South Holland, 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.
The conditions favor cabbage, hazelnut, lavender, and collard greens, among others — though every individual site edits that list with its own soil, sun, and drainage.
Even in South Holland, 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 South Holland 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 South Holland — soil, climate, flood, and parcel records. How we handle your address.
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South Holland — the short answer
South Holland, Illinois: USDA zone 6a, about 218 days between hard freezes, across 5K acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 4
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 8
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~218
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 5K 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 South Holland's average, not your lot's — a low corner or a tree line moves it. Against South Holland's 218-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in South Holland
Each reading below is measured for South Holland itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSouth Holland 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
MeasuredSouth Holland 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 South Holland is in
South Holland sits in the Central Corn Belt Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at South Holland's own centroid rather than borrowed from Cook County.
What Grows in South Holland
Every plant below cleared South Holland'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 South Holland?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 7; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 4 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 8 — 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.
Documented around South Holland
Spotted lanternfly documented 8 miles from South Holland, first recorded 2023. What to watch for.
What's on the federal record near South Holland
Closest first, within ~10 miles of South Holland. Listing isn't leaking, and distance isn't exposure.
- 7-Eleven Store # 34721Underground Storage Tanks · 400 ft
- 7-Eleven # 34720Underground Storage Tanks · 400 ft
- Yard CtrUnderground Storage Tanks · 400 ft
- Unoccupied Comm BldgsUnderground Storage Tanks · 900 ft
- SIMPLIFIED PERFECTION INCBrownfields · 950 ft
- PRESCOTT COToxics Release Inventory · 1000 ft
- Fisca Ooil Co Inc 44Underground Storage Tanks · 1300 ft
- Rolper Inc(Perruso Cleaners)Underground Storage Tanks · 1300 ft
- JEWEL OSCO 3063Brownfields · 1500 ft
- AmocoUnderground Storage Tanks · 1600 ft
- AVENUE MEDICAL LABBrownfields · 1700 ft
- Shell StationUnderground Storage Tanks · 1800 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from South Holland'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 South Holland.
Sources Checked
within ~10 miles of South Holland
Severity Distribution
within ~10 miles of South Holland
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around South Holland, two things run higher than the national average within ~10 miles of South Holland — Superfund (104 sites) and Toxics Release Inventory (287 sites). That's not a problem with your land — it's information about it.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in South Holland
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 South Holland average
Your land is one point inside South Holland
Everything above resolves to South Holland as a whole — one PHZM band and one 28°F frost record, read across 5K 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 South Holland Average
South Holland Average
- ●USDA Zones 6a, averaged across South Holland
- ●One soil character for all of South Holland
- ●Frost dates read at South Holland's scale: Apr 4 to Nov 8
YOUR Parcel
- ✓Your exact zone, not South Holland's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in South Holland
Pull a site-specific report for your exact address in South Holland, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that South Holland averages can't show:
We read public map data around South Holland — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the South Holland average
How we know this about South Holland
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 South Holland’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 South Holland
When does frost risk typically end in South Holland?
The last hard freeze (28°F) in South Holland typically lands around Apr 4, 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 25.
When is the first frost in South Holland?
The first hard freeze (28°F) in South Holland typically arrives around Nov 8, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 25, so the watching starts about Oct 9 — about 218 days after the spring freeze cleared.
How long is the growing season in South Holland?
Measured between 28°F hard freezes, South Holland sees about 218 frost-free days — roughly Apr 4 through Nov 8, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 25 to Oct 25, about 183 days.
Is the soil safe to grow vegetables in South Holland?
The federal record around South Holland runs heavier than most — 3,702 documented sites, mostly Underground Storage Tanks entries (1,840), the nearest Underground Storage Tanks record under a tenth of a mile out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do I protect my plants from frost in South Holland?
From about Oct 9 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 8 (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 8. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at South Holland's scale — its 6a band and its 218-day season. Your yard writes its own version of South Holland'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 South Holland’s own scale
7 of the readings below were taken at South Holland's own scale — its own ~218-day season between 28°F freezes, the 4,631 acres it covers and 3,702 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- South Holland's own USDA hardiness band, zones 6aUSDA PHZM 2023
- South Holland's own 28°F hard-freeze dates, about Apr 4 and Nov 8 and the ~218-day span between themNOAA 1991–2020 Climate Normals
- 3,702 documented contamination sites on the federal record near South Holland, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- South Holland's boundary and the 4,631 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 South Holland's own centroid, the Central Corn Belt PlainsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of South Hollandlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so South Holland's 4,631 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 South Holland's 4,631 acreswhy one lot differs from the next →
- Which side of South Holland you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 4,631 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 South Holland-wide figureread your own land →
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