Philadelphia, Pennsylvania, sits in USDA hardiness zone 7b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
These conditions suit cabbage, prickly pear, california poppy, and collard greens — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in Philadelphia, 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 Philadelphia 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 Philadelphia — soil, climate, flood, and parcel records. How we handle your address.
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Philadelphia — the short answer
Philadelphia, Pennsylvania: USDA zone 7b, about 250 days between hard freezes, across 86K acres of city.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 19
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 24
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~250
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 86K 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 7b is Philadelphia's average, not your lot's — a low corner or a tree line moves it. Against Philadelphia's 250-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Philadelphia
Each reading below is measured for Philadelphia itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredPhiladelphia runs about 250 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
MeasuredPhiladelphia sits in USDA hardiness zone 7b.
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 Philadelphia is in
Philadelphia sits in the Northern Piedmont — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Philadelphia's own centroid rather than borrowed from Philadelphia County.
What Grows in Philadelphia
Every plant below cleared Philadelphia's own zone 7b and its 250-day season. Each card opens that plant's Pennsylvania profile. How we score.
Is it too late to plant in Philadelphia?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Feb 19; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 19 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 24 — 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 Philadelphia
Spotted lanternfly documented 2 miles from Philadelphia, first recorded 2017. What to watch for.
What's on the federal record near Philadelphia
Closest first, within ~10 miles of Philadelphia. Listing isn't leaking, and distance isn't exposure.
- FORMER SLS TERM FREIGHT HANDLING FACUnderground Storage Tanks · 600 ft
- ROADRUNNER TRANSPORTATION SERVICESBrownfields · 650 ft
- TDPS MATERIALSUnderground Storage Tanks · 650 ft
- T D P S MATERIALS INCBrownfields · 700 ft
- NEW CATHEDRAL CEMETERYUnderground Storage Tanks · 700 ft
- P & W AUTO BODY SHOPBrownfields · 850 ft
- 220 PETER DEPAULUnderground Storage Tanks · 900 ft
- CLEMENTE SCHUnderground Storage Tanks · 950 ft
- PHILADELPHIA PRE COOKED STEAK COBrownfields · 1000 ft
- NORTH DIST WORK CTRUnderground Storage Tanks · 1100 ft
- FABRICON PRODUnderground Storage Tanks · 1100 ft
- MONTGOMERY TANK LINESUnderground Storage Tanks · 1100 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Philadelphia'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 Philadelphia.
Sources Checked
within ~10 miles of Philadelphia
Severity Distribution
within ~10 miles of Philadelphia
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Philadelphia, Superfund runs higher than the national average — 112 sites within ~10 miles of Philadelphia. 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.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Philadelphia
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 Philadelphia average
Your land is one point inside Philadelphia
Everything above resolves to Philadelphia as a whole — one PHZM band and one 28°F frost record, read across 86K 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 city 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 Philadelphia Average
Philadelphia Average
- ●USDA Zones 7b, averaged across Philadelphia
- ●One soil character for all of Philadelphia
- ●Frost dates read at Philadelphia's scale: Mar 19 to Nov 24
YOUR Parcel
- ✓Your exact zone, not Philadelphia's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Philadelphia
Pull a site-specific report for your exact address in Philadelphia, Pennsylvania — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Philadelphia averages can't show:
We read public map data around Philadelphia — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Philadelphia average
How we know this about Philadelphia
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Philadelphia’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 city grain anywhere on this page — there is no city-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 Philadelphia
When does frost risk typically end in Philadelphia?
The last hard freeze (28°F) in Philadelphia typically lands around Mar 19, 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 9.
When is the first frost in Philadelphia?
The first hard freeze (28°F) in Philadelphia typically arrives around Nov 24, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 10, so the watching starts about Oct 25 — about 250 days after the spring freeze cleared.
How long is the growing season in Philadelphia?
Measured between 28°F hard freezes, Philadelphia sees about 250 frost-free days — roughly Mar 19 through Nov 24, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 9 to Nov 10, about 215 days.
Is the soil safe to grow vegetables in Philadelphia?
The federal record around Philadelphia runs heavier than most — 6,392 documented sites, mostly Underground Storage Tanks entries (3,244), the nearest Underground Storage Tanks record about 0.1 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 Philadelphia?
From about Oct 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 Nov 24 (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 24. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Philadelphia's scale — its 7b band and its 250-day season. Your yard writes its own version of Philadelphia'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 Philadelphia’s own scale
7 of the readings below were taken at Philadelphia's own scale — its own ~250-day season between 28°F freezes, the 85,968 acres it covers and 6,392 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Philadelphia's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Philadelphia's own 28°F hard-freeze dates, about Mar 19 and Nov 24 and the ~250-day span between themNOAA 1991–2020 Climate Normals
- 6,392 documented contamination sites on the federal record near Philadelphia, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Philadelphia's boundary and the 85,968 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~250-day seasonGrowable Ground crop-matching engine
- The ecoregion at Philadelphia's own centroid, the Northern PiedmontUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Philadelphialydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Philadelphia's 85,968 acres read through its county's SSURGO summaryfrom Philadelphia County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Philadelphia 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 Philadelphia County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Philadelphia's 85,968 acreswhy one lot differs from the next →
- Which side of Philadelphia you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 85,968 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 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 Philadelphia-wide figureread your own land →