeze (28°F) in Mendham typically lands around Apr 12, 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 3.
When is the first frost in Mendham?
The first hard freeze (28°F) in Mendham typically arrives around Oct 25, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 11, so the watching starts about Sep 25 — about 196 days after the spring freeze cleared.
How long is the growing season in Mendham?
Measured between 28°F hard freezes, Mendham sees about 196 frost-free days — roughly Apr 12 through Oct 25, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 3 to Oct 11, about 161 days.
Is the soil safe to grow vegetables in Mendham?
The federal record around Mendham runs heavier than most — 1,495 documented sites, mostly Underground Storage Tanks entries (874), the nearest Nitrate record about 0.6 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 Mendham?
From about Sep 25 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 25 (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 25. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Mendham's scale — its 6b band and its 196-day season. Your yard writes its own version of Mendham'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 Mendham’s own scale
7 of the readings below were taken at Mendham's own scale — its own ~196-day season between 28°F freezes, the 3,795 acres it covers and 1,495 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Mendham's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Mendham's own 28°F hard-freeze dates, about Apr 12 and Oct 25 and the ~196-day span between themNOAA 1991–2020 Climate Normals
- 1,495 documented contamination sites on the federal record near Mendham, the closest Nitrate record about 0.6 miles out from the town centreFederal environmental registers
- Mendham's boundary and the 3,795 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~196-day seasonGrowable Ground crop-matching engine
- The ecoregion at Mendham's own centroid, the Northeastern HighlandsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Mendhamlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Mendham's 3,795 acres read through its county's SSURGO summaryfrom Morris County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Morris 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 Morris County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Mendham's 3,795 acreswhy one lot differs from the next →
- Which side of Mendham you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,795 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.6 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 Mendham-wide figureread your own land →