Carbondale, Illinois, sits in USDA hardiness zone 7a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Among the crops suited to this profile: cabbage, hazelnut, california poppy, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Carbondale, 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 Carbondale 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 Carbondale — soil, climate, flood, and parcel records. How we handle your address.
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Carbondale — the short answer
Carbondale, Illinois: USDA zone 7a, about 220 days between hard freezes, across 11K acres of city.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 27
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 2
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~220
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 11K 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 7a is Carbondale's average, not your lot's — a low corner or a tree line moves it. Against Carbondale's 220-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Carbondale
Each reading below is measured for Carbondale itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredCarbondale runs about 220 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
MeasuredCarbondale sits in USDA hardiness zone 7a.
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 Carbondale is in
Carbondale sits in the Interior River Valleys and Hills — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Carbondale's own centroid rather than borrowed from Jackson County.
What Grows in Carbondale
Every plant below cleared Carbondale's own zone 7a and its 220-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Carbondale?
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 Feb 27; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 27 (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. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
What's on the federal record near Carbondale
Closest first, within ~10 miles of Carbondale. Listing isn't leaking, and distance isn't exposure.
- Carbondale TowersUnderground Storage Tanks · 1100 ft
- Giant City School Dist 130Underground Storage Tanks · 1300 ft
- Gas & Storage ResidenceUnderground Storage Tanks · 1300 ft
- Carbonbdale Ready MixUnderground Storage Tanks · 1300 ft
- Walnut Research CenterUnderground Storage Tanks · 1300 ft
- Playport MarinaUnderground Storage Tanks · 1300 ft
- Southern Il UniversityUnderground Storage Tanks · 1300 ft
- Keith KemperUnderground Storage Tanks · 1300 ft
- Corner Express IncUnderground Storage Tanks · 1300 ft
- Images MarineUnderground Storage Tanks · 1300 ft
- Walnut Tree Improvement CenterUnderground Storage Tanks · 1300 ft
- Marathon Unit #2006Underground Storage Tanks · 1700 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Carbondale'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 Carbondale.
Total Sites
266
within ~10 miles of Carbondale
Risk Level
Elevated
Highest-severity
3 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Carbondale
Severity Distribution
within ~10 miles of Carbondale
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Carbondale, two things run higher than the national average within ~10 miles of Carbondale — PFAS (4 sites) and Underground Storage Tanks (179 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Carbondale
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 Carbondale average
Your land is one point inside Carbondale
Everything above resolves to Carbondale as a whole — one PHZM band and one 28°F frost record, read across 11K 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 Carbondale Average
Carbondale Average
- ●USDA Zones 7a, averaged across Carbondale
- ●One soil character for all of Carbondale
- ●Frost dates read at Carbondale's scale: Mar 27 to Nov 2
YOUR Parcel
- ✓Your exact zone, not Carbondale's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Carbondale
Pull a site-specific report for your exact address in Carbondale, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Carbondale averages can't show:
We read public map data around Carbondale — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Carbondale average
How we know this about Carbondale
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 Carbondale’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 Carbondale
When does frost risk typically end in Carbondale?
The last hard freeze (28°F) in Carbondale typically lands around Mar 27, 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 17.
When is the first frost in Carbondale?
The first hard freeze (28°F) in Carbondale typically arrives around Nov 2, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 19, so the watching starts about Oct 3 — about 220 days after the spring freeze cleared.
How long is the growing season in Carbondale?
Measured between 28°F hard freezes, Carbondale sees about 220 frost-free days — roughly Mar 27 through Nov 2, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 17 to Oct 19, about 185 days.
Is the soil safe to grow vegetables in Carbondale?
The federal record around Carbondale is a meaningful one — 266 documented sites, mostly Underground Storage Tanks entries (179), the nearest Underground Storage Tanks 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.
How do I protect my plants from frost in Carbondale?
From about Oct 3 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 2 (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 2. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Carbondale's scale — its 7a band and its 220-day season. Your yard writes its own version of Carbondale'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 Carbondale’s own scale
6 of the readings below were taken at Carbondale's own scale — its own ~220-day season between 28°F freezes, the 11,187 acres it covers and 266 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Carbondale's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Carbondale's own 28°F hard-freeze dates, about Mar 27 and Nov 2 and the ~220-day span between themNOAA 1991–2020 Climate Normals
- 266 documented contamination sites on the federal record near Carbondale, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Carbondale's boundary and the 11,187 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~220-day seasonGrowable Ground crop-matching engine
- The ecoregion at Carbondale's own centroid, the Interior River Valleys and HillsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Carbondale's 11,187 acres read through its county's SSURGO summaryfrom Jackson County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Jackson 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 Jackson County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Carbondale's 11,187 acreswhy one lot differs from the next →
- Which side of Carbondale you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 11,187 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 miles 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 Carbondale-wide figureread your own land →