Williams County, in Ohio, sits in USDA hardiness zone 6a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Reliable performers under these conditions include cabbage, hazelnut, lavender, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Williams County holds more than one microclimate.
Soils and elevations shift across Williams 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 Williams County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Williams County — the short answer
Williams County, Ohio: USDA zone 6a, about 195 days between hard freezes, across 269K acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 15
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 27
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~195
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 269K 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 Williams County's average, not your lot's — a low corner or a tree line moves it. Against Williams County's 195-day season, see what your own ground reads.
Heat in Williams County
Across a year, Williams County accumulates about 2,669 growing degree days above 50°F, about 253 fewer than the middle Ohio county — ahead of 8 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 Williams County
Across Williams County, the ground is predominantly Alfisols, where Blount, Glynwood, and Pewamo are the most extensive named soil series. The soil is generally somewhat poorly drained with a loam surface. Topsoil pH runs about 6.2–6.5, slightly acidic. Rainfall drains through hydrologic group D soils.
Soil order
Alfisols
Drainage
Somewhat poorly drained
Prime farmland
12%
Hydric soils
27%
Soil still varies lot by lot — soil types explained.
How the ground varies across Williams County
The USDA soil survey maps 51% of Williams County as somewhat poorly drained — but another 48% drains differently: 25% very poorly drained, 17% moderately well drained.
Blount is the most extensive named soil at 31% of mapped acres, then Glynwood (12%) and Pewamo (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 Williams County
Each reading below is measured for Williams 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 Williams County are somewhat poorly drained, in hydrologic group D — ground that sheds water slowly.
Beds can stay saturated for days after heavy rain, and the roots of most vegetables, berries, and fruit trees suffocate or rot in soil that never drains.
Raised beds or mounded rows lift roots above the wet zone; choose water-tolerant crops for the lowest spots.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Williams County runs about pH 6.2–6.5, 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
MeasuredWilliams County runs about 195 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
MeasuredWilliams County sits in USDA hardiness zone 6a.
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 Williams County is in
Williams County spans 2 EPA Level III ecoregions — Eastern Corn Belt Plains (79%) and Huron/Erie Lake Plains (21%). 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 Williams County
We scored all 1,086 plants against Williams County's own USDA zone 6a and its own 195-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 Williams County?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Mar 18; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 15 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 27 — long-season crops need about 90 days of runway, quick greens only 30. As the window narrows, the plantings just get faster — fall brassicas, then greens, then garlic to finish.
Documented around Williams County
Survey cells within 31 miles of Williams County checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 45 miles off. What to watch for.
What gets applied to farmland in Williams County
USGS estimates 79,748 lb of Glyphosate on Williams County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (19,932 lb) and Atrazine (16,943 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 Williams County — and how to grow with it.
We checked the federal record across Williams County — 319 documented sites across 7 of the 9 source types we track.
The most significant on record: 2 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 Williams 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 Williams County
Closest first, across Williams County. Listing isn't leaking, and distance isn't exposure.
- MONTPELIER EXEMPTED VILLAGE SCHOOLSBrownfields · 0.8 mi
- MOORE INDUSTRIESBrownfields · 1.0 mi
- POWERS & SONSUnderground Storage Tanks · 1.3 mi
- MARTIN SPROCKET & GEAR INCBrownfields · 1.4 mi
- HAUSE MACHINES INCBrownfields · 1.4 mi
- SPX CORP INC ROBINAIR DIVToxics Release Inventory · 1.5 mi
- MILLER'S GASUnderground Storage Tanks · 1.5 mi
- JEFFERSON TWP MAINT BLDGUnderground Storage Tanks · 1.5 mi
- MONTPELIER WASH-N-FILLUnderground Storage Tanks · 1.5 mi
- MILLER BODY SHOPBrownfields · 1.5 mi
- WINZELER STAMPING COToxics Release Inventory · 1.5 mi
- CERTIFIED OIL STATION 315Brownfields · 1.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Williams 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 Williams County.
Total Sites
319
across Williams County
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
across Williams County
Severity Distribution
across Williams County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Williams County, two things run higher than the national average across Williams County — Toxics Release Inventory (43 sites) and PFAS (3 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around 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.
Check your specific parcel in Williams 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 Williams County average
Your land is one point inside Williams County
Everything above resolves to Williams County as a whole — one PHZM band and one county frost record, read across 269K 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 Williams County Average
Williams County Average
- ●USDA Zones 6a, averaged across Williams County
- ●One soil character for all of Williams County
- ●Frost dates read at Williams County's scale: Apr 15 to Oct 27
YOUR Parcel
- ✓Your exact zone, not Williams County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Williams County
Pull a site-specific report for your exact address in Williams County, Ohio — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Williams County averages can't show:
We read public map data around Williams County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Williams County average
How we know this about Williams 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 Williams County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Williams County
When does frost risk typically end in Williams County?
The last hard freeze (28°F) in Williams County typically lands around Apr 15, 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 6.
How long is the growing season in Williams County?
Measured between 28°F hard freezes, Williams County sees about 195 frost-free days — roughly Apr 15 through Oct 27, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 6 to Oct 13, about 160 days.
Is the soil safe to grow vegetables in Williams County?
The federal record around Williams County is a meaningful one — 319 documented sites, mostly Underground Storage Tanks entries (121), the nearest Brownfields record about 0.8 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 Williams County's scale — its 6a band and its 195-day season. Your yard writes its own version of Williams 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 Williams County’s own scale
8 of the readings below were taken at Williams County's own scale — its own ~195-day span between 28°F freezes, the 3 most extensive soil series mapped here and 319 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Williams County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Williams County's own 28°F hard-freeze dates and its ~195-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Williams CountyUSDA NRCS SSURGO
- 319 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Brownfields record about 0.8 miles outFederal environmental registers
- Williams County's boundary and the 269,222 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~195-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Williams County spans, Eastern Corn Belt Plains the largestUS EPA Level III Ecoregions
- Which agricultural compounds go onto Williams 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 Williams County — the ~195 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 Williams County's 269,222 acreswhy one lot differs from the next →
- Which of those 319 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 Williams Countyread your own land →