The Ohio River Valley spans USDA hardiness zones 6a-7a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
The warm river ribbon threading three states. The Ohio River's moderating flow gives its frontage counties a longer, milder season (zones 6a-7a, ~221 frost-free days) than the colder uplands just inland — a distinct corridor, not the surrounding hill country. It is also historic American wine country: the Ohio River Valley is a federally recognized winegrowing appellation (TTB AVA, 27 CFR §9.78), and its silty bottomland terraces still favor grapes and river-valley vegetables. The conditions favor tomato, sweet corn, zucchini, and pawpaw, among others — though every individual site edits that list with its own soil, sun, and drainage.
Your yard isn't all of the Ohio River Valley.
The Ohio River Valley spans USDA zones 6a-7a, but your parcel sits in exactly one — and slope, tree cover, and low spots nudge it further. 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 Ohio River Valley — soil, climate, flood, and parcel records. How we handle your address.
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The Ohio River Valley — the short answer
The Ohio River Valley: USDA zones 6a-7a, 182–245 frost-free days depending where in it you stand, across 3 states.
- USDA zones
- 6a-7a
- USDA PHZM 2023, aggregated over the footprint
- Shortest season here
- 182 days
- NOAA Regional Climate Centers ACIS, 1991-2020 — Columbiana County
- Counties
- 48
- US Census TIGER/Line 2025
- Region type
- County cluster
- Growable Ground growing-region registry
Region boundary: Growable Ground growing-region registry — curated county clusters, EPA Level III ecoregions, and town clusters drawn finer than any county. The season figure is this region's own record, measured across its 48 member counties, not a state or national average.
Hardiness Zone Range
The Ohio River Valley is not one growing season
One answer for the Ohio River Valley averages 48 counties whose growing seasons are 63 days apart — from 182 frost-free days in Columbiana County to 245 in Jefferson County. That is the same region, measured the same way, in the same years. Which end of it your land sits nearer decides what finishes before the first hard freeze.
The middle half of 48 counties runs 215–229 days, with a median of 221 days — a 63-day span end to end.
Measured across 48 member counties, each carrying its own 28°F normal. NOAA Regional Climate Centers ACIS, 1991-2020. A member with no own record is absent from the range rather than counted as zero — nothing here is interpolated to the region. Your own site sits somewhere inside this range; a parcel report resolves where.
Where the line runs inside the Ohio River Valley
The middle half of the Ohio River Valley runs 215–229 frost-free days, and 23 of its 48 counties sit outside that — 12 on the short side, 11 on the long. A regional planting date describes the middle well and the ends poorly, which is worth knowing before you follow one.
Under 215 frost-free days
12 counties
- Columbiana County · 182 days
- Greenup County · 195 days
- Meigs County · 201 days
3 of 12 shown
The end of the region that sets the planting calendar — start seed indoors here and the season stretches to meet the crop.
215–229 frost-free days
25 counties
0 of 25 shown
The middle half of the region, and the part a single regional season describes well.
Over 229 frost-free days
11 counties
- Jefferson County · 245 days
- Ballard County · 240 days
- Livingston County · 239 days
3 of 11 shown
Long enough for a second succession of a quick crop after the first comes out.
Each county is placed by its OWN 28°F frost-free normal (NOAA Regional Climate Centers ACIS, 1991-2020), the same figure its own guide page publishes. Elevation, slope and cold-air drainage move a site within its county as well — which is the part only your address resolves.
What Grows in the Ohio River Valley
All 3 of the plants below that publish a season requirement clear even Columbiana County’s 182 frost-free days — so on season alone, this grid works at both ends of the region. The 63-day spread still decides how far past this list you can push, and how early you can start.
Plants matched to the Ohio River Valley's USDA zones 6a-7a, ordered by how much hardiness margin each has across the region — the ones with room to spare at both ends of this band lead. Each links to its full growing profile.
Native Plants of the Ohio River Valley
Plants the USDA PLANTS Database documents as native and present in all 3 states this region crosses, kept only where the published hardiness range meets the Ohio River Valley’s USDA zones 6a-7a — closest range match first. Presence is recorded by state, so a plant can be documented across the state and still be scarce in your corner of the region.
The ground across the Ohio River Valley
The USDA soil survey maps this ground county by county. These are those records weighted by land area across 48 member counties — this region’s own profile, not a state figure.
The ground is predominantly Alfisols, at 62% of mapped acres, followed by Inceptisols (15%), Ultisols (13%) and Entisols (7%). Six soil orders appear somewhere inside the footprint, which is the honest reason a regional soil answer only goes so far. The most extensive named soils are Eden, Gilpin, and Upshur.
59% of those acres are well drained, and another 21% moderately well drained, 7% somewhat poorly drained. Topsoil pH runs 4.5–7.5 between the lowest and the highest county on record. 17% of the footprint is classed prime farmland.
