Chicago, Illinois, sits in USDA hardiness zone 6a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
A short list that earns its place here — cabbage, blueberry, lavender, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Even in Chicago, no two yards are alike.
A low spot, a south-facing slope, or a stand of trees moves the frost date and sun across a single Chicago lot. 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 Chicago — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Chicago — the short answer
Chicago, Illinois: USDA zone 6a, about 234 days between hard freezes, across 146K acres of city.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 28
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 17
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~234
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 146K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are this town’s own 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 Chicago's average, not your lot's — a low corner or a tree line moves it. Against Chicago's 234-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Chicago
Each reading below is measured for Chicago itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredChicago runs about 234 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
MeasuredChicago 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 Chicago is in
Chicago sits in the Central Corn Belt Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Chicago's own centroid rather than borrowed from Cook County.
What Grows in Chicago
Every plant below cleared Chicago's own zone 6a and its 234-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Chicago?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Feb 28; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 28 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 17 — 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 Chicago
Spotted lanternfly documented 3 miles from Chicago, first recorded 2023. What to watch for.
What's on the federal record near Chicago
Closest first, within ~10 miles of Chicago. Listing isn't leaking, and distance isn't exposure.
- Gte Spacenet CorpUnderground Storage Tanks · 100 ft
- At&Sf Railroad Ash St JunctionUnderground Storage Tanks · 500 ft
- GILTSPURBrownfields · 800 ft
- GiltspurUnderground Storage Tanks · 900 ft
- HOLCO REALTY PARTNERSHIPBrownfields · 900 ft
- AMERICAN SUGAR REFINING INCBrownfields · 950 ft
- Dearborn Wholesale Grocers, Inc.Underground Storage Tanks · 1100 ft
- HAMILTON CONSTRUCTIONBrownfields · 1300 ft
- Construction SiteUnderground Storage Tanks · 1300 ft
- AMEROPAN OIL CORPORATION, INCBrownfields · 1600 ft
- Frito Lay IncUnderground Storage Tanks · 1700 ft
- ELCAMINO TRUCK SALES INCBrownfields · 1700 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Chicago'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 Chicago.
Total Sites
7,118
within ~10 miles of Chicago
Risk Level
Elevated
Highest-severity
107 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Chicago
Severity Distribution
within ~10 miles of Chicago
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Chicago, two things run higher than the national average within ~10 miles of Chicago — Toxics Release Inventory (593 sites) and Superfund (107 sites). That's not a problem with your land — it's information about 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 Chicago
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 Chicago average
Your land is one point inside Chicago
Everything above resolves to Chicago as a whole — one PHZM band and one 28°F frost record, read across 146K 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 city 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 local average.
Your Lot vs the Chicago Average
Chicago Average
- ●USDA Zones 6a, averaged across Chicago
- ●One soil character for all of Chicago
- ●Frost dates read at Chicago's scale: Mar 28 to Nov 17
YOUR Parcel
- ✓Your exact zone, not Chicago's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Chicago
Pull a site-specific report for your exact address in Chicago, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Chicago averages can't show:
We read public map data around Chicago — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Chicago average
How we know this about Chicago
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Chicago’s own record; boundaries and acreage from US Census TIGER/Line 2025; the contamination records from the federal sources named in their beats above. Soil is not read at city grain anywhere on this page — there is no city-resolution survey in our data, which is why you will find no soil grid here rather than a statewide one wearing a local label. The resolution ledger below names every figure this page inherited.
Common questions about Chicago
When does frost risk typically end in Chicago?
The last hard freeze (28°F) in Chicago typically lands around Mar 28, 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 18.
When is the first frost in Chicago?
The first hard freeze (28°F) in Chicago typically arrives around Nov 17, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 3, so the watching starts about Oct 18 — about 234 days after the spring freeze cleared.
How long is the growing season in Chicago?
Measured between 28°F hard freezes, Chicago sees about 234 frost-free days — roughly Mar 28 through Nov 17, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 18 to Nov 3, about 199 days.
Is the soil safe to grow vegetables in Chicago?
The federal record around Chicago is a meaningful one — 7,118 documented sites, mostly Underground Storage Tanks entries (3,427), the nearest Underground Storage Tanks record under a tenth of a mile 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.
How do I protect my plants from frost in Chicago?
From about Oct 18 the job here turns from planting to protecting — the last start even a 30-day crop can finish. As the season closes around the first 28°F hard freeze near Nov 17 (NOAA 1991–2020 climate normals), three moves buy time: row cover or an old sheet over tender plants on still, clear nights; water the soil the afternoon before a freeze, so it holds warmth overnight; and harvest tomatoes, peppers and basil before Nov 17. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Chicago's scale — its 6a band and its 234-day season. Your yard writes its own version of Chicago's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
What this page reads at Chicago’s own scale
7 of the readings below were taken at Chicago's own scale — its own ~234-day season between 28°F freezes, the 145,759 acres it covers and 7,118 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Chicago's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Chicago's own 28°F hard-freeze dates, about Mar 28 and Nov 17 and the ~234-day span between themNOAA 1991–2020 Climate Normals
- 7,118 documented contamination sites on the federal record near Chicago, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Chicago's boundary and the 145,759 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~234-day seasonGrowable Ground crop-matching engine
- The ecoregion at Chicago's own centroid, the Central Corn Belt PlainsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Chicagolydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Chicago's 145,759 acres read through its county's SSURGO summaryfrom Cook County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Cook County
- The growing challenges every Illinois grower plans around — written at state scale, so they stay on the state guidefrom Illinois
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Cook County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Chicago's 145,759 acreswhy one lot differs from the next →
- Which side of Chicago you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 145,759 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record under a tenth of a mile out, measured from the town centrehow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — measured at your address, and averaged away by any Chicago-wide figureread your own land →
More in Illinois
Growing region
Nearby growing guides