Donovan, Illinois, sits in USDA hardiness zone 5b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Among the crops suited to this profile: cabbage, cranberry, lavender, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Donovan, 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 Donovan 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 Donovan — soil, climate, flood, and parcel records. How we handle your address.
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Donovan — the short answer
Donovan, Illinois: USDA zone 5b, about 198 days between hard freezes, across 210 acres of town.
- USDA zone
- 5b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 10
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 25
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~198
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 210 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 Donovan's average, not your lot's — a low corner or a tree line moves it. Against Donovan's 198-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Donovan
Each reading below is measured for Donovan itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredDonovan runs about 198 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
MeasuredDonovan 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 Donovan is in
Donovan sits in the Central Corn Belt Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Donovan's own centroid