Macon 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
Macon County holds more than one microclimate.
Soils and elevations shift across Macon 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 Macon County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Macon County — the short answer
Macon County, Illinois: USDA zone 6a, about 212 days between hard freezes, across 372K acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 4
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 2
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~212
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 372K 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 Macon County's average, not your lot's — a low corner or a tree line moves it. Against Macon County's 212-day season, see what your own ground reads.
Heat in Macon County
Across a year, Macon County accumulates about 3,424 growing degree days above 50°F, about 41 more than the middle Illinois county — ahead of 53 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 Macon County
Across Macon County, the ground is predominantly Mollisols, where Flanagan, Drummer, and Sable are the most extensive named soil series. The soil is generally poorly drained with a silt 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
47%
Hydric soils
40%
Soil still varies lot by lot — soil types explained.
How the ground varies across Macon County
The USDA soil survey maps 39% of Macon County as poorly drained — but another 59% drains differently: 34% somewhat poorly drained, 14% moderately well drained.
Flanagan is the most extensive named soil at 20% of mapped acres, then Drummer (17%) and Sable (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 Macon County
Each reading below is measured for Macon 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 Macon 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 Macon 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
MeasuredMacon County runs about 212 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
MeasuredMacon 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 Macon County is in
Macon 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 Macon County
We scored all 1,086 plants against Macon County's own USDA zone 6a and its own 212-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 Macon County?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Mar 7; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 4 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 2 — long-season crops need about 90 days of runway, quick greens only 30. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.
Documented around Macon County
- Japanese beetle1 documented records
- monarch butterfly17 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Macon County
USGS estimates 338,120 lb of Glyphosate on Macon County farmland in 2019, its largest by weight, ahead of Atrazine (148,203 lb) and Metolachlor & Metolachlor-s (139,100 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 Macon County — and how to grow with it.
We checked the federal record across Macon County — 616 documented sites across 6 of the 9 source types we track.
The most significant on record: 9 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 Macon 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 Macon County
Closest first, across Macon County. Listing isn't leaking, and distance isn't exposure.
- Vanco StationUnderground Storage Tanks · 1500 ft
- Leisher Oil CoUnderground Storage Tanks · 1500 ft
- Mid States Gen & Mech Ctr CoUnderground Storage Tanks · 1600 ft
- Traver Supply IncUnderground Storage Tanks · 1900 ft
- Harper Oil #15Underground Storage Tanks · 2000 ft
- Maple Investment L CUnderground Storage Tanks · 2400 ft
- Decatur Memorial HospitalUnderground Storage Tanks · 2400 ft
- DECATUR MEMORIAL HOSPITALBrownfields · 2500 ft
- SOFIE CO DBA SOFIEBrownfields · 2500 ft
- NEWELLS BODY SHOPBrownfields · 2500 ft
- Quick Shop 66Underground Storage Tanks · 0.5 mi
- Tallman Pontiac CadillacUnderground Storage Tanks · 0.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Macon 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 Macon County.
Total Sites
616
across Macon County
Risk Level
Elevated
Highest-severity
9 Superfund sites (none NPL-listed)
Sources Checked
across Macon County
Severity Distribution
across Macon County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Macon County, two things run higher than the national average across Macon County — Superfund (9 sites) and Toxics Release Inventory (40 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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 Macon 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 Macon County average
Your land is one point inside Macon County
Everything above resolves to Macon County as a whole — one PHZM band and one county frost record, read across 372K 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 Macon County Average
Macon County Average
- ●USDA Zones 6a, averaged across Macon County
- ●One soil character for all of Macon County
- ●Frost dates read at Macon County's scale: Apr 4 to Nov 2
YOUR Parcel
- ✓Your exact zone, not Macon County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Macon County
Pull a site-specific report for your exact address in Macon County, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Macon County averages can't show:
We read public map data around Macon County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Macon County average
How we know this about Macon 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 Macon County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Macon County
When does frost risk typically end in Macon County?
The last hard freeze (28°F) in Macon County typically lands around Apr 4, 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 25.
How long is the growing season in Macon County?
Measured between 28°F hard freezes, Macon County sees about 212 frost-free days — roughly Apr 4 through Nov 2, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 25 to Oct 19, about 177 days.
Is the soil safe to grow vegetables in Macon County?
The federal record around Macon County is a meaningful one — 616 documented sites, mostly Underground Storage Tanks entries (354), the nearest Underground Storage Tanks record about 0.3 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 Macon County's scale — its 6a band and its 212-day season. Your yard writes its own version of Macon 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 Macon County’s own scale
9 of the readings below were taken at Macon County's own scale — its own ~212-day span between 28°F freezes, the 3 most extensive soil series mapped here and 616 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Macon County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Macon County's own 28°F hard-freeze dates and its ~212-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Macon CountyUSDA NRCS SSURGO
- 616 documented contamination sites inside the county boundary, distance-sorted from its center — the closest Underground Storage Tanks record about 0.3 miles outFederal environmental registers
- Macon County's boundary and the 371,551 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~212-day seasonGrowable Ground crop-matching engine
- Macon County sitting wholly inside the Central Corn Belt PlainsUS EPA Level III Ecoregions
- Open occurrence records documented in Macon County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Macon 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 Macon County — the ~212 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 Macon County's 371,551 acreswhy one lot differs from the next →
- Which of those 616 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 Macon Countyread your own land →