Hamilton County, in Ohio, sits in USDA hardiness zone 6b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Well-matched crops include cabbage, hazelnut, lavender, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Hamilton County lies within the Ohio River Valley — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Hamilton County holds more than one microclimate.
Soils and elevations shift across Hamilton 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 Hamilton County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Hamilton County — the short answer
Hamilton County, Ohio: USDA zone 6b, about 225 days between hard freezes, across 259K acres.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 31
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 11
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~225
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 259K 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 Hamilton County's average, not your lot's — a low corner or a tree line moves it. Against Hamilton County's 225-day season, see what your own ground reads.
Heat in Hamilton County
Across a year, Hamilton County accumulates about 3,586 growing degree days above 50°F, about 664 more than the middle Ohio county — ahead of every other Ohio county. 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 Hamilton County
Across Hamilton County, the ground is predominantly Alfisols, where Eden, Switzerland, and Rossmoyne are the most extensive named soil series. The soil is generally well drained with a silty clay loam surface. Topsoil pH runs about 5.5–6.8, slightly acidic. Rainfall drains through hydrologic group D soils.
Soil order
Alfisols
Drainage
Well drained
Prime farmland
7%
Hydric soils
0%
Soil still varies lot by lot — soil types explained.
How the ground varies across Hamilton County
The USDA soil survey maps 35% of Hamilton County as well drained — but another 5% drains differently: 4% moderately well drained, 1% somewhat poorly drained.
Eden is the most extensive named soil at 27% of mapped acres, then Switzerland (4%) and Rossmoyne (3%).
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 Hamilton County
Each reading below is measured for Hamilton 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 Hamilton County are well drained, in hydrologic group D — 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 Hamilton County runs about pH 5.5–6.8, 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
MeasuredHamilton County runs about 225 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
MeasuredHamilton 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 Hamilton County is in
Hamilton County spans 2 EPA Level III ecoregions — Eastern Corn Belt Plains (52%) and Interior Plateau (48%). Which one your land falls in changes what grows wild there and how the ground behaves, and a county-wide answer cannot tell you which.
What Grows in Hamilton County
We scored all 1,086 plants against Hamilton County's own USDA zone 6b and its own 225-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 Hamilton 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 3; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 31 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 11 — long-season crops need about 90 days of runway, quick greens only 30. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.
Documented around Hamilton County
Spotted lanternfly documented 2 miles from Hamilton County, first recorded 2023. What to watch for.
- Japanese beetle17 documented records
- monarch butterfly147 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Hamilton County
USGS estimates 8,464 lb of Glyphosate on Hamilton County farmland in 2019, its largest by weight, ahead of Acetochlor (7,475 lb) and Metolachlor & Metolachlor-s (6,720 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 Hamilton County — and how to grow with it.
We checked the federal record across Hamilton County — 3,081 documented sites across 7 of the 9 source types we track.
The most significant on record: 51 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Hamilton County carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Hamilton County
Closest first, across Hamilton County. Listing isn't leaking, and distance isn't exposure.
- SPRINGDALE CLEANERSBrownfields · 500 ft
- FAMILY DOLLAR #1792Brownfields · 600 ft
- BP OIL CO. #09001Underground Storage Tanks · 650 ft
- MAGGIE RIEGERUnderground Storage Tanks · 1200 ft
- PHOENIX INT'L LIFE SCIENCES, INCUnderground Storage Tanks · 1300 ft
- CITY OF CINCINNATIUnderground Storage Tanks · 1600 ft
- PEARCE'S AUTO CAREUnderground Storage Tanks · 1700 ft
- FIRE CO. #51Underground Storage Tanks · 1900 ft
- AIKEN HIGH SCHOOLUnderground Storage Tanks · 2100 ft
- ORPHAN TANKSUnderground Storage Tanks · 0.5 mi
- DONALD H. MERGARDUnderground Storage Tanks · 0.6 mi
- TWIN TOWERSUnderground Storage Tanks · 0.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Hamilton 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 Hamilton County.
Sources Checked
across Hamilton County
Severity Distribution
across Hamilton County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Hamilton County, two things run higher than the national average across Hamilton County — Toxics Release Inventory (313 sites) and Superfund (51 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.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Hamilton 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 Hamilton County average
Your land is one point inside Hamilton County
Everything above resolves to Hamilton County as a whole — one PHZM band and one county frost record, read across 259K 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 Hamilton County Average
Hamilton County Average
- ●USDA Zones 6b, averaged across Hamilton County
- ●One soil character for all of Hamilton County
- ●Frost dates read at Hamilton County's scale: Mar 31 to Nov 11
YOUR Parcel
- ✓Your exact zone, not Hamilton County's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Hamilton County
Pull a site-specific report for your exact address in Hamilton County, Ohio — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Hamilton County averages can't show:
We read public map data around Hamilton County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Hamilton County average
How we know this about Hamilton 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 Hamilton County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Hamilton County
When does frost risk typically end in Hamilton County?
The last hard freeze (28°F) in Hamilton County typically lands around Mar 31, 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 21.
How long is the growing season in Hamilton County?
Measured between 28°F hard freezes, Hamilton County sees about 225 frost-free days — roughly Mar 31 through Nov 11, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 21 to Oct 28, about 190 days.
Is the soil safe to grow vegetables in Hamilton County?
The federal record around Hamilton County runs heavier than most — 3,081 documented sites, mostly Underground Storage Tanks entries (1,661), the nearest Brownfields record under a tenth of a mile out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
Everything above is measured at Hamilton County's scale — its 6b band and its 225-day season. Your yard writes its own version of Hamilton 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 Hamilton County’s own scale
9 of the readings below were taken at Hamilton County's own scale — its own ~225-day span between 28°F freezes, the 3 most extensive soil series mapped here and 3,081 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Hamilton County's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Hamilton County's own 28°F hard-freeze dates and its ~225-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Hamilton CountyUSDA NRCS SSURGO
- 3,081 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Brownfields record under a tenth of a mile outFederal environmental registers
- Hamilton County's boundary and the 259,490 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~225-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Hamilton County spans, Eastern Corn Belt Plains the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Hamilton County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Hamilton 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 Hamilton County — the ~225 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 Hamilton County's 259,490 acreswhy one lot differs from the next →
- Which of those 3,081 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 Hamilton Countyread your own land →