Soil order
Alfisols
Drainage
Well drained
Topsoil pH
4.5–7.5
Hydric soils
5%
Soil changes across a driveway, so which of these your own ground sits on is a parcel question rather than a regional one. Brown County holds the most wetland ground here, at 23% — soil types explained.
USDA NRCS SSURGO via Soil Data Access
What this means for growing in the Ohio River Valley
The soil survey reads this ground county by county, and the readings above are those records summed across the Ohio River Valley. Here is what they mean for a garden here — and the move an experienced grower makes about each one.
Drainage
From county records59% of the mapped acres across the Ohio River Valley are well drained — ground that drains quickly. That is area-weighted across all 48 of its mapped counties.
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
From county recordsTopsoil across the Ohio River Valley runs pH 4.5–7.5 — acidic in 27 of its 48 counties.
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
Safe to Grow Here?
What the federal record shows across the Ohio River Valley — and how to grow with it.
Across the Ohio River Valley's 48 counties the federal record holds 17,277 documented sites, mostly Underground Storage Tanks (10,399), Brownfields (3,767) and Nitrate (1,468). The heaviest single county is Hamilton County, with 3,081.
That is a regional count, not a reading of any one lot — proximity to a documented site is information, not a diagnosis. Open the map outlined to the Ohio River Valley to see which records sit where you actually grow.
Sources Checked
Summed across the 48 counties in the Ohio River Valley
A note from Gnorman
What an experienced grower watches for around here
In and around the Ohio River Valley, two things run higher than the national average across the 48 counties in the Ohio River Valley — Toxics Release Inventory (1,231 sites) and PFAS (144 sites). That's not a problem with your land — it's information about it.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
Your land is one point inside the Ohio River Valley
Everything above resolves to the Ohio River Valley as a whole — a footprint whose own counties record seasons 63 days apart, and hardiness across zones 6a-7a. Your parcel sits at one point in that range, not in the middle of it. 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 region 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 regional average.
Your Lot vs the Ohio River Valley Average
Ohio River Valley Average
- ●USDA Zones 6a-7a, averaged across Ohio River Valley
- ●One soil character for all of Ohio River Valley
- ●State-average frost dates
YOUR Parcel
- ✓Your exact zone, not Ohio River Valley's 6a-7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in the Ohio River Valley
Pull a site-specific report for your exact address in the Ohio River Valley — soil, sun, drainage, frost risk, contamination, and scored plant recommendations.
Three things about your lot that Ohio River Valley averages can't show:
We read public map data around The Ohio River Valley — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Ohio River Valley average
How we know this about the Ohio River Valley
The boundary: a cluster of neighboring counties. Growing regions have no official boundary, so this footprint is our published one, and every figure on this page was measured over the counties inside it rather than borrowed from the state around it.
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, aggregated across the footprint; the growing season from NOAA Regional Climate Centers ACIS 1991–2020 28°F normals, read at each member’s own record; boundaries from US Census TIGER/Line 2025; the contamination record from the federal sources named in that beat above; the soil from the USDA NRCS SSURGO survey, read at each member county’s own record and weighted to this footprint by land area. Where a member carries no record of its own, it is absent from the figure rather than filled in.
Common questions about the Ohio River Valley
What hardiness zone is the Ohio River Valley?
The Ohio River Valley spans USDA hardiness zones 6a-7a, aggregated from the USDA Agricultural Research Service Plant Hardiness Zone Map 2023 across the region's counties. Zones reflect average annual extreme minimum temperatures from 1991–2020 data.
How long is the growing season in the Ohio River Valley?
Measured between 28°F hard freezes, the Ohio River Valley's counties mostly run 215 to 229 frost-free days, median 221 (NOAA Regional Climate Centers ACIS, 1991–2020, over 48 member counties). That 14-day spread is the honest read — no single season describes 48 counties, and each county guide below carries its own.
When does frost risk end in the Ohio River Valley?
Across the Ohio River Valley, the middle half of member counties see their last 28°F hard freeze between Mar 26 and Apr 4 (median Apr 1), and their first fall freeze between Nov 5 and Nov 10. Those are hard freezes, not the last light frost: tender transplants wait for about Apr 22, and elevation decides which end of a 9-day spread you garden in.
What grows well in the Ohio River Valley?
The Ohio River Valley's conditions suit plants such as Tomato, Sweet Corn, Zucchini, Pawpaw, Peony, Apple. What actually thrives on any one site still turns on its specific soil, sun, and drainage — we score each plant against the real conditions at your address.
How is the Ohio River Valley defined?
The Ohio River Valley is defined here as a curated cluster of 48 neighboring counties that share a growing character. Growing regions have no official boundary, so this footprint is our published one — every county in it is named on this page.
Which states does the Ohio River Valley cover?
The Ohio River Valley spans Indiana, Kentucky, and Ohio. Each state's full growing guide is linked on this page.
What other growing regions cover the same states?
