Island Lake, 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.
Reliable performers under these conditions include cabbage, cranberry, lavender, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Island 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 Island 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 Island Lake — soil, climate, flood, and parcel records. How we handle your address.
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Island Lake — the short answer
Island Lake, Illinois: USDA zone 5b, about 189 days between hard freezes, across 2K acres of town.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 16
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 22
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~189
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 2K 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 Island Lake's average, not your lot's — a low corner or a tree line moves it. Against Island Lake's 189-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Island Lake
Each reading below is measured for Island Lake itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredIsland Lake runs about 189 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
MeasuredIsland 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 Island Lake is in
Island Lake sits in the Southeastern Wisconsin Till Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Island Lake's own centroid rather than borrowed from McHenry County.
What Grows in Island Lake
Every plant below cleared Island Lake's own zone 5b and its 189-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Island 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 19; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 16 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 22 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
Documented around Island Lake
Spotted lanternfly documented 24 miles from Island Lake, first recorded 2023. What to watch for.
What's on the federal record near Island Lake
Closest first, within ~10 miles of Island Lake. Listing isn't leaking, and distance isn't exposure.
- ISLAND LAKEPFAS · 1400 ft
- COLONIAL SERVICESBrownfields · 1700 ft
- U.S. Citgo Oil, Inc.Underground Storage Tanks · 2000 ft
- AMERICAS AUTO SVCBrownfields · 2600 ft
- Amrichs Island Lake Auto Ser IncUnderground Storage Tanks · 0.5 mi
- Lake County Mart, Inc.Underground Storage Tanks · 0.6 mi
- Don Bass Trucking IncUnderground Storage Tanks · 0.6 mi
- Pesz Joseph MUnderground Storage Tanks · 0.6 mi
- State Road Service, Inc.Underground Storage Tanks · 0.7 mi
- CUSTOM CLASSICSBrownfields · 0.7 mi
- Island Lake Sanitary DistUnderground Storage Tanks · 0.8 mi
- 44N9E-20.7cNitrate · 0.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Island 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 Island Lake.
Sources Checked
within ~10 miles of Island Lake
Severity Distribution
within ~10 miles of Island Lake
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Island Lake, two things run higher than the national average within ~10 miles of Island Lake — PFAS (20 sites) and Toxics Release Inventory (80 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.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Island 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 Island Lake average
Your land is one point inside Island Lake
Everything above resolves to Island Lake as a whole — one PHZM band and one 28°F frost record, read across 2K 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 Island Lake Average
Island Lake Average
- ●USDA Zones 5b, averaged across Island Lake
- ●One soil character for all of Island Lake
- ●Frost dates read at Island Lake's scale: Apr 16 to Oct 22
YOUR Parcel
- ✓Your exact zone, not Island Lake's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Island Lake
Pull a site-specific report for your exact address in Island Lake, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Island Lake averages can't show:
We read public map data around Island Lake — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Island Lake average
How we know this about Island 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 Island 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 Island Lake
When does frost risk typically end in Island Lake?
The last hard freeze (28°F) in Island Lake typically lands around Apr 16, 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 7.
When is the first frost in Island Lake?
The first hard freeze (28°F) in Island Lake typically arrives around Oct 22, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 8, so the watching starts about Sep 22 — about 189 days after the spring freeze cleared.
How long is the growing season in Island Lake?
Measured between 28°F hard freezes, Island Lake sees about 189 frost-free days — roughly Apr 16 through Oct 22, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 7 to Oct 8, about 154 days.
Is the soil safe to grow vegetables in Island Lake?
The federal record around Island Lake runs heavier than most — 1,290 documented sites, mostly Underground Storage Tanks entries (625), the nearest PFAS record about 0.3 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 Island Lake?
From about Sep 22 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 22 (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 22. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Island Lake's scale — its 5b band and its 189-day season. Your yard writes its own version of Island 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 Island Lake’s own scale
7 of the readings below were taken at Island Lake's own scale — its own ~189-day season between 28°F freezes, the 2,156 acres it covers and 1,290 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Island Lake's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Island Lake's own 28°F hard-freeze dates, about Apr 16 and Oct 22 and the ~189-day span between themNOAA 1991–2020 Climate Normals
- 1,290 documented contamination sites on the federal record near Island Lake, the closest PFAS record about 0.3 miles out from the town centreFederal environmental registers
- Island Lake's boundary and the 2,156 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~189-day seasonGrowable Ground crop-matching engine
- The ecoregion at Island Lake's own centroid, the Southeastern Wisconsin Till PlainsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Island Lakelydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Island Lake's 2,156 acres read through its county's SSURGO summaryfrom McHenry County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom McHenry 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 McHenry County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Island Lake's 2,156 acreswhy one lot differs from the next →
- Which side of Island 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 2,156 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest PFAS record about 0.3 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 Island Lake-wide figureread your own land →
More in Illinois
Wider growing context
What grows across IllinoisIsland Lake sits outside our named growing regions, so Illinois as a whole is its closest context here.
Nearby growing guides