Clarendon, Pennsylvania, sits in USDA hardiness zone 6a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Reliable performers under these conditions include cabbage, blackberry, california poppy, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Clarendon, 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 Clarendon 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 Clarendon — soil, climate, flood, and parcel records. How we handle your address.
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Clarendon — the short answer
Clarendon, Pennsylvania: USDA zone 6a, about 169 days between hard freezes, across 216 acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- May 5
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 21
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~169
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 216 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 6a is Clarendon's average, not your lot's — a low corner or a tree line moves it. Against Clarendon's 169-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Clarendon
Each reading below is measured for Clarendon itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredClarendon runs about 169 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
MeasuredClarendon sits in USDA hardiness zone 6a.
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 Clarendon is in
Clarendon sits in the North Central Appalachians — EPA Level III, inside the wider Northern Forests. That is read at Clarendon's own centroid rather than borrowed from Warren County.
What Grows in Clarendon
Every plant below cleared Clarendon's own zone 6a and its 169-day season. Each card opens that plant's Pennsylvania profile. How we score.
Is it too late to plant in Clarendon?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Apr 7; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near May 5 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 21 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
Documented around Clarendon
Spotted lanternfly documented 4 miles from Clarendon, first recorded 2020. What to watch for.
What's on the federal record near Clarendon
Closest first, within ~10 miles of Clarendon. Listing isn't leaking, and distance isn't exposure.
- ALLEGHENY TOOL COBrownfields · 100 ft
- BERENFIELD CONTAINERS INC/CLARENDON PLTToxics Release Inventory · 850 ft
- RE BAKER & SONSUnderground Storage Tanks · 1500 ft
- CLARENDON FIRE DEPTUnderground Storage Tanks · 1500 ft
- M & D INDBrownfields · 1600 ft
- NIELSEN PAUL O INCBrownfields · 0.5 mi
- WR 357Nitrate · 1.2 mi
- CHAPMAN STATE PARKUnderground Storage Tanks · 1.2 mi
- KINZUA WOLF RUN MARINAUnderground Storage Tanks · 1.2 mi
- JOHNSONS TIRE SERVICE INCBrownfields · 1.5 mi
- IL GEER & SONSUnderground Storage Tanks · 1.6 mi
- KENS KEYSTONEUnderground Storage Tanks · 1.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Clarendon'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 Clarendon.
Total Sites
275
within ~10 miles of Clarendon
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Clarendon
Severity Distribution
within ~10 miles of Clarendon
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Clarendon, two things run higher than the national average within ~10 miles of Clarendon — Toxics Release Inventory (26 sites) and Nitrate (78 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Clarendon
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 Clarendon average
Your land is one point inside Clarendon
Everything above resolves to Clarendon as a whole — one PHZM band and one 28°F frost record, read across 216 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 Clarendon Average
Clarendon Average
- ●USDA Zones 6a, averaged across Clarendon
- ●One soil character for all of Clarendon
- ●Frost dates read at Clarendon's scale: May 5 to Oct 21
YOUR Parcel
- ✓Your exact zone, not Clarendon's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Clarendon
Pull a site-specific report for your exact address in Clarendon, Pennsylvania — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Clarendon averages can't show:
We read public map data around Clarendon — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Clarendon average
How we know this about Clarendon
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 Clarendon’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 Clarendon
When does frost risk typically end in Clarendon?
The last hard freeze (28°F) in Clarendon typically lands around May 5, 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 26.
When is the first frost in Clarendon?
The first hard freeze (28°F) in Clarendon typically arrives around Oct 21, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 7, so the watching starts about Sep 21 — about 169 days after the spring freeze cleared.
How long is the growing season in Clarendon?
Measured between 28°F hard freezes, Clarendon sees about 169 frost-free days — roughly May 5 through Oct 21, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 26 to Oct 7, about 134 days.
Is the soil safe to grow vegetables in Clarendon?
The federal record around Clarendon is a meaningful one — 275 documented sites, mostly Underground Storage Tanks entries (100), the nearest Brownfields record under a tenth of a mile out — so a soil test before new food beds is a sensible precaution here, not a reason to hold back from growing. Remember that proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what sits where.
How do I protect my plants from frost in Clarendon?
From about Sep 21 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 21 (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 21. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Clarendon's scale — its 6a band and its 169-day season. Your yard writes its own version of Clarendon'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 Clarendon’s own scale
7 of the readings below were taken at Clarendon's own scale — its own ~169-day season between 28°F freezes, the 216 acres it covers and 275 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Clarendon's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Clarendon's own 28°F hard-freeze dates, about May 5 and Oct 21 and the ~169-day span between themNOAA 1991–2020 Climate Normals
- 275 documented contamination sites on the federal record near Clarendon, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- Clarendon's boundary and the 216 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~169-day seasonGrowable Ground crop-matching engine
- The ecoregion at Clarendon's own centroid, the North Central AppalachiansUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Clarendonlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Clarendon's 216 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 Pennsylvania grower plans around — written at state scale, so they stay on the state guidefrom Pennsylvania
- 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 Clarendon's 216 acreswhy one lot differs from the next →
- Which side of Clarendon you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 216 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record under a tenth of a mile 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 Clarendon-wide figureread your own land →
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