Sligo, Pennsylvania, sits in USDA hardiness zone 6a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Reliable performers under these conditions include cabbage, hazelnut, lavender, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Sligo, 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 Sligo 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 Sligo — soil, climate, flood, and parcel records. How we handle your address.
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Sligo — the short answer
Sligo, Pennsylvania: USDA zone 6a, about 184 days between hard freezes, across 900 acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 27
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 28
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~184
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 900 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 6a is Sligo's average, not your lot's — a low corner or a tree line moves it. Against Sligo's 184-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Sligo
Each reading below is measured for Sligo itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSligo runs about 184 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
MeasuredSligo sits in USDA hardiness zone 6a.
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 Sligo is in
Sligo sits in the Western Allegheny Plateau — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Sligo's own centroid rather than borrowed from Clarion County.
What Grows in Sligo
Every plant below cleared Sligo's own zone 6a and its 184-day season. Each card opens that plant's Pennsylvania profile. How we score.
Is it too late to plant in Sligo?
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 30; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 28 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
Documented around Sligo
Spotted lanternfly documented 2 miles from Sligo, first recorded 2019. What to watch for.
What's on the federal record near Sligo
Closest first, within ~10 miles of Sligo. Listing isn't leaking, and distance isn't exposure.
- LERCHS PLAZA SVC STAUnderground Storage Tanks · 1700 ft
- FAMILY DOLLAR STORE NO 10299Brownfields · 0.6 mi
- SLIGO CITGOUnderground Storage Tanks · 0.7 mi
- CLARION CJP VORTACUnderground Storage Tanks · 0.7 mi
- ARTHUR E FOREST FARMUnderground Storage Tanks · 0.7 mi
- GOULD ENERGY LAB DIV CLARIONUnderground Storage Tanks · 0.7 mi
- STAHLMAN PLUMBING & HEATINGUnderground Storage Tanks · 0.7 mi
- SELKER BROSUnderground Storage Tanks · 0.8 mi
- CK WHSEUnderground Storage Tanks · 0.9 mi
- LANTELME SALES & SVCUnderground Storage Tanks · 1.7 mi
- SLIGO 88259Underground Storage Tanks · 2.3 mi
- CR 683 FORMERLY WELLNitrate · 2.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Sligo'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 Sligo.
Total Sites
353
within ~10 miles of Sligo
Risk Level
Elevated
Highest-severity
11 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Sligo
Severity Distribution
within ~10 miles of Sligo
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Sligo, Nitrate runs higher than the national average — 174 sites within ~10 miles of Sligo. That's not a problem with your land — it's information about it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Sligo
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 Sligo average
Your land is one point inside Sligo
Everything above resolves to Sligo as a whole — one PHZM band and one 28°F frost record, read across 900 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 Sligo Average
Sligo Average
- ●USDA Zones 6a, averaged across Sligo
- ●One soil character for all of Sligo
- ●Frost dates read at Sligo's scale: Apr 27 to Oct 28
YOUR Parcel
- ✓Your exact zone, not Sligo's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Sligo
Pull a site-specific report for your exact address in Sligo, Pennsylvania — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Sligo averages can't show:
We read public map data around Sligo — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Sligo average
How we know this about Sligo
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 Sligo’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 Sligo
When does frost risk typically end in Sligo?
The last hard freeze (28°F) in Sligo typically lands around Apr 27, 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 18.
When is the first frost in Sligo?
The first hard freeze (28°F) in Sligo typically arrives around Oct 28, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 14, so the watching starts about Sep 28 — about 184 days after the spring freeze cleared.
How long is the growing season in Sligo?
Measured between 28°F hard freezes, Sligo sees about 184 frost-free days — roughly Apr 27 through Oct 28, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 18 to Oct 14, about 149 days.
Is the soil safe to grow vegetables in Sligo?
The federal record around Sligo is a meaningful one — 353 documented sites, mostly Nitrate entries (174), the nearest Underground Storage Tanks record about 0.3 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 Sligo?
From about Sep 28 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 28 (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 28. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Sligo's scale — its 6a band and its 184-day season. Your yard writes its own version of Sligo'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 Sligo’s own scale
7 of the readings below were taken at Sligo's own scale — its own ~184-day season between 28°F freezes, the 900 acres it covers and 353 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Sligo's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Sligo's own 28°F hard-freeze dates, about Apr 27 and Oct 28 and the ~184-day span between themNOAA 1991–2020 Climate Normals
- 353 documented contamination sites on the federal record near Sligo, the closest Underground Storage Tanks record about 0.3 miles out from the town centreFederal environmental registers
- Sligo's boundary and the 900 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~184-day seasonGrowable Ground crop-matching engine
- The ecoregion at Sligo's own centroid, the Western Allegheny PlateauUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Sligolydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Sligo's 900 acres read through its county's SSURGO summaryfrom Clarion County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Clarion 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 Clarion County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Sligo's 900 acreswhy one lot differs from the next →
- Which side of Sligo you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 900 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.3 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 Sligo-wide figureread your own land →
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