Vermilion County, in Illinois, sits in USDA hardiness zone 6a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
These conditions suit cabbage, hazelnut, lavender, and collard greens — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Vermilion County holds more than one microclimate.
Soils and elevations shift across Vermilion 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 Vermilion County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Vermilion County — the short answer
Vermilion County, Illinois: USDA zone 6a, about 202 days between hard freezes, across 575K acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 7
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 26
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~202
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 575K 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 Vermilion County's average, not your lot's — a low corner or a tree line moves it. Against Vermilion County's 202-day season, see what your own ground reads.
Heat in Vermilion County
Across a year, Vermilion County accumulates about 3,217 growing degree days above 50°F, about 166 fewer than the middle Illinois county — ahead of 35 of Illinois’s 102 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 Vermilion County
Across Vermilion County, the ground is predominantly Mollisols, where Drummer, Ashkum, and Flanagan are the most extensive named soil series. The soil is generally somewhat poorly drained with a silt loam surface. Topsoil pH runs about 6.2–6.8, slightly acidic. Rainfall drains through hydrologic group C/D soils.
Soil order
Mollisols
Drainage
Somewhat poorly drained
Prime farmland
47%
Hydric soils
37%
Soil still varies lot by lot — soil types explained.
How the ground varies across Vermilion County
The USDA soil survey maps 46% of Vermilion County as somewhat poorly drained — but another 53% drains differently: 37% poorly drained, 9% well drained.
Drummer is the most extensive named soil at 17% of mapped acres, then Ashkum (11%) and Flanagan (10%).
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 Vermilion County
Each reading below is measured for Vermilion 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 Vermilion County are somewhat poorly drained, in hydrologic group C/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 Vermilion County runs about pH 6.2–6.8, 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
MeasuredVermilion 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
MeasuredVermilion 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 Vermilion County is in
Vermilion County spans 2 EPA Level III ecoregions — Central Corn Belt Plains (70%) and Interior River Valleys and Hills (30%). 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 Vermilion County
We scored all 1,086 plants against Vermilion 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 Illinois profile.
Is it too late to plant in Vermilion 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 10; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 7 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 26 — 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 Vermilion County
- Japanese beetle1 documented records
- monarch butterfly69 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Vermilion County
USGS estimates 390,789 lb of Glyphosate on Vermilion County farmland in 2019, its largest by weight, ahead of Acetochlor (173,443 lb) and Atrazine (147,228 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 Vermilion County — and how to grow with it.
We checked the federal record across Vermilion County — 556 documented sites across 7 of the 9 source types we track.
The most significant on record: 13 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 Vermilion 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 Vermilion County
Closest first, across Vermilion County. Listing isn't leaking, and distance isn't exposure.
- DYNEGY OPERATING COBrownfields · 0.6 mi
- VERMILION POWER STATIONToxics Release Inventory · 1.3 mi
- Newton Middle SchoolUnderground Storage Tanks · 2.3 mi
- Carlton Harold EUnderground Storage Tanks · 2.7 mi
- Middle Fork S F & W AUnderground Storage Tanks · 2.7 mi
- BILL SMITH AUTO PARTSBrownfields · 4.1 mi
- PEARCE SERVICES LLCBrownfields · 4.1 mi
- Illini FS Danville Fuel 24Underground Storage Tanks · 4.4 mi
- MOHR MFG DBA CRONKHITE INDUSTRIES INCBrownfields · 4.4 mi
- Short Stop GroceryUnderground Storage Tanks · 4.4 mi
- Naval & Marine Corps Reserve CenterUnderground Storage Tanks · 4.6 mi
- Lake Vermilion MarinaUnderground Storage Tanks · 4.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Vermilion 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 Vermilion County.
Sources Checked
across Vermilion County
Severity Distribution
across Vermilion County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Vermilion County, two things run higher than the national average across Vermilion County — Superfund (13 sites) and Toxics Release Inventory (44 sites). That's not a problem with your land — it's information about it.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Vermilion 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 Vermilion County average
Your land is one point inside Vermilion County
Everything above resolves to Vermilion County as a whole — one PHZM band and one county frost record, read across 575K 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 Vermilion County Average
Vermilion County Average
- ●USDA Zones 6a, averaged across Vermilion County
- ●One soil character for all of Vermilion County
- ●Frost dates read at Vermilion County's scale: Apr 7 to Oct 26
YOUR Parcel
- ✓Your exact zone, not Vermilion County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Vermilion County
Pull a site-specific report for your exact address in Vermilion County, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Vermilion County averages can't show:
We read public map data around Vermilion County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Vermilion County average
How we know this about Vermilion 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 Vermilion County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Vermilion County
When does frost risk typically end in Vermilion County?
The last hard freeze (28°F) in Vermilion County typically lands around Apr 7, 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 28.
How long is the growing season in Vermilion County?
Measured between 28°F hard freezes, Vermilion County sees about 202 frost-free days — roughly Apr 7 through Oct 26, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 28 to Oct 12, about 167 days.
Is the soil safe to grow vegetables in Vermilion County?
The federal record around Vermilion County is a meaningful one — 556 documented sites, mostly Underground Storage Tanks entries (348), the nearest Brownfields record about 0.6 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 Vermilion County's scale — its 6a band and its 202-day season. Your yard writes its own version of Vermilion 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 Illinois's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Vermilion County’s own scale
9 of the readings below were taken at Vermilion County's own scale — its own ~202-day span between 28°F freezes, the 3 most extensive soil series mapped here and 556 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Vermilion County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Vermilion 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 Vermilion CountyUSDA NRCS SSURGO
- 556 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Brownfields record about 0.6 miles outFederal environmental registers
- Vermilion County's boundary and the 574,925 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 Vermilion County spans, Central Corn Belt Plains the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Vermilion County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Vermilion County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every Illinois grower plans around — written at state scale, so they stay on the state guidefrom Illinois
What this page can’t tell you
- How the season shifts across Vermilion 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 Vermilion County's 574,925 acreswhy one lot differs from the next →
- Which of those 556 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 Vermilion Countyread your own land →