Castle Shannon, Pennsylvania, sits in USDA hardiness zone 6b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
These conditions suit cabbage, hazelnut, lavender, and collard greens — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in Castle Shannon, 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 Castle Shannon 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 Castle Shannon — soil, climate, flood, and parcel records. How we handle your address.
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Castle Shannon — the short answer
Castle Shannon, Pennsylvania: USDA zone 6b, about 222 days between hard freezes, across 1K acres of town.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 2
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 10
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~222
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 1K 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 Castle Shannon's average, not your lot's — a low corner or a tree line moves it. Against Castle Shannon's 222-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Castle Shannon
Each reading below is measured for Castle Shannon itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredCastle Shannon runs about 222 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
MeasuredCastle Shannon 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 Castle Shannon is in
Castle Shannon sits in the Western Allegheny Plateau — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Castle Shannon's own centroid rather than borrowed from Allegheny County.
What Grows in Castle Shannon
Every plant below cleared Castle Shannon's own zone 6b and its 222-day season. Each card opens that plant's Pennsylvania profile. How we score.
Is it too late to plant in Castle Shannon?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 5; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 2 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 10 — 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 Castle Shannon
Spotted lanternfly documented 1 miles from Castle Shannon, first recorded 2019. What to watch for.
What's on the federal record near Castle Shannon
Closest first, within ~10 miles of Castle Shannon. Listing isn't leaking, and distance isn't exposure.
- KOEHNKE FLOORINGUnderground Storage Tanks · 100 ft
- MARGARET DAUBE PROPUnderground Storage Tanks · 400 ft
- PRASHANT MINIMARTUnderground Storage Tanks · 550 ft
- GREASE MONKEY 149Underground Storage Tanks · 600 ft
- CENTERLINE COLLISIONBrownfields · 600 ft
- SHERWIN WILLIAMS NO 1268Brownfields · 600 ft
- THREE CTR INDEPENDENT OILUnderground Storage Tanks · 900 ft
- EXXON FACILITY LIBRARY ROADBrownfields · 950 ft
- EXXON RS 2 0456Underground Storage Tanks · 1100 ft
- DRAPERY MASTERBrownfields · 1200 ft
- 7 ELEVEN 40172Underground Storage Tanks · 1300 ft
- SUNOCO SVC STABrownfields · 1300 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Castle Shannon'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 Castle Shannon.
Total Sites
2,852
within ~10 miles of Castle Shannon
Risk Level
Elevated
Highest-severity
18 Superfund sites
Sources Checked
within ~10 miles of Castle Shannon
Severity Distribution
within ~10 miles of Castle Shannon
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 Castle Shannon
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 Castle Shannon average
Your land is one point inside Castle Shannon
Everything above resolves to Castle Shannon as a whole — one PHZM band and one 28°F frost record, read across 1K 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 Castle Shannon Average
Castle Shannon Average
- ●USDA Zones 6b, averaged across Castle Shannon
- ●One soil character for all of Castle Shannon
- ●Frost dates read at Castle Shannon's scale: Apr 2 to Nov 10
YOUR Parcel
- ✓Your exact zone, not Castle Shannon's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Castle Shannon
Pull a site-specific report for your exact address in Castle Shannon, Pennsylvania — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Castle Shannon averages can't show:
We read public map data around Castle Shannon — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Castle Shannon average
How we know this about Castle Shannon
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 Castle Shannon’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 Castle Shannon
When does frost risk typically end in Castle Shannon?
The last hard freeze (28°F) in Castle Shannon typically lands around Apr 2, 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 23.
When is the first frost in Castle Shannon?
The first hard freeze (28°F) in Castle Shannon typically arrives around Nov 10, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 27, so the watching starts about Oct 11 — about 222 days after the spring freeze cleared.
How long is the growing season in Castle Shannon?
Measured between 28°F hard freezes, Castle Shannon sees about 222 frost-free days — roughly Apr 2 through Nov 10, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 23 to Oct 27, about 187 days.
Is the soil safe to grow vegetables in Castle Shannon?
The federal record around Castle Shannon is a meaningful one — 2,852 documented sites, mostly Underground Storage Tanks entries (1,384), the nearest Underground Storage Tanks 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 Castle Shannon?
From about Oct 11 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 10 (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 10. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Castle Shannon's scale — its 6b band and its 222-day season. Your yard writes its own version of Castle Shannon'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 Castle Shannon’s own scale
7 of the readings below were taken at Castle Shannon's own scale — its own ~222-day season between 28°F freezes, the 1,023 acres it covers and 2,852 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Castle Shannon's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Castle Shannon's own 28°F hard-freeze dates, about Apr 2 and Nov 10 and the ~222-day span between themNOAA 1991–2020 Climate Normals
- 2,852 documented contamination sites on the federal record near Castle Shannon, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Castle Shannon's boundary and the 1,023 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~222-day seasonGrowable Ground crop-matching engine
- The ecoregion at Castle Shannon's own centroid, the Western Allegheny PlateauUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Castle Shannonlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Castle Shannon's 1,023 acres read through its county's SSURGO summaryfrom Allegheny County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Allegheny 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 Allegheny County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Castle Shannon's 1,023 acreswhy one lot differs from the next →
- Which side of Castle Shannon you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,023 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks 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 Castle Shannon-wide figureread your own land →