Alden, Illinois, sits in USDA hardiness zone 5b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Well-matched crops include cabbage, cranberry, lavender, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in Alden, 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 Alden 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 Alden — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Alden — the short answer
Alden, Illinois: USDA zone 5b, about 192 days between hard freezes, across 81 acres of town.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 14
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 23
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~192
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 81 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 Alden's average, not your lot's — a low corner or a tree line moves it. Against Alden's 192-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Alden
Each reading below is measured for Alden itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredAlden runs about 192 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
MeasuredAlden 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 Alden is in
Alden sits in the Southeastern Wisconsin Till Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Alden's own centroid rather than borrowed from McHenry County.
What Grows in Alden
Every plant below cleared Alden's own zone 5b and its 192-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Alden?
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 17; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 14 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 23 — 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.
What's on the federal record near Alden
Closest first, within ~10 miles of Alden. Listing isn't leaking, and distance isn't exposure.
- Alden Quick MartUnderground Storage Tanks · 300 ft
- Alden Township GarageUnderground Storage Tanks · 550 ft
- 46N6E-12.5d (HEBR-09-03)Nitrate · 2.4 mi
- 46N6E-08.46l (2-ALD-D)Nitrate · 2.4 mi
- AINGER FARMSCAFO · 2.5 mi
- 1N17E-32.6ENitrate · 3.1 mi
- 46N 6E-30.2aNitrate · 3.4 mi
- Walter Daniel RUnderground Storage Tanks · 3.9 mi
- NORTHERN FS INCUnderground Storage Tanks · 3.9 mi
- ZENDA LUMBER COMPANYUnderground Storage Tanks · 4.0 mi
- MELGES BOAT WORKS INCBrownfields · 4.1 mi
- WW-01/17E/28-0207Nitrate · 4.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Alden'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 Alden.
Total Sites
381
within ~10 miles of Alden
Risk Level
Elevated
Highest-severity
3 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Alden
Severity Distribution
within ~10 miles of Alden
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Alden, two things run higher than the national average within ~10 miles of Alden — PFAS (6 sites) and Toxics Release Inventory (27 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 Alden
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 Alden average
Your land is one point inside Alden
Everything above resolves to Alden as a whole — one PHZM band and one 28°F frost record, read across 81 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 Alden Average
Alden Average
- ●USDA Zones 5b, averaged across Alden
- ●One soil character for all of Alden
- ●Frost dates read at Alden's scale: Apr 14 to Oct 23
YOUR Parcel
- ✓Your exact zone, not Alden's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Alden
Pull a site-specific report for your exact address in Alden, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Alden averages can't show:
We read public map data around Alden — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Alden average
How we know this about Alden
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 Alden’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 Alden
When does frost risk typically end in Alden?
The last hard freeze (28°F) in Alden typically lands around Apr 14, 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 5.
When is the first frost in Alden?
The first hard freeze (28°F) in Alden typically arrives around Oct 23, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 9, so the watching starts about Sep 23 — about 192 days after the spring freeze cleared.
How long is the growing season in Alden?
Measured between 28°F hard freezes, Alden sees about 192 frost-free days — roughly Apr 14 through Oct 23, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 5 to Oct 9, about 157 days.
Is the soil safe to grow vegetables in Alden?
The federal record around Alden is a meaningful one — 381 documented sites, mostly Underground Storage Tanks entries (180), the nearest Underground Storage Tanks record under a tenth of a mile 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 Alden?
From about Sep 23 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 23 (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 23. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Alden's scale — its 5b band and its 192-day season. Your yard writes its own version of Alden'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 Alden’s own scale
6 of the readings below were taken at Alden's own scale — its own ~192-day season between 28°F freezes, the 81 acres it covers and 381 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Alden's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Alden's own 28°F hard-freeze dates, about Apr 14 and Oct 23 and the ~192-day span between themNOAA 1991–2020 Climate Normals
- 381 documented contamination sites on the federal record near Alden, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Alden's boundary and the 81 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~192-day seasonGrowable Ground crop-matching engine
- The ecoregion at Alden's own centroid, the Southeastern Wisconsin Till PlainsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Alden's 81 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 Alden's 81 acreswhy one lot differs from the next →
- Which side of Alden you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 81 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 Alden-wide figureread your own land →
More in Illinois
Wider growing context
What grows across IllinoisAlden sits outside our named growing regions, so Illinois as a whole is its closest context here.
Nearby growing guides