Greene County, in Illinois, sits in USDA hardiness zone 6a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Expect cabbage, hazelnut, lavender, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Greene County holds more than one microclimate.
Soils and elevations shift across Greene 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 Greene County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Greene County — the short answer
Greene County, Illinois: USDA zone 6a, about 217 days between hard freezes, across 348K acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 29
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 1
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~217
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 348K 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 Greene County's average, not your lot's — a low corner or a tree line moves it. Against Greene County's 217-day season, see what your own ground reads.
Heat in Greene County
Across a year, Greene County accumulates about 3,541 growing degree days above 50°F, about 158 more than the middle Illinois county — ahead of 59 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 Greene County
Across Greene County, the ground is predominantly Alfisols, where Fayette, Rozetta, and Muscatune are the most extensive named soil series. The soil is generally well drained with a silt loam surface. Topsoil pH runs about 6.2–6.8, slightly acidic. Rainfall drains through hydrologic group B soils.
Soil order
Alfisols
Drainage
Well drained
Prime farmland
29%
Hydric soils
17%
Soil still varies lot by lot — soil types explained.
How the ground varies across Greene County
The USDA soil survey maps 49% of Greene County as well drained — but another 50% drains differently: 33% somewhat poorly drained, 17% poorly drained.
Fayette is the most extensive named soil at 17% of mapped acres, then Rozetta (12%) and Muscatune (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 Greene County
Each reading below is measured for Greene 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 Greene County are well drained, in hydrologic group B — 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 Greene 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
Wet ground
MeasuredAbout 17% of Greene County is mapped as hydric — wetland — soil.
If your lot falls in one of those pockets, a standard in-ground bed will fight waterlogging all season, and roots that need air will struggle.
Check how your own ground drains before you dig; raised beds or moisture-loving plantings turn a wet corner from a problem into a niche.
USDA NRCS SSURGO
Season length
MeasuredGreene County runs about 217 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
The kind of country Greene County is in
Greene County sits in the Interior River Valleys and Hills — EPA Level III, inside the wider Eastern Temperate Forests. One consistent ecological setting across the whole county.
What Grows in Greene County
We scored all 1,086 plants against Greene County's own USDA zone 6a and its own 217-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 Greene County?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 29 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 1 — 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.
What gets applied to farmland in Greene County
USGS estimates 171,818 lb of Glyphosate on Greene County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (84,481 lb) and Atrazine (79,093 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 Greene County — and how to grow with it.
We checked the federal record across Greene County — 90 documented sites across 4 of the 9 source types we track.
The most significant on record: 13 brownfield sites. Former commercial or industrial land where legacy contamination may persist.
The federal record across Greene County is a modest one — a typical footprint for a growing area. Nothing here calls for alarm; it's worth knowing which recorded sites sit closest to where you grow, and each one on the map carries its type and location. If one turns out to be a near neighbor, a one-time soil test settles the question.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Greene County
Closest first, across Greene County. Listing isn't leaking, and distance isn't exposure.
- Curtright MarathonUnderground Storage Tanks · 3.7 mi
- Isringhausen Tire CtrUnderground Storage Tanks · 3.8 mi
- ILDOTBrownfields · 3.8 mi
- GTE NorthUnderground Storage Tanks · 3.9 mi
- Gillingham Oil Co IncUnderground Storage Tanks · 3.9 mi
- Jiffi Stop #575Underground Storage Tanks · 3.9 mi
- KROGER STORE 438Brownfields · 3.9 mi
- Carrollton Township OfUnderground Storage Tanks · 3.9 mi
- Greene County Sheriff DeptUnderground Storage Tanks · 3.9 mi
- Greene County Highway DeptUnderground Storage Tanks · 4.0 mi
- Evans Farm Equipment CoUnderground Storage Tanks · 4.0 mi
- Carrollton Moto MartUnderground Storage Tanks · 4.0 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Greene 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 Greene County.
Sources Checked
across Greene County
Severity Distribution
across Greene County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Greene County, Underground Storage Tanks runs higher than the national average — 68 sites across Greene County. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Greene 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 Greene County average
Your land is one point inside Greene County
Everything above resolves to Greene County as a whole — one PHZM band and one county frost record, read across 348K 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 Greene County Average
Greene County Average
- ●USDA Zones 6a, averaged across Greene County
- ●One soil character for all of Greene County
- ●Frost dates read at Greene County's scale: Mar 29 to Nov 1
YOUR Parcel
- ✓Your exact zone, not Greene County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Greene County
Pull a site-specific report for your exact address in Greene County, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Greene County averages can't show:
We read public map data around Greene County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Greene County average
How we know this about Greene 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 Greene County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Greene County
When does frost risk typically end in Greene County?
The last hard freeze (28°F) in Greene County typically lands around Mar 29, 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 19.
How long is the growing season in Greene County?
Measured between 28°F hard freezes, Greene County sees about 217 frost-free days — roughly Mar 29 through Nov 1, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 19 to Oct 18, about 182 days.
Is the soil safe to grow vegetables in Greene County?
The federal record around Greene County shows 90 documented sites, mostly Underground Storage Tanks entries (68), the nearest Underground Storage Tanks record about 3.7 miles out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
Everything above is measured at Greene County's scale — its 6a band and its 217-day season. Your yard writes its own version of Greene 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 Greene County’s own scale
8 of the readings below were taken at Greene County's own scale — its own ~217-day span between 28°F freezes, the 3 most extensive soil series mapped here and 90 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Greene County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Greene County's own 28°F hard-freeze dates and its ~217-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Greene CountyUSDA NRCS SSURGO
- 90 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 3.7 miles outFederal environmental registers
- Greene County's boundary and the 347,612 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~217-day seasonGrowable Ground crop-matching engine
- Greene County sitting wholly inside the Interior River Valleys and HillsUS EPA Level III Ecoregions
- Which agricultural compounds go onto Greene 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 Greene County — the ~217 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 Greene County's 347,612 acreswhy one lot differs from the next →
- Which of those 90 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 Greene Countyread your own land →