South New Castle, Pennsylvania, sits in USDA hardiness zone 6b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
The conditions favor cabbage, blackberry, california poppy, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in South New Castle, 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 South New Castle 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 South New Castle — soil, climate, flood, and parcel records. How we handle your address.
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South New Castle — the short answer
South New Castle, Pennsylvania: USDA zone 6b, about 195 days between hard freezes, across 207 acres of town.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 18
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 30
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~195
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 207 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 South New Castle's average, not your lot's — a low corner or a tree line moves it. Against South New Castle's 195-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in South New Castle
Each reading below is measured for South New Castle itself — here is what it means for a garden here, and the move an experienced grower makes about it.

Season length
MeasuredSouth New Castle runs about 195 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
MeasuredSouth New Castle 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 South New Castle is in
South New Castle sits in the Erie Drift Plain — EPA Level III, inside the wider Eastern Temperate Forests. That is read at South New Castle's own centroid rather than borrowed from Lawrence County.
What Grows in South New Castle
Every plant below cleared South New Castle's own zone 6b and its 195-day season. Each card opens that plant's Pennsylvania profile. How we score.






























Is it too late to plant in South New Castle?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 21; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 18 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 30 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
Documented around South New Castle
Spotted lanternfly documented 1 miles from South New Castle, first recorded 2020. What to watch for.
What's on the federal record near South New Castle
Closest first, within ~10 miles of South New Castle. Listing isn't leaking, and distance isn't exposure.
- NEW CASTLE YARDUnderground Storage Tanks · 2200 ft
- GULF OIL GAS STAUnderground Storage Tanks · 0.6 mi
- NEW CASTLE FOUNDRY/NEW CASTLEToxics Release Inventory · 0.7 mi
- CASTLE BLDR SUPPLYUnderground Storage Tanks · 0.7 mi
- HUSTON INCUnderground Storage Tanks · 0.7 mi
- ROCKWELL INTLUnderground Storage Tanks · 0.7 mi
- ROCKWELL INTL CORPToxics Release Inventory · 0.7 mi
- BPI INC - NEW CASTLE PLANTToxics Release Inventory · 0.7 mi
- CASTLE BRANDUnderground Storage Tanks · 0.7 mi
- NEW CASTLE FOUNDRY COUnderground Storage Tanks · 0.8 mi
- CASCADE EXPRESSUnderground Storage Tanks · 0.8 mi
- NEW CASTLE TRANSIT AUTHUnderground Storage Tanks · 0.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from South New Castle'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 South New Castle.
Total Sites
479
within ~10 miles of South New Castle
Risk Level
Elevated
Highest-severity
3 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of South New Castle
Severity Distribution
within ~10 miles of South New Castle
Highest-Severity Sites

A note from Gnorman
What an experienced grower watches for around here
In and around South New Castle, Toxics Release Inventory runs higher than the national average — 47 sites within ~10 miles of South New Castle. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in South New Castle
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 South New Castle average
Your land is one point inside South New Castle
Everything above resolves to South New Castle as a whole — one PHZM band and one 28°F frost record, read across 207 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 South New Castle Average
South New Castle Average
- ●USDA Zones 6b, averaged across South New Castle
- ●One soil character for all of South New Castle
- ●Frost dates read at South New Castle's scale: Apr 18 to Oct 30
YOUR Parcel
- ✓Your exact zone, not South New Castle's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in South New Castle
Pull a site-specific report for your exact address in South New Castle, Pennsylvania — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that South New Castle averages can't show:
We read public map data around South New Castle — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the South New Castle average
How we know this about South New Castle
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 South New Castle’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 South New Castle
When does frost risk typically end in South New Castle?
The last hard freeze (28°F) in South New Castle typically lands around Apr 18, 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 9.
When is the first frost in South New Castle?
The first hard freeze (28°F) in South New Castle typically arrives around Oct 30, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 16, so the watching starts about Sep 30 — about 195 days after the spring freeze cleared.
How long is the growing season in South New Castle?
Measured between 28°F hard freezes, South New Castle sees about 195 frost-free days — roughly Apr 18 through Oct 30, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 9 to Oct 16, about 160 days.
Is the soil safe to grow vegetables in South New Castle?
The federal record around South New Castle is a meaningful one — 479 documented sites, mostly Underground Storage Tanks entries (233), the nearest Underground Storage Tanks record about 0.4 miles 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 South New Castle?
From about Sep 30 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 30 (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 30. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at South New Castle's scale — its 6b band and its 195-day season. Your yard writes its own version of South New Castle'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 South New Castle’s own scale
7 of the readings below were taken at South New Castle's own scale — its own ~195-day season between 28°F freezes, the 207 acres it covers and 479 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- South New Castle's own USDA hardiness band, zones 6bUSDA PHZM 2023
- South New Castle's own 28°F hard-freeze dates, about Apr 18 and Oct 30 and the ~195-day span between themNOAA 1991–2020 Climate Normals
- 479 documented contamination sites on the federal record near South New Castle, the closest Underground Storage Tanks record about 0.4 miles out from the town centreFederal environmental registers
- South New Castle's boundary and the 207 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~195-day seasonGrowable Ground crop-matching engine
- The ecoregion at South New Castle's own centroid, the Erie Drift PlainUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of South New Castlelydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so South New Castle's 207 acres read through its county's SSURGO summaryfrom Lawrence County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Lawrence 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 Lawrence County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among South New Castle's 207 acreswhy one lot differs from the next →
- Which side of South New Castle you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 207 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.4 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 South New Castle-wide figureread your own land →
More in Pennsylvania
Wider growing context
What grows across PennsylvaniaSouth New Castle sits outside our named growing regions, so Pennsylvania as a whole is its closest context here.
Nearby growing guides
