Mahoning County, in Ohio, sits in USDA hardiness zone 6a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
The conditions favor cabbage, hazelnut, lavender, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Mahoning County lies within the Northeast Ohio Snow Belt (Erie Drift Plain Uplands) — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Mahoning County holds more than one microclimate.
Soils and elevations shift across Mahoning 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 Mahoning County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Mahoning County — the short answer
Mahoning County, Ohio: USDA zone 6a, about 187 days between hard freezes, across 263K acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 21
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 25
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~187
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 263K 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 6a is Mahoning County's average, not your lot's — a low corner or a tree line moves it. Against Mahoning County's 187-day season, see what your own ground reads.
Heat in Mahoning County
Across a year, Mahoning County accumulates about 2,550 growing degree days above 50°F, about 372 fewer than the middle Ohio county — ahead of 2 of Ohio’s 88 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 Mahoning County
Across Mahoning County, the ground is predominantly Alfisols, where Canfield, Mahoning, and Ellsworth are the most extensive named soil series. The soil is generally moderately well drained with a silt loam surface. Topsoil pH runs about 5.0–6.3, moderately acidic. Rainfall drains through hydrologic group D soils.
Soil order
Alfisols
Drainage
Moderately well drained
Prime farmland
24%
Hydric soils
20%
Soil still varies lot by lot — soil types explained.
How the ground varies across Mahoning County
The USDA soil survey maps 33% of Mahoning County as moderately well drained — but another 63% drains differently: 29% somewhat poorly drained, 16% well drained.
Canfield is the most extensive named soil at 12% of mapped acres, then Mahoning (8%) and Ellsworth (6%).
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 Mahoning County
Each reading below is measured for Mahoning 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 Mahoning County are moderately well drained, in hydrologic group D — roughly the middle of the drainage range.
This is close to the middle most vegetables prefer: it holds enough water to carry a crop between rains without staying waterlogged. The catch is that a wet spring or a low corner can still tip it soggy.
Plant on the site as-is for most crops, but keep the lowest, slowest-draining beds for moisture-tolerant plantings.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Mahoning County runs about pH 5.0–6.3, 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
Wet ground
MeasuredAbout 20% of Mahoning County is mapped as hydric — wetland — soil.
If your lot falls in one of those pockets, a standard in-ground bed will fight waterlogging all season, and roots that need air will struggle.
Check how your own ground drains before you dig; raised beds or moisture-loving plantings turn a wet corner from a problem into a niche.
USDA NRCS SSURGO
Season length
MeasuredMahoning County runs about 187 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
The kind of country Mahoning County is in
Mahoning County sits in the Erie Drift Plain — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Mahoning County
We scored all 1,086 plants against Mahoning County's own USDA zone 6a and its own 187-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 Ohio profile.
Is it too late to plant in Mahoning County?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 24; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 21 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 25 — 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 Mahoning County
Spotted lanternfly documented 4 miles from Mahoning County, first recorded 2023. What to watch for.
- Japanese beetle7 documented records
- monarch butterfly10 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Mahoning County
USGS estimates 21,781 lb of Glyphosate on Mahoning County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (8,230 lb) and Metolachlor-s (7,419 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 Mahoning County — and how to grow with it.
We checked the federal record across Mahoning County — 995 documented sites across 6 of the 9 source types we track.
The most significant on record: 10 Superfund sites (none NPL-listed). 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 Mahoning 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 Mahoning County
Closest first, across Mahoning County. Listing isn't leaking, and distance isn't exposure.
- CANFIELD CITY PWSPFAS · 0 ft
- MAHONING CTY AGRICULTURAL SOCIETUnderground Storage Tanks · 0.6 mi
- OHIO STATE HIGHWAY PATROL POSTUnderground Storage Tanks · 0.6 mi
- P-M PARTNERSHIPUnderground Storage Tanks · 0.8 mi
- R. W. SIDLEY, INC.Underground Storage Tanks · 0.9 mi
- LEEBAW MANUFACTURINGBrownfields · 0.9 mi
- CHUCK'S CLASSIC AUTO BODYBrownfields · 0.9 mi
- ACER STORES INC.Underground Storage Tanks · 0.9 mi
- COURTNEY HARVEY FORDUnderground Storage Tanks · 0.9 mi
- CANFIELD LOCAL SCHOOLSUnderground Storage Tanks · 1.0 mi
- FAIRWAY FORD MERCURYBrownfields · 1.0 mi
- OHIO DEPT OF TRANSPORTATIONBrownfields · 1.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Mahoning 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 Mahoning County.
Total Sites
995
across Mahoning County
Risk Level
Elevated
Highest-severity
10 Superfund sites (none NPL-listed)
Sources Checked
across Mahoning County
Severity Distribution
across Mahoning County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Mahoning County, Toxics Release Inventory runs higher than the national average — 63 sites across Mahoning County. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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 Mahoning 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 Mahoning County average
Your land is one point inside Mahoning County
Everything above resolves to Mahoning County as a whole — one PHZM band and one county frost record, read across 263K 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 Mahoning County Average
Mahoning County Average
- ●USDA Zones 6a, averaged across Mahoning County
- ●One soil character for all of Mahoning County
- ●Frost dates read at Mahoning County's scale: Apr 21 to Oct 25
YOUR Parcel
- ✓Your exact zone, not Mahoning County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Mahoning County
Pull a site-specific report for your exact address in Mahoning County, Ohio — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Mahoning County averages can't show:
We read public map data around Mahoning County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Mahoning County average
How we know this about Mahoning 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 Mahoning County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Mahoning County
When does frost risk typically end in Mahoning County?
The last hard freeze (28°F) in Mahoning County typically lands around Apr 21, 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 12.
How long is the growing season in Mahoning County?
Measured between 28°F hard freezes, Mahoning County sees about 187 frost-free days — roughly Apr 21 through Oct 25, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 12 to Oct 11, about 152 days.
Is the soil safe to grow vegetables in Mahoning County?
The federal record around Mahoning County is a meaningful one — 995 documented sites, mostly Underground Storage Tanks entries (532), the nearest PFAS 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 Mahoning County's scale — its 6a band and its 187-day season. Your yard writes its own version of Mahoning 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 Ohio's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Mahoning County’s own scale
9 of the readings below were taken at Mahoning County's own scale — its own ~187-day span between 28°F freezes, the 3 most extensive soil series mapped here and 995 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Mahoning County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Mahoning County's own 28°F hard-freeze dates and its ~187-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Mahoning CountyUSDA NRCS SSURGO
- 995 documented contamination sites inside the county boundary, distance-sorted from its center — the closest PFAS record under a tenth of a mile outFederal environmental registers
- Mahoning County's boundary and the 263,373 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~187-day seasonGrowable Ground crop-matching engine
- Mahoning County sitting wholly inside the Erie Drift PlainUS EPA Level III Ecoregions
- Open occurrence records documented in Mahoning County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Mahoning County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Ohio grower plans around — written at state scale, so they stay on the state guidefrom Ohio
What this page can’t tell you
- How the season shifts across Mahoning County — the ~187 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 Mahoning County's 263,373 acreswhy one lot differs from the next →
- Which of those 995 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 Mahoning Countyread your own land →