Mendon, Illinois, sits in USDA hardiness zone 6a — a zone band wide enough that plant choice, not possibility, is the interesting question.
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 Mendon, 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 Mendon 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 Mendon — soil, climate, flood, and parcel records. How we handle your address.
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Mendon — the short answer
Mendon, Illinois: USDA zone 6a, about 218 days between hard freezes, across 548 acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 30
- 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
- ~218
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 548 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 Mendon's average, not your lot's — a low corner or a tree line moves it. Against Mendon's 218-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Mendon
Each reading below is measured for Mendon itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredMendon runs about 218 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
MeasuredMendon 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 Mendon is in
Mendon sits in the Interior River Valleys and Hills — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Mendon's own centroid rather than borrowed from Adams County.
What Grows in Mendon
Every plant below cleared Mendon's own zone 6a and its 218-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Mendon?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 2; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 30 (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. 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 Mendon
Closest first, within ~10 miles of Mendon. Listing isn't leaking, and distance isn't exposure.
- County Market Express #796Underground Storage Tanks · 500 ft
- Adams Telephone CooperativeUnderground Storage Tanks · 650 ft
- Cramm Service StationUnderground Storage Tanks · 750 ft
- Casey's General StoreUnderground Storage Tanks · 1000 ft
- MENDON FARM CENTERSuperfund · 1100 ft
- Mendon Township OfUnderground Storage Tanks · 1200 ft
- Unity High SchoolUnderground Storage Tanks · 2000 ft
- MENDONPFAS · 1.9 mi
- ADM ANIMAL NUTRITIONBrownfields · 2.3 mi
- Uspa FacilityUnderground Storage Tanks · 3.5 mi
- METZGER FARM, INC - URSACAFO · 3.5 mi
- C AND W FARMS, LLCCAFO · 3.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Mendon'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 Mendon.
Total Sites
77
within ~10 miles of Mendon
Risk Level
Elevated
Highest-severity
2 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Mendon
Severity Distribution
within ~10 miles of Mendon
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Mendon, two things run higher than the national average within ~10 miles of Mendon — CAFO (5 sites) and Toxics Release Inventory (6 sites). That's not a problem with your land — it's information about it.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Mendon
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 Mendon average
Your land is one point inside Mendon
Everything above resolves to Mendon as a whole — one PHZM band and one 28°F frost record, read across 548 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 town 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 Mendon Average
Mendon Average
- ●USDA Zones 6a, averaged across Mendon
- ●One soil character for all of Mendon
- ●Frost dates read at Mendon's scale: Mar 30 to Nov 3
YOUR Parcel
- ✓Your exact zone, not Mendon's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Mendon
Pull a site-specific report for your exact address in Mendon, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Mendon averages can't show:
We read public map data around Mendon — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Mendon average
How we know this about Mendon
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this town’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at Mendon’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 town grain anywhere on this page — there is no town-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 Mendon
When does frost risk typically end in Mendon?
The last hard freeze (28°F) in Mendon typically lands around Mar 30, 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 20.
When is the first frost in Mendon?
The first hard freeze (28°F) in Mendon 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 218 days after the spring freeze cleared.
How long is the growing season in Mendon?
Measured between 28°F hard freezes, Mendon sees about 218 frost-free days — roughly Mar 30 through Nov 3, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 20 to Oct 20, about 183 days.
Is the soil safe to grow vegetables in Mendon?
The federal record around Mendon is a meaningful one — 77 documented sites, mostly Underground Storage Tanks entries (42), 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 Mendon?
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 Mendon's scale — its 6a band and its 218-day season. Your yard writes its own version of Mendon'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 Mendon’s own scale
6 of the readings below were taken at Mendon's own scale — its own ~218-day season between 28°F freezes, the 548 acres it covers and 77 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Mendon's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Mendon's own 28°F hard-freeze dates, about Mar 30 and Nov 3 and the ~218-day span between themNOAA 1991–2020 Climate Normals
- 77 documented contamination sites on the federal record near Mendon, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Mendon's boundary and the 548 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~218-day seasonGrowable Ground crop-matching engine
- The ecoregion at Mendon'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 Mendon's 548 acres read through its county's SSURGO summaryfrom Adams County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Adams 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 Adams County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Mendon's 548 acreswhy one lot differs from the next →
- Which side of Mendon you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 548 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 Mendon-wide figureread your own land →
More in Illinois
Wider growing context
What grows across IllinoisMendon sits outside our named growing regions, so Illinois as a whole is its closest context here.
Nearby growing guides