Third Lake, Illinois, sits in USDA hardiness zone 5b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Crops well matched to these conditions include cabbage, cranberry, lavender, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Even in Third Lake, 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 Third Lake 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 Third Lake — soil, climate, flood, and parcel records. How we handle your address.
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Third Lake — the short answer
Third Lake, Illinois: USDA zone 5b, about 200 days between hard freezes, across 376 acres of town.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 12
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 29
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~200
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 376 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 Third Lake's average, not your lot's — a low corner or a tree line moves it. Against Third Lake's 200-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Third Lake
Each reading below is measured for Third Lake itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredThird Lake runs about 200 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
MeasuredThird Lake 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 Third Lake is in
Third Lake sits in the Southeastern Wisconsin Till Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Third Lake's own centroid rather than borrowed from Lake County.
What Grows in Third Lake
Every plant below cleared Third Lake's own zone 5b and its 200-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Third Lake?
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 15; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 12 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 29 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
Documented around Third Lake
Spotted lanternfly documented 19 miles from Third Lake, first recorded 2023. What to watch for.
What's on the federal record near Third Lake
Closest first, within ~10 miles of Third Lake. Listing isn't leaking, and distance isn't exposure.
- PLATINUM COLLISION EXPRESS INCBrownfields · 0.5 mi
- COLLEGE OF LAKE COUNTYBrownfields · 0.7 mi
- LAKE COUNTY VOCATIONAL CENTERBrownfields · 0.7 mi
- Lake Co High Schools Tech CampusUnderground Storage Tanks · 0.7 mi
- CVS PHARMACY 2900Brownfields · 0.7 mi
- IL0082Underground Storage Tanks · 0.8 mi
- Thornton's #308Underground Storage Tanks · 0.8 mi
- Amoco SS #16415, Fac#24822Underground Storage Tanks · 0.8 mi
- Gages Lake Quik ShopUnderground Storage Tanks · 1.0 mi
- WEST SHORE PIPELINE CO LINDENHURST STBrownfields · 1.1 mi
- Lake Villa P @ Route 45 (SS#140)Underground Storage Tanks · 1.2 mi
- HENDERSON JOSEPH & SON INCBrownfields · 1.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Third Lake'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 Third Lake.
Sources Checked
within ~10 miles of Third Lake
Severity Distribution
within ~10 miles of Third Lake
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Third Lake, two things run higher than the national average within ~10 miles of Third Lake — PFAS (23 sites) and Superfund (23 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Third Lake
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 Third Lake average
Your land is one point inside Third Lake
Everything above resolves to Third Lake as a whole — one PHZM band and one 28°F frost record, read across 376 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 Third Lake Average
Third Lake Average
- ●USDA Zones 5b, averaged across Third Lake
- ●One soil character for all of Third Lake
- ●Frost dates read at Third Lake's scale: Apr 12 to Oct 29
YOUR Parcel
- ✓Your exact zone, not Third Lake's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Third Lake
Pull a site-specific report for your exact address in Third Lake, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Third Lake averages can't show:
We read public map data around Third Lake — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Third Lake average
How we know this about Third Lake
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 Third Lake’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 Third Lake
When does frost risk typically end in Third Lake?
The last hard freeze (28°F) in Third Lake typically lands around Apr 12, 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 3.
When is the first frost in Third Lake?
The first hard freeze (28°F) in Third Lake typically arrives around Oct 29, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 15, so the watching starts about Sep 29 — about 200 days after the spring freeze cleared.
How long is the growing season in Third Lake?
Measured between 28°F hard freezes, Third Lake sees about 200 frost-free days — roughly Apr 12 through Oct 29, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 3 to Oct 15, about 165 days.
Is the soil safe to grow vegetables in Third Lake?
The federal record around Third Lake runs heavier than most — 1,560 documented sites, mostly Underground Storage Tanks entries (786), the nearest Brownfields record about 0.5 miles 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 Third Lake?
From about Sep 29 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 29 (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 29. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Third Lake's scale — its 5b band and its 200-day season. Your yard writes its own version of Third Lake'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 Third Lake’s own scale
7 of the readings below were taken at Third Lake's own scale — its own ~200-day season between 28°F freezes, the 376 acres it covers and 1,560 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Third Lake's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Third Lake's own 28°F hard-freeze dates, about Apr 12 and Oct 29 and the ~200-day span between themNOAA 1991–2020 Climate Normals
- 1,560 documented contamination sites on the federal record near Third Lake, the closest Brownfields record about 0.5 miles out from the town centreFederal environmental registers
- Third Lake's boundary and the 376 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~200-day seasonGrowable Ground crop-matching engine
- The ecoregion at Third Lake's own centroid, the Southeastern Wisconsin Till PlainsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Third Lakelydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Third Lake's 376 acres read through its county's SSURGO summaryfrom Lake County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Lake 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 Lake County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Third Lake's 376 acreswhy one lot differs from the next →
- Which side of Third Lake you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 376 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.5 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 Third Lake-wide figureread your own land →