Armstrong County, in 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.
Armstrong County lies within Appalachia — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Armstrong County holds more than one microclimate.
Soils and elevations shift across Armstrong 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 Armstrong County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Armstrong County — the short answer
Armstrong County, Pennsylvania: USDA zone 6b, about 191 days between hard freezes, across 418K acres.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 20
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 28
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~191
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 418K 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 6b is Armstrong County's average, not your lot's — a low corner or a tree line moves it. Against Armstrong County's 191-day season, see what your own ground reads.
Heat in Armstrong County
Across a year, Armstrong County accumulates about 2,557 growing degree days above 50°F, about 10 more than the middle Pennsylvania county — ahead of 36 of Pennsylvania’s 67 counties. 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 Armstrong County
Across Armstrong County, the ground is predominantly Ultisols, where Gilpin, Weikert, and Ernest are the most extensive named soil series. The soil is generally well drained with a channery silt loam surface. Topsoil pH runs about 5.0–5.6, strongly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Ultisols
Drainage
Well drained
Prime farmland
12%
Hydric soils
1%
Soil still varies lot by lot — soil types explained.
How the ground varies across Armstrong County
The USDA soil survey maps 65% of Armstrong County as well drained — but another 33% drains differently: 27% moderately well drained, 4% somewhat poorly drained.
Gilpin is the most extensive named soil at 34% of mapped acres, then Weikert (18%) and Ernest (14%).
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 Armstrong County
Each reading below is measured for Armstrong 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 Armstrong County are well drained, in hydrologic group C — 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 Armstrong County runs about pH 5.0–5.6, 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
MeasuredArmstrong County runs about 191 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
MeasuredArmstrong County 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 Armstrong County is in
Armstrong County sits in the Western Allegheny Plateau — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Armstrong County
We scored all 1,086 plants against Armstrong County's own USDA zone 6b and its own 191-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 Armstrong County?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Mar 23; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 20 (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. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
Documented around Armstrong County
Spotted lanternfly documented 3 miles from Armstrong County, first recorded 2022. What to watch for.
- Japanese beetle5 documented records
- monarch butterfly10 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Armstrong County
USGS estimates 48,951 lb of Glyphosate on Armstrong County farmland in 2019, its largest by weight, ahead of Atrazine (14,357 lb) and Metolachlor & Metolachlor-s (14,202 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 Armstrong County — and how to grow with it.
We checked the federal record across Armstrong County — 424 documented sites across 6 of the 9 source types we track.
The most significant on record: 4 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
There's a meaningful federal record across Armstrong County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Armstrong County
Closest first, across Armstrong County. Listing isn't leaking, and distance isn't exposure.
- BARKERS KITTANNINGUnderground Storage Tanks · 350 ft
- ZAMBOTTI COLLISION & WELDING CENTER INCBrownfields · 800 ft
- E ARMSTRONG CNTY MUNI AUTHPFAS · 2300 ft
- PA-AMERICAN WATER CO-KITTANNIGPFAS · 2300 ft
- ARMSDALE STPBrownfields · 1.1 mi
- KITTANNING ARCBrownfields · 1.3 mi
- AJ MYERS & SONSUnderground Storage Tanks · 1.3 mi
- BENCH RACERSUnderground Storage Tanks · 1.4 mi
- PETERS AUTO BODYBrownfields · 1.4 mi
- KWIK FILL S0047 208Brownfields · 1.4 mi
- SHEETZ 445Underground Storage Tanks · 1.5 mi
- SHEETZ STORE NO 445Brownfields · 1.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Armstrong 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 Armstrong County.
Sources Checked
across Armstrong County
Severity Distribution
across Armstrong County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Armstrong County, two things run higher than the national average across Armstrong County — PFAS (6 sites) and Underground Storage Tanks (262 sites). That's not a problem with your land — it's information about it.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Armstrong 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 Armstrong County average
Your land is one point inside Armstrong County
Everything above resolves to Armstrong County as a whole — one PHZM band and one county frost record, read across 418K 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 Armstrong County Average
Armstrong County Average
- ●USDA Zones 6b, averaged across Armstrong County
- ●One soil character for all of Armstrong County
- ●Frost dates read at Armstrong County's scale: Apr 20 to Oct 28
YOUR Parcel
- ✓Your exact zone, not Armstrong County's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Armstrong County
Pull a site-specific report for your exact address in Armstrong County, Pennsylvania — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Armstrong County averages can't show:
We read public map data around Armstrong County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Armstrong County average
How we know this about Armstrong 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 Armstrong County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Armstrong County
When does frost risk typically end in Armstrong County?
The last hard freeze (28°F) in Armstrong County typically lands around Apr 20, 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 11.
How long is the growing season in Armstrong County?
Measured between 28°F hard freezes, Armstrong County sees about 191 frost-free days — roughly Apr 20 through Oct 28, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 11 to Oct 14, about 156 days.
Is the soil safe to grow vegetables in Armstrong County?
The federal record around Armstrong County is a meaningful one — 424 documented sites, mostly Underground Storage Tanks entries (262), 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.
Everything above is measured at Armstrong County's scale — its 6b band and its 191-day season. Your yard writes its own version of Armstrong 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 Armstrong County’s own scale
9 of the readings below were taken at Armstrong County's own scale — its own ~191-day span between 28°F freezes, the 3 most extensive soil series mapped here and 424 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Armstrong County's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Armstrong County's own 28°F hard-freeze dates and its ~191-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Armstrong CountyUSDA NRCS SSURGO
- 424 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record under a tenth of a mile outFederal environmental registers
- Armstrong County's boundary and the 418,125 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~191-day seasonGrowable Ground crop-matching engine
- Armstrong County sitting wholly inside the Western Allegheny PlateauUS EPA Level III Ecoregions
- Open occurrence records documented in Armstrong County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Armstrong 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 Armstrong County — the ~191 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 Armstrong County's 418,125 acreswhy one lot differs from the next →
- Which of those 424 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 Armstrong Countyread your own land →