Sandwich, Illinois, sits in USDA hardiness zone 5b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
On paper, cabbage, cranberry, lavender, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Sandwich, 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 Sandwich 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 Sandwich — soil, climate, flood, and parcel records. How we handle your address.
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Sandwich — the short answer
Sandwich, Illinois: USDA zone 5b, about 196 days between hard freezes, across 3K acres of city.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 11
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 24
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~196
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 3K 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 5b is Sandwich's average, not your lot's — a low corner or a tree line moves it. Against Sandwich's 196-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Sandwich
Each reading below is measured for Sandwich itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSandwich runs about 196 days between hard freezes — a moderate growing season.
There is room for the full run of cool-season crops plus a warm-season main crop, but the calendar is tight enough that a late spring or early fall frost still decides how much finishes.
Time warm-season transplants to your last hard freeze, and a few weeks of season extension turns a near-miss harvest into a sure one.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredSandwich sits in USDA hardiness zone 5b.
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 Sandwich is in
Sandwich sits in the Central Corn Belt Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Sandwich's own centroid rather than borrowed from DeKalb County.
What Grows in Sandwich
Every plant below cleared Sandwich's own zone 5b and its 196-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Sandwich?
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 14; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 11 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 24 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
Documented around Sandwich
Spotted lanternfly documented 22 miles from Sandwich, first recorded 2023. What to watch for.
What's on the federal record near Sandwich
Closest first, within ~10 miles of Sandwich. Listing isn't leaking, and distance isn't exposure.
- Former A and J AutomotiveUnderground Storage Tanks · 1300 ft
- UZ Management, Inc. d/b/a Sandwich Food MartUnderground Storage Tanks · 1400 ft
- HENDERSON ENGINEERING CO INCBrownfields · 1500 ft
- A FUSSY CLEANERSBrownfields · 1600 ft
- 37N 5E-36.7h1Nitrate · 1700 ft
- City GarageUnderground Storage Tanks · 1700 ft
- Olaf Gjovik Chevrolet-OldsincUnderground Storage Tanks · 2100 ft
- Woodlake Landing AirportUnderground Storage Tanks · 2100 ft
- Sandwich AirportUnderground Storage Tanks · 2100 ft
- Sandwich Township GarageUnderground Storage Tanks · 2100 ft
- P S Lindner CoUnderground Storage Tanks · 2100 ft
- LEE AUTO PARTSBrownfields · 2200 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Sandwich'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 Sandwich.
Total Sites
229
within ~10 miles of Sandwich
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Sandwich
Severity Distribution
within ~10 miles of Sandwich
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Sandwich, two things run higher than the national average within ~10 miles of Sandwich — PFAS (3 sites) and CAFO (3 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.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Check your specific parcel in Sandwich
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 Sandwich average
Your land is one point inside Sandwich
Everything above resolves to Sandwich as a whole — one PHZM band and one 28°F frost record, read across 3K 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 Sandwich Average
Sandwich Average
- ●USDA Zones 5b, averaged across Sandwich
- ●One soil character for all of Sandwich
- ●Frost dates read at Sandwich's scale: Apr 11 to Oct 24
YOUR Parcel
- ✓Your exact zone, not Sandwich's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Sandwich
Pull a site-specific report for your exact address in Sandwich, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Sandwich averages can't show:
We read public map data around Sandwich — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Sandwich average
How we know this about Sandwich
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 Sandwich’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 Sandwich
When does frost risk typically end in Sandwich?
The last hard freeze (28°F) in Sandwich typically lands around Apr 11, 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 May 2.
When is the first frost in Sandwich?
The first hard freeze (28°F) in Sandwich typically arrives around Oct 24, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 10, so the watching starts about Sep 24 — about 196 days after the spring freeze cleared.
How long is the growing season in Sandwich?
Measured between 28°F hard freezes, Sandwich sees about 196 frost-free days — roughly Apr 11 through Oct 24, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 2 to Oct 10, about 161 days.
Is the soil safe to grow vegetables in Sandwich?
The federal record around Sandwich is a meaningful one — 229 documented sites, mostly Underground Storage Tanks entries (133), 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 Sandwich?
From about Sep 24 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 Oct 24 (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 Oct 24. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Sandwich's scale — its 5b band and its 196-day season. Your yard writes its own version of Sandwich'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 Sandwich’s own scale
7 of the readings below were taken at Sandwich's own scale — its own ~196-day season between 28°F freezes, the 3,031 acres it covers and 229 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Sandwich's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Sandwich's own 28°F hard-freeze dates, about Apr 11 and Oct 24 and the ~196-day span between themNOAA 1991–2020 Climate Normals
- 229 documented contamination sites on the federal record near Sandwich, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Sandwich's boundary and the 3,031 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~196-day seasonGrowable Ground crop-matching engine
- The ecoregion at Sandwich's own centroid, the Central Corn Belt PlainsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Sandwichlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Sandwich's 3,031 acres read through its county's SSURGO summaryfrom DeKalb County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom DeKalb 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 DeKalb County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Sandwich's 3,031 acreswhy one lot differs from the next →
- Which side of Sandwich you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,031 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 Sandwich-wide figureread your own land →
More in Illinois
Wider growing context
What grows across IllinoisSandwich sits outside our named growing regions, so Illinois as a whole is its closest context here.
Nearby growing guides