Lacon, Illinois, sits in USDA hardiness zone 6a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Among the crops suited to this profile: cabbage, hazelnut, lavender, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Lacon, 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 Lacon 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 Lacon — soil, climate, flood, and parcel records. How we handle your address.
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Lacon — the short answer
Lacon, Illinois: USDA zone 6a, about 209 days between hard freezes, across 1K acres of city.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 8
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 3
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~209
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 1K 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 Lacon's average, not your lot's — a low corner or a tree line moves it. Against Lacon's 209-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Lacon
Each reading below is measured for Lacon itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredLacon 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
MeasuredLacon 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 Lacon is in
Lacon sits in the Interior River Valleys and Hills — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Lacon's own centroid, and it is not what its county reads: Marshall County is mostly Central Corn Belt Plains. The wider page above you is answering a different question about different ground.
What Grows in Lacon
Every plant below cleared Lacon's own zone 6a and its 209-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Lacon?
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 11; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 8 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 3 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
What's on the federal record near Lacon
Closest first, within ~10 miles of Lacon. Listing isn't leaking, and distance isn't exposure.
- Jerome GreenUnderground Storage Tanks · 600 ft
- Casey's General StoreUnderground Storage Tanks · 750 ft
- NORCO FUELS 6Brownfields · 750 ft
- Marshall County Sheriff DeptUnderground Storage Tanks · 950 ft
- Marshall County Highway DeptUnderground Storage Tanks · 1000 ft
- Mid West Sand Lacon PlantUnderground Storage Tanks · 1000 ft
- Central TelephoneUnderground Storage Tanks · 1100 ft
- FERRELL BODY SHOPBrownfields · 1200 ft
- Casey's General Store #2548Underground Storage Tanks · 1700 ft
- King Robert E & Zelpha MUnderground Storage Tanks · 1800 ft
- Kief GarageUnderground Storage Tanks · 1800 ft
- Lacon City OfUnderground Storage Tanks · 1800 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Lacon'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 Lacon.
Total Sites
136
within ~10 miles of Lacon
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Lacon
Severity Distribution
within ~10 miles of Lacon
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Lacon, Underground Storage Tanks runs higher than the national average — 94 sites within ~10 miles of Lacon. 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 Lacon
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 Lacon average
Your land is one point inside Lacon
Everything above resolves to Lacon as a whole — one PHZM band and one 28°F frost record, read across 1K 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 Lacon Average
Lacon Average
- ●USDA Zones 6a, averaged across Lacon
- ●One soil character for all of Lacon
- ●Frost dates read at Lacon's scale: Apr 8 to Nov 3
YOUR Parcel
- ✓Your exact zone, not Lacon's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Lacon
Pull a site-specific report for your exact address in Lacon, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Lacon averages can't show:
We read public map data around Lacon — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Lacon average
How we know this about Lacon
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 Lacon’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 Lacon
When does frost risk typically end in Lacon?
The last hard freeze (28°F) in Lacon typically lands around Apr 8, 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 29.
When is the first frost in Lacon?
The first hard freeze (28°F) in Lacon typically arrives around Nov 3, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 20, so the watching starts about Oct 4 — about 209 days after the spring freeze cleared.
How long is the growing season in Lacon?
Measured between 28°F hard freezes, Lacon sees about 209 frost-free days — roughly Apr 8 through Nov 3, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 29 to Oct 20, about 174 days.
Is the soil safe to grow vegetables in Lacon?
The federal record around Lacon is a meaningful one — 136 documented sites, mostly Underground Storage Tanks entries (94), the nearest Underground Storage Tanks record about 0.1 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 Lacon?
From about Oct 4 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 3 (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 3. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Lacon's scale — its 6a band and its 209-day season. Your yard writes its own version of Lacon'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 Lacon’s own scale
6 of the readings below were taken at Lacon's own scale — its own ~209-day season between 28°F freezes, the 1,047 acres it covers and 136 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Lacon's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Lacon's own 28°F hard-freeze dates, about Apr 8 and Nov 3 and the ~209-day span between themNOAA 1991–2020 Climate Normals
- 136 documented contamination sites on the federal record near Lacon, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Lacon's boundary and the 1,047 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~209-day seasonGrowable Ground crop-matching engine
- Lacon sits in the Interior River Valleys and Hills — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Lacon's 1,047 acres read through its county's SSURGO summaryfrom Marshall County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Marshall 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 Marshall County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Lacon's 1,047 acreswhy one lot differs from the next →
- Which side of Lacon you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,047 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.1 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 Lacon-wide figureread your own land →
More in Illinois
Wider growing context
What grows across IllinoisLacon sits outside our named growing regions, so Illinois as a whole is its closest context here.
Nearby growing guides