Philadelphia County, in 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.
Philadelphia County lies within Greater Philadelphia — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Philadelphia County holds more than one microclimate.
Soils and elevations shift across Philadelphia County, so your frost dates and drainage aren't the county average. 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 County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Philadelphia County — the short answer
Philadelphia County, Pennsylvania: USDA zone 7b, about 250 days between hard freezes, across 86K acres.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 19
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 24
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~250
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 86K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 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 County's average, not your lot's — a low corner or a tree line moves it. Against Philadelphia County's 250-day season, see what your own ground reads.
Heat in Philadelphia County
Across a year, Philadelphia County accumulates about 3,889 growing degree days above 50°F, about 1,342 more than the middle Pennsylvania county — ahead of every other Pennsylvania county. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Philadelphia County
Across Philadelphia County, the ground is predominantly Ultisols, where Chester, Manor, and Howell are the most extensive named soil series. The soil is generally well drained with a variable surface. Topsoil pH runs about 5.4, strongly acidic. Rainfall drains through hydrologic group B soils.
Soil order
Ultisols
Drainage
Well drained
Prime farmland
4%
Hydric soils
8%
Soil still varies lot by lot — soil types explained.
How the ground varies across Philadelphia County
The USDA soil survey maps 8% of Philadelphia County as well drained — but another 3% drains differently: 1% poorly drained, 1% moderately well drained.
Chester is the most extensive named soil at 51% of mapped acres, then Manor (22%) and Howell (8%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Philadelphia County
Each reading below is measured for Philadelphia County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Philadelphia County are well drained, in hydrologic group B — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Philadelphia County runs about pH 5.4, on the acidic side.
Blueberries, potatoes, and rhododendrons thrive in it, but most vegetables start locking out nutrients below about pH 6.0 and grow pale and stunted no matter how much you feed them.
A measured lime application raises pH for the crops that need it — but test first, because the right rate depends on your own soil, not the county average.
USDA NRCS SSURGO
Season length
MeasuredPhiladelphia County 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 County 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 County is in
Philadelphia County spans 2 EPA Level III ecoregions — Northern Piedmont (56%) and Middle Atlantic Coastal Plain (44%). Which one your land falls in changes what grows wild there and how the ground behaves, and a county-wide answer cannot tell you which.
What Grows in Philadelphia County
We scored all 1,086 plants against Philadelphia County's own USDA zone 7b and its own 250-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's Pennsylvania profile.
Is it too late to plant in Philadelphia County?
Almost never — the real question is what to plant next. 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 County
Spotted lanternfly documented 2 miles from Philadelphia County, first recorded 2017. What to watch for.
- Japanese beetle27 documented records
- monarch butterfly258 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Philadelphia County
USGS estimates 19 lb of Glyphosate on Philadelphia County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (17 lb) and Metolachlor-s (14 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Philadelphia County — and how to grow with it.
We checked the federal record across Philadelphia County — 3,681 documented sites across 7 of the 9 source types we track.
The most significant on record: 48 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Philadelphia County carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Philadelphia County
Closest first, across Philadelphia County. 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 County'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 County.
Sources Checked
across Philadelphia County
Severity Distribution
across Philadelphia County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Philadelphia County, Superfund runs higher than the national average — 48 sites across Philadelphia County. 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 County
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 County average
Your land is one point inside Philadelphia County
Everything above resolves to Philadelphia County as a whole — one PHZM band and one county 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 county 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 county average.
Your Lot vs the Philadelphia County Average
Philadelphia County Average
- ●USDA Zones 7b, averaged across Philadelphia County
- ●One soil character for all of Philadelphia County
- ●Frost dates read at Philadelphia County's scale: Mar 19 to Nov 24
YOUR Parcel
- ✓Your exact zone, not Philadelphia County's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Philadelphia County
Pull a site-specific report for your exact address in Philadelphia County, Pennsylvania — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Philadelphia County averages can't show:
We read public map data around Philadelphia County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Philadelphia County average
How we know this about Philadelphia County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Philadelphia County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Philadelphia County
When does frost risk typically end in Philadelphia County?
The last hard freeze (28°F) in Philadelphia County 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.
How long is the growing season in Philadelphia County?
Measured between 28°F hard freezes, Philadelphia County 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 County?
The federal record around Philadelphia County runs heavier than most — 3,681 documented sites, mostly Underground Storage Tanks entries (1,701), 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.
Everything above is measured at Philadelphia County's scale — its 7b band and its 250-day season. Your yard writes its own version of Philadelphia County's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads Pennsylvania's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Philadelphia County’s own scale
9 of the readings below were taken at Philadelphia County's own scale — its own ~250-day span between 28°F freezes, the 3 most extensive soil series mapped here and 3,681 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Philadelphia County's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Philadelphia County's own 28°F hard-freeze dates and its ~250-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Philadelphia CountyUSDA NRCS SSURGO
- 3,681 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.1 miles outFederal environmental registers
- Philadelphia County'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 2 ecoregions Philadelphia County spans, Northern Piedmont the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Philadelphia County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Philadelphia County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Pennsylvania grower plans around — written at state scale, so they stay on the state guidefrom Pennsylvania
What this page can’t tell you
- How the season shifts across Philadelphia County — the ~250 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Philadelphia County's 85,968 acreswhy one lot differs from the next →
- Which of those 3,681 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Philadelphia Countyread your own land →