Warren County, in Ohio, sits in USDA hardiness zone 6b — a zone band wide enough that plant choice, not possibility, is the interesting question.
On paper, cabbage, hazelnut, lavender, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Warren County holds more than one microclimate.
Soils and elevations shift across Warren 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 Warren County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Warren County — the short answer
Warren County, Ohio: USDA zone 6b, about 216 days between hard freezes, across 257K acres.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 2
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 4
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~216
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 257K 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 Warren County's average, not your lot's — a low corner or a tree line moves it. Against Warren County's 216-day season, see what your own ground reads.
Heat in Warren County
Across a year, Warren County accumulates about 3,287 growing degree days above 50°F, about 365 more than the middle Ohio county — ahead of 78 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 Warren County
Across Warren County, the ground is predominantly Alfisols, where Miamian, Russell, and Clermont are the most extensive named soil series. The soil is generally well drained with a silt loam surface. Topsoil pH runs about 5.9–6.7, slightly acidic. Rainfall drains through hydrologic group C soils.
Soil order
Alfisols
Drainage
Well drained
Prime farmland
34%
Hydric soils
14%
Soil still varies lot by lot — soil types explained.
How the ground varies across Warren County
The USDA soil survey maps 46% of Warren County as well drained — but another 48% drains differently: 23% moderately well drained, 12% somewhat poorly drained.
Miamian is the most extensive named soil at 10% of mapped acres, then Russell (9%) and Clermont (8%).
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 Warren County
Each reading below is measured for Warren 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 Warren 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 Warren County runs about pH 5.9–6.7, close to neutral.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Season length
MeasuredWarren County runs about 216 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
MeasuredWarren 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 Warren County is in
Warren County sits in the Eastern Corn Belt Plains — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Warren County
We scored all 1,086 plants against Warren County's own USDA zone 6b and its own 216-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 Warren 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 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 4 — 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 Warren County
Spotted lanternfly documented 28 miles from Warren County, first recorded 2023. What to watch for.
- Japanese beetle4 documented records
- monarch butterfly1,009 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Warren County
USGS estimates 69,014 lb of Glyphosate on Warren County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (48,991 lb) and Metolachlor (33,547 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 Warren County — and how to grow with it.
We checked the federal record across Warren County — 634 documented sites across 6 of the 9 source types we track.
The most significant on record: 9 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 Warren 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 Warren County
Closest first, across Warren County. Listing isn't leaking, and distance isn't exposure.
- 727 EAST MAIN LEBANON LLCUnderground Storage Tanks · 1.3 mi
- BP OIL COBrownfields · 1.3 mi
- FAMILY DOLLAR #3228Brownfields · 1.3 mi
- SPEEDWAY SUPERAMERICA LLC NO 5105Brownfields · 1.3 mi
- ALL SEASONSUnderground Storage Tanks · 1.3 mi
- SPEEDWAY #5105Underground Storage Tanks · 1.3 mi
- PILOT TRAVEL CENTER #552Underground Storage Tanks · 1.5 mi
- INTERSTATE FOOD MART/VALEROUnderground Storage Tanks · 1.5 mi
- I-71 PIT STOPUnderground Storage Tanks · 1.5 mi
- EAST END CARRY OUTUnderground Storage Tanks · 1.5 mi
- LEBANON FARM IMPLEMENTS INCUnderground Storage Tanks · 1.6 mi
- CLARK OIL SERVICE STATION #8070Underground Storage Tanks · 1.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Warren 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 Warren County.
Sources Checked
across Warren County
Severity Distribution
across Warren County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Warren County, two things run higher than the national average across Warren County — PFAS (9 sites) and Toxics Release Inventory (65 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.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Warren 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 Warren County average
Your land is one point inside Warren County
Everything above resolves to Warren County as a whole — one PHZM band and one county frost record, read across 257K 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 Warren County Average
Warren County Average
- ●USDA Zones 6b, averaged across Warren County
- ●One soil character for all of Warren County
- ●Frost dates read at Warren County's scale: Apr 2 to Nov 4
YOUR Parcel
- ✓Your exact zone, not Warren County's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Warren County
Pull a site-specific report for your exact address in Warren County, Ohio — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Warren County averages can't show:
We read public map data around Warren County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Warren County average
How we know this about Warren 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 Warren County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Warren County
When does frost risk typically end in Warren County?
The last hard freeze (28°F) in Warren County 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.
How long is the growing season in Warren County?
Measured between 28°F hard freezes, Warren County sees about 216 frost-free days — roughly Apr 2 through Nov 4, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 23 to Oct 21, about 181 days.
Is the soil safe to grow vegetables in Warren County?
The federal record around Warren County is a meaningful one — 634 documented sites, mostly Underground Storage Tanks entries (307), the nearest Underground Storage Tanks record about 1.3 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.
Everything above is measured at Warren County's scale — its 6b band and its 216-day season. Your yard writes its own version of Warren 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 Warren County’s own scale
9 of the readings below were taken at Warren County's own scale — its own ~216-day span between 28°F freezes, the 3 most extensive soil series mapped here and 634 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Warren County's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Warren County's own 28°F hard-freeze dates and its ~216-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Warren CountyUSDA NRCS SSURGO
- 634 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 1.3 miles outFederal environmental registers
- Warren County's boundary and the 256,905 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~216-day seasonGrowable Ground crop-matching engine
- Warren County sitting wholly inside the Eastern Corn Belt PlainsUS EPA Level III Ecoregions
- Open occurrence records documented in Warren County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Warren 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 Warren County — the ~216 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 Warren County's 256,905 acreswhy one lot differs from the next →
- Which of those 634 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 Warren Countyread your own land →