Champaign County, in Illinois, sits in USDA hardiness zone 6a — a zone band wide enough that plant choice, not possibility, is the interesting question.
Crops well matched to these conditions include cabbage, hazelnut, lavender, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Champaign County holds more than one microclimate.
Soils and elevations shift across Champaign 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 Champaign County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Champaign County — the short answer
Champaign County, Illinois: USDA zone 6a, about 209 days between hard freezes, across 638K acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 5
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 31
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~209
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 638K 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 Champaign County's average, not your lot's — a low corner or a tree line moves it. Against Champaign County's 209-day season, see what your own ground reads.
Heat in Champaign County
Across a year, Champaign County accumulates about 3,237 growing degree days above 50°F, about 146 fewer than the middle Illinois county — ahead of 39 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 Champaign County
Across Champaign County, the ground is predominantly Mollisols, where Drummer, Flanagan, and Ashkum are the most extensive named soil series. The soil is generally poorly drained with a silty clay loam surface. Topsoil pH runs about 6.2–6.7, slightly acidic. Rainfall drains through hydrologic group B/D soils.
Soil order
Mollisols
Drainage
Poorly drained
Prime farmland
45%
Hydric soils
50%
Soil still varies lot by lot — soil types explained.
How the ground varies across Champaign County
The USDA soil survey maps 49% of Champaign County as poorly drained — but another 50% drains differently: 32% somewhat poorly drained, 12% moderately well drained.
Drummer is the most extensive named soil at 40% of mapped acres, then Flanagan (16%) and Ashkum (5%).
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 Champaign County
Each reading below is measured for Champaign 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 Champaign County are poorly drained, in hydrologic group B/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 Champaign 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
MeasuredChampaign County runs about 209 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
MeasuredChampaign 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 Champaign County is in
Champaign County sits in the Central Corn Belt Plains — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Champaign County
We scored all 1,086 plants against Champaign County's own USDA zone 6a and its own 209-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 Champaign 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 8; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 5 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 31 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
Documented around Champaign County
- Japanese beetle52 documented records
- monarch butterfly241 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Champaign County
USGS estimates 474,672 lb of Glyphosate on Champaign County farmland in 2019, its largest by weight, ahead of Acetochlor (215,965 lb) and Atrazine (184,483 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 Champaign County — and how to grow with it.
We checked the federal record across Champaign County — 820 documented sites across 7 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 Champaign 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 Champaign County
Closest first, across Champaign County. Listing isn't leaking, and distance isn't exposure.
- FRASCA INTERNATIONALBrownfields · 1100 ft
- CALIBER COLLISION CENTER URBANA 2415Brownfields · 1400 ft
- FARM AND FLEET-URBANABrownfields · 1500 ft
- APL ENGINEERED MATERIALSToxics Release Inventory · 1600 ft
- APL ENGINEERED MATERIALSBrownfields · 1600 ft
- United Waste Systems IncUnderground Storage Tanks · 1800 ft
- Frasca Air ServiceUnderground Storage Tanks · 1800 ft
- Hornes TractUnderground Storage Tanks · 1900 ft
- Interstate 74 Lift StationUnderground Storage Tanks · 0.5 mi
- Circle K #159Underground Storage Tanks · 0.6 mi
- United Fuel CoUnderground Storage Tanks · 0.6 mi
- Bailey Professional Beauty SupplyUnderground Storage Tanks · 0.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Champaign 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 Champaign County.
Total Sites
820
across Champaign County
Risk Level
Elevated
Highest-severity
3 Superfund sites (none NPL-listed)
Sources Checked
across Champaign County
Severity Distribution
across Champaign County
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
Check your specific parcel in Champaign 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 Champaign County average
Your land is one point inside Champaign County
Everything above resolves to Champaign County as a whole — one PHZM band and one county frost record, read across 638K 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 Champaign County Average
Champaign County Average
- ●USDA Zones 6a, averaged across Champaign County
- ●One soil character for all of Champaign County
- ●Frost dates read at Champaign County's scale: Apr 5 to Oct 31
YOUR Parcel
- ✓Your exact zone, not Champaign County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Champaign County
Pull a site-specific report for your exact address in Champaign County, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Champaign County averages can't show:
We read public map data around Champaign County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Champaign County average
How we know this about Champaign 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 Champaign County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Champaign County
When does frost risk typically end in Champaign County?
The last hard freeze (28°F) in Champaign County typically lands around Apr 5, 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 26.
How long is the growing season in Champaign County?
Measured between 28°F hard freezes, Champaign County sees about 209 frost-free days — roughly Apr 5 through Oct 31, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 26 to Oct 17, about 174 days.
Is the soil safe to grow vegetables in Champaign County?
The federal record around Champaign County is a meaningful one — 820 documented sites, mostly Underground Storage Tanks entries (479), the nearest Brownfields record about 0.2 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 Champaign County's scale — its 6a band and its 209-day season. Your yard writes its own version of Champaign 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 Champaign County’s own scale
9 of the readings below were taken at Champaign County's own scale — its own ~209-day span between 28°F freezes, the 3 most extensive soil series mapped here and 820 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Champaign County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Champaign County's own 28°F hard-freeze dates and its ~209-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Champaign CountyUSDA NRCS SSURGO
- 820 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Brownfields record about 0.2 miles outFederal environmental registers
- Champaign County's boundary and the 637,506 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~209-day seasonGrowable Ground crop-matching engine
- Champaign County sitting wholly inside the Central Corn Belt PlainsUS EPA Level III Ecoregions
- Open occurrence records documented in Champaign County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Champaign 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 Champaign County — the ~209 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 Champaign County's 637,506 acreswhy one lot differs from the next →
- Which of those 820 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 Champaign Countyread your own land →