Appalachia, Southern Indiana & the Ohio River Valley, Pennyroyal / Pennyrile (South-Central Kentucky Karst Plateau), Kentucky Bluegrass, Cumberland Plateau, and Jackson Purchase (Far Western Kentucky) share at least one state with the Ohio River Valley. Growing regions overlap and interlock — a single address can sit inside more than one, which is why the precise read is always the parcel, not the region.
What this page reads at the Ohio River Valley’s own scale
6 of the readings below were taken at the Ohio River Valley's own scale — the zone 6a-7a band across its footprint, a median 221-day season across its 48 counties and 17,277 documented federal contamination records across its 48 counties, 3,081 of them in Hamilton County alone; one is borrowed from a wider read, named and linked below.
Measured here
- The USDA hardiness band 6a-7a aggregated across all 48 counties in the footprintUSDA PHZM 2023
- The boundary itself — the 48 counties this region is curated fromGrowable Ground subregion registry
- The growing character that makes this region distinct from the states it crossesGrowable Ground subregion registry
- The 28°F season across the footprint — the middle half of its 48 counties run 215 to 229 frost-free days, median 221NOAA Regional Climate Centers ACIS, 1991-2020
- The federal contamination record over the whole footprint — 17,277 documented federal contamination records across its 48 counties, 3,081 of them in Hamilton County aloneEPA, USGS and USDA federal site records
- The soil order mix across the footprint — 62% Alfisols, topsoil pH 4.5–7.5, area-weighted across its 48 mapped countiesUSDA NRCS SSURGO
Inherited from a wider read
- The candidate plant list — all 3 member states' curated sets, merged and filtered to zones 6a-7afrom Indiana, Kentucky and Ohio
What this page can’t tell you
- Which end of the 14-day range your ground sits at — 215 days at one extreme, 229 at the other, decided mostly by elevationfrost dates explained →
- Which of those soils your own ground sits on — the survey maps them county-wide, and they change across a drivewaysoil types explained →
- The soil pH, drainage, sun hours, and frost pockets on one specific lotwhy one lot differs from the next →
Explore the Ohio River Valley
State growing guides
Counties in this region
Other growing regions across Indiana, Kentucky, and Ohio
The vast eastern mountain region of steep hollows, thin acidic soils, and short upland seasons — apples, brambles, ramps, and forest crops on hard-won ground. (Union of the core Appalachian ecoregions.)
Southern Indiana's upland hill country reaching south to the Ohio River — the 19-county TTB Indiana Uplands wine region (27 CFR §9.240), spanning USDA zones 6a–7a with roughly 205–225 frost-free days.
South-central Kentucky's Pennyroyal — the Pennyrile — is a Mississippian karst sinkhole plain: a limestone country of sinking creeks and caves where surface water drains straight down instead of pooling. It runs a full USDA zone 7a across all 18 counties with a long 211-238 day frost-free season, distinctly warmer and longer than the cooler Bluegrass to the northeast, and its well-drained cherty limestone soils behave differently from the Bluegrass's rich phosphatic bottomland. This is Kentucky's dark-fired and burley tobacco, corn, soybean, cattle, and hay belt, anchored by the fast-growing Bowling Green and Hopkinsville metros — none of which a flattened statewide page resolves.
Central Kentucky's rolling phosphate-rich limestone soils — famous pasture and tobacco country that also grows excellent vegetables and tree fruit.
The Cumberland Plateau isn't the broad Appalachian average — it's a sandstone tableland riding roughly 1,500 to 2,000 feet above the valleys on either side, and that elevation sets the growing rules here. Across these 14 Kentucky and Tennessee plateau counties (EPA's Southwestern Appalachians ecoregion, the scientific line for the plateau), the hardiness band tightens to 7a-7b and the frost-free season runs close to 210 days — median last frost in early April, first frost in early November, later to warm in spring and quicker to cool in fall than the limestone valleys below. The plateau's other signature is underfoot: acidic, sandy soils weathered from Pennsylvanian sandstone, lean on natural fertility but a genuine fit for blueberries, blackberries, and other acid-loving crops that struggle in the sweet limestone soils of the Bluegrass to the west. Plan for the cooler nights, feed the lean soil, and grow toward what the tableland does well.
The Jackson Purchase is Kentucky's warmest, longest-season corner — a flat block of Mississippi Embayment loess and Gulf Coastal-Plain alluvium west of the Tennessee River, geologically unlike the limestone-and-shale uplands that define the rest of the state. Its eight counties (Paducah to Murray) run PHZM zones 7a–7b with roughly 235–240 frost-free days — about two to three weeks longer than Kentucky's eastern mountains — and its crop identity is a west-Tennessee row-crop belt (soybeans, corn, winter wheat, and the northern fringe of cotton) that neither the statewide Kentucky page nor the Bluegrass/Appalachia regions can tell. Distinct from its nearest captured sibling, ohio-river-valley: that is a thin generic river ribbon, while the Purchase is a coherent warm alluvial flatland with its own soil and season.