North Irwin, Pennsylvania, sits in USDA hardiness zone 6b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Well-matched crops include cabbage, hazelnut, lavender, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in North Irwin, 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 North Irwin 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 North Irwin — soil, climate, flood, and parcel records. How we handle your address.
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North Irwin — the short answer
North Irwin, Pennsylvania: USDA zone 6b, about 208 days between hard freezes, across 129 acres of town.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 10
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 4
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~208
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 129 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 North Irwin's average, not your lot's — a low corner or a tree line moves it. Against North Irwin's 208-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in North Irwin
Each reading below is measured for North Irwin itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredNorth Irwin runs about 208 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
MeasuredNorth Irwin 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 North Irwin is in
North Irwin sits in the Western Allegheny Plateau — EPA Level III, inside the wider Eastern Temperate Forests. That is read at North Irwin's own centroid rather than borrowed from Westmoreland County.
What Grows in North Irwin
Every plant below cleared North Irwin's own zone 6b and its 208-day season. Each card opens that plant's Pennsylvania profile. How we score.
Is it too late to plant in North Irwin?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Mar 13; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 10 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 4 — long-season crops need about 90 days of runway, quick greens only 30. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.
Documented around North Irwin
Spotted lanternfly documented 3 miles from North Irwin, first recorded 2019. What to watch for.
What's on the federal record near North Irwin
Closest first, within ~10 miles of North Irwin. Listing isn't leaking, and distance isn't exposure.
- IRWIN CONCRETE COUnderground Storage Tanks · 800 ft
- BRENTZEL MGMTUnderground Storage Tanks · 1800 ft
- PRECISION DEFENSE SVCBrownfields · 2100 ft
- FEDCO MFG INCBrownfields · 2300 ft
- INNOVATIVE CARBIDE/IRWINToxics Release Inventory · 2400 ft
- ABB POWER CIRCUT BREAKERBrownfields · 2400 ft
- SCHADE ICE COUnderground Storage Tanks · 0.5 mi
- WELTYS AUTO PARTSBrownfields · 0.5 mi
- IRWIN DRY CLEANERSBrownfields · 0.5 mi
- IRWIN BORO WESTMORELAND CNTYUnderground Storage Tanks · 0.6 mi
- ATLANTIC SERVICE STATIONBrownfields · 0.7 mi
- SUNOCO STAUnderground Storage Tanks · 0.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from North Irwin'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 North Irwin.
Total Sites
1,494
within ~10 miles of North Irwin
Risk Level
Elevated
Highest-severity
6 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of North Irwin
Severity Distribution
within ~10 miles of North Irwin
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •TRI facilities report what they release. Check the wind — downwind beds catch more of it.
Check your specific parcel in North Irwin
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 North Irwin average
Your land is one point inside North Irwin
Everything above resolves to North Irwin as a whole — one PHZM band and one 28°F frost record, read across 129 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 North Irwin Average
North Irwin Average
- ●USDA Zones 6b, averaged across North Irwin
- ●One soil character for all of North Irwin
- ●Frost dates read at North Irwin's scale: Apr 10 to Nov 4
YOUR Parcel
- ✓Your exact zone, not North Irwin's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in North Irwin
Pull a site-specific report for your exact address in North Irwin, Pennsylvania — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that North Irwin averages can't show:
We read public map data around North Irwin — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the North Irwin average
How we know this about North Irwin
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 North Irwin’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 North Irwin
When does frost risk typically end in North Irwin?
The last hard freeze (28°F) in North Irwin typically lands around Apr 10, 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 1.
When is the first frost in North Irwin?
The first hard freeze (28°F) in North Irwin typically arrives around Nov 4, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 21, so the watching starts about Oct 5 — about 208 days after the spring freeze cleared.
How long is the growing season in North Irwin?
Measured between 28°F hard freezes, North Irwin sees about 208 frost-free days — roughly Apr 10 through Nov 4, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 1 to Oct 21, about 173 days.
Is the soil safe to grow vegetables in North Irwin?
The federal record around North Irwin is a meaningful one — 1,494 documented sites, mostly Underground Storage Tanks entries (724), the nearest Underground Storage Tanks record about 0.2 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 North Irwin?
From about Oct 5 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 4 (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 4. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at North Irwin's scale — its 6b band and its 208-day season. Your yard writes its own version of North Irwin'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 North Irwin’s own scale
7 of the readings below were taken at North Irwin's own scale — its own ~208-day season between 28°F freezes, the 129 acres it covers and 1,494 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- North Irwin's own USDA hardiness band, zones 6bUSDA PHZM 2023
- North Irwin's own 28°F hard-freeze dates, about Apr 10 and Nov 4 and the ~208-day span between themNOAA 1991–2020 Climate Normals
- 1,494 documented contamination sites on the federal record near North Irwin, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- North Irwin's boundary and the 129 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~208-day seasonGrowable Ground crop-matching engine
- The ecoregion at North Irwin's own centroid, the Western Allegheny PlateauUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of North Irwinlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so North Irwin's 129 acres read through its county's SSURGO summaryfrom Westmoreland County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Westmoreland 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 Westmoreland County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among North Irwin's 129 acreswhy one lot differs from the next →
- Which side of North Irwin you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 129 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 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 North Irwin-wide figureread your own land →
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