Highland Park, Illinois, sits in USDA hardiness zone 6a — a zone band wide enough that plant choice, not possibility, is the interesting question.
On paper, cabbage, hazelnut, lavender, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Highland Park, 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 Highland Park 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 Highland Park — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Highland Park — the short answer
Highland Park, Illinois: USDA zone 6a, about 208 days between hard freezes, across 8K acres of city.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 8
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 2
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~208
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 8K 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 Highland Park's average, not your lot's — a low corner or a tree line moves it. Against Highland Park's 208-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Highland Park
Each reading below is measured for Highland Park itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHighland Park runs about 208 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
MeasuredHighland Park 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 Highland Park is in
Highland Park sits in the Central Corn Belt Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Highland Park's own centroid, and it is not what its county reads: Lake County is mostly Southeastern Wisconsin Till Plains. The wider page above you is answering a different question about different ground.
What Grows in Highland Park
Every plant below cleared Highland Park's own zone 6a and its 208-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Highland Park?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 11; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 8 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 2 — 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 Highland Park
Spotted lanternfly documented 3 miles from Highland Park, first recorded 2023. What to watch for.
What's on the federal record near Highland Park
Closest first, within ~10 miles of Highland Park. Listing isn't leaking, and distance isn't exposure.
- HP OilUnderground Storage Tanks · 2000 ft
- Park District of Highland Park-Maint. FacilityUnderground Storage Tanks · 2300 ft
- Leonards Union 76Underground Storage Tanks · 2400 ft
- BP Highland Park (SS# 278)Underground Storage Tanks · 2400 ft
- Highland Park HospitalUnderground Storage Tanks · 2500 ft
- BEM I, LLCUnderground Storage Tanks · 2600 ft
- COMED HIGHLAND PARK REPORTING CTRBrownfields · 2600 ft
- Midtown Ser IncUnderground Storage Tanks · 0.5 mi
- Il Bell Telephone CoUnderground Storage Tanks · 0.5 mi
- Hollander & Company, Inc.Underground Storage Tanks · 0.6 mi
- SHERWIN WILLIAMS 1900Brownfields · 0.6 mi
- HIGHLAND PARK HOSPITALBrownfields · 0.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Highland Park'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 Highland Park.
Total Sites
1,913
within ~10 miles of Highland Park
Risk Level
Elevated
Highest-severity
12 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Highland Park
Severity Distribution
within ~10 miles of Highland Park
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Highland Park, two things run higher than the national average within ~10 miles of Highland Park — PFAS (22 sites) and Toxics Release Inventory (127 sites). That's not a problem with your land — it's information about 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 Highland Park
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 Highland Park average
Your land is one point inside Highland Park
Everything above resolves to Highland Park as a whole — one PHZM band and one 28°F frost record, read across 8K 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 Highland Park Average
Highland Park Average
- ●USDA Zones 6a, averaged across Highland Park
- ●One soil character for all of Highland Park
- ●Frost dates read at Highland Park's scale: Apr 8 to Nov 2
YOUR Parcel
- ✓Your exact zone, not Highland Park's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Highland Park
Pull a site-specific report for your exact address in Highland Park, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Highland Park averages can't show:
We read public map data around Highland Park — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Highland Park average
How we know this about Highland Park
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 Highland Park’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 Highland Park
When does frost risk typically end in Highland Park?
The last hard freeze (28°F) in Highland Park typically lands around Apr 8, 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 29.
When is the first frost in Highland Park?
The first hard freeze (28°F) in Highland Park typically arrives around Nov 2, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 19, so the watching starts about Oct 3 — about 208 days after the spring freeze cleared.
How long is the growing season in Highland Park?
Measured between 28°F hard freezes, Highland Park sees about 208 frost-free days — roughly Apr 8 through Nov 2, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 29 to Oct 19, about 173 days.
Is the soil safe to grow vegetables in Highland Park?
The federal record around Highland Park is a meaningful one — 1,913 documented sites, mostly Underground Storage Tanks entries (954), the nearest Underground Storage Tanks record about 0.4 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 Highland Park?
From about Oct 3 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 2 (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 2. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Highland Park's scale — its 6a band and its 208-day season. Your yard writes its own version of Highland Park'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 Highland Park’s own scale
7 of the readings below were taken at Highland Park's own scale — its own ~208-day season between 28°F freezes, the 7,830 acres it covers and 1,913 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Highland Park's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Highland Park's own 28°F hard-freeze dates, about Apr 8 and Nov 2 and the ~208-day span between themNOAA 1991–2020 Climate Normals
- 1,913 documented contamination sites on the federal record near Highland Park, the closest Underground Storage Tanks record about 0.4 miles out from the town centreFederal environmental registers
- Highland Park's boundary and the 7,830 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~208-day seasonGrowable Ground crop-matching engine
- Highland Park sits in the Central Corn Belt Plains — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Highland Parklydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Highland Park's 7,830 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 Highland Park's 7,830 acreswhy one lot differs from the next →
- Which side of Highland Park you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 7,830 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.4 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 Highland Park-wide figureread your own land →