Defiance County, in Ohio, sits in USDA hardiness zone 6a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Among the crops suited to this profile: cabbage, hazelnut, lavender, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Defiance County holds more than one microclimate.
Soils and elevations shift across Defiance 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 Defiance County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Defiance County — the short answer
Defiance County, Ohio: USDA zone 6a, about 202 days between hard freezes, across 263K acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 11
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 30
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~202
- 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 Defiance County's average, not your lot's — a low corner or a tree line moves it. Against Defiance County's 202-day season, see what your own ground reads.
Heat in Defiance County
Across a year, Defiance County accumulates about 2,825 growing degree days above 50°F, about 97 fewer than the middle Ohio county — ahead of 23 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 Defiance County
Across Defiance County, the ground is predominantly Alfisols, where Latty, Hoytville, and Paulding are the most extensive named soil series. The soil is generally very poorly drained with a loam surface. Topsoil pH runs about 6.2–6.7, slightly acidic. Rainfall drains through hydrologic group D soils.
Soil order
Alfisols
Drainage
Very poorly drained
Prime farmland
7%
Hydric soils
57%
Soil still varies lot by lot — soil types explained.
How the ground varies across Defiance County
The USDA soil survey maps 53% of Defiance County as very poorly drained — but another 46% drains differently: 32% somewhat poorly drained, 8% moderately well drained.
Latty is the most extensive named soil at 14% of mapped acres, then Hoytville (14%) and Paulding (13%).
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 Defiance County
Each reading below is measured for Defiance 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 Defiance County are very 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 Defiance County runs about pH 6.2–6.7, 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
MeasuredDefiance County runs about 202 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
MeasuredDefiance 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 Defiance County is in
Defiance County spans 2 EPA Level III ecoregions — Huron/Erie Lake Plains (84%) and Eastern Corn Belt Plains (16%). 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 Defiance County
We scored all 1,086 plants against Defiance County's own USDA zone 6a and its own 202-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 Defiance 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 14; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 11 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 30 — long-season crops need about 90 days of runway, quick greens only 30. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
Documented around Defiance County
Survey cells within 31 miles of Defiance County checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 40 miles off. What to watch for.
- monarch butterfly1 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Defiance County
USGS estimates 138,621 lb of Glyphosate on Defiance County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (30,446 lb) and Dicamba (19,890 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 Defiance County — and how to grow with it.
We checked the federal record across Defiance County — 220 documented sites across 6 of the 9 source types we track.
The most significant on record: 3 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 Defiance 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 Defiance County
Closest first, across Defiance County. Listing isn't leaking, and distance isn't exposure.
- ODNR OXBOW FISH UNITUnderground Storage Tanks · 3.0 mi
- DEFIANCE COUNTY AIRPORTUnderground Storage Tanks · 3.0 mi
- DEFIANCE COUNTY HIGHWAY GARAGEUnderground Storage Tanks · 3.0 mi
- HICKSVILLE GRAIN COMPANYBrownfields · 3.1 mi
- RED LINE EQUIPMENTBrownfields · 3.7 mi
- ARCHBOLD EQUIPMENT COBrownfields · 3.7 mi
- QUALITY MACHINING & MFG INCBrownfields · 3.8 mi
- VILLAGE FOODUnderground Storage Tanks · 3.8 mi
- SHERWOOD MARATHONUnderground Storage Tanks · 3.9 mi
- VACANT BUILDINGUnderground Storage Tanks · 4.0 mi
- MID CITY PRODUCTS, INC.Underground Storage Tanks · 4.0 mi
- FRIENDS & NEIGHBORS IN HOME HEALUnderground Storage Tanks · 4.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Defiance 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 Defiance County.
Total Sites
220
across Defiance County
Risk Level
Elevated
Highest-severity
3 Superfund sites (none NPL-listed)
Sources Checked
across Defiance County
Severity Distribution
across Defiance County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Defiance County, two things run higher than the national average across Defiance County — Toxics Release Inventory (21 sites) and Superfund (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.
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 Defiance 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 Defiance County average
Your land is one point inside Defiance County
Everything above resolves to Defiance 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 Defiance County Average
Defiance County Average
- ●USDA Zones 6a, averaged across Defiance County
- ●One soil character for all of Defiance County
- ●Frost dates read at Defiance County's scale: Apr 11 to Oct 30
YOUR Parcel
- ✓Your exact zone, not Defiance County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Defiance County
Pull a site-specific report for your exact address in Defiance County, Ohio — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Defiance County averages can't show:
We read public map data around Defiance County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Defiance County average
How we know this about Defiance 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 Defiance County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Defiance County
When does frost risk typically end in Defiance County?
The last hard freeze (28°F) in Defiance County typically lands around Apr 11, 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 2.
How long is the growing season in Defiance County?
Measured between 28°F hard freezes, Defiance County sees about 202 frost-free days — roughly Apr 11 through Oct 30, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 2 to Oct 16, about 167 days.
Is the soil safe to grow vegetables in Defiance County?
The federal record around Defiance County is a meaningful one — 220 documented sites, mostly Underground Storage Tanks entries (114), the nearest Underground Storage Tanks record about 3.0 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 Defiance County's scale — its 6a band and its 202-day season. Your yard writes its own version of Defiance 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 Defiance County’s own scale
9 of the readings below were taken at Defiance County's own scale — its own ~202-day span between 28°F freezes, the 3 most extensive soil series mapped here and 220 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Defiance County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Defiance County's own 28°F hard-freeze dates and its ~202-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Defiance CountyUSDA NRCS SSURGO
- 220 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 3.0 miles outFederal environmental registers
- Defiance County's boundary and the 263,321 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~202-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Defiance County spans, Huron/Erie Lake Plains the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Defiance County for a tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Defiance 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 Defiance County — the ~202 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 Defiance County's 263,321 acreswhy one lot differs from the next →
- Which of those 220 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 Defiance Countyread your own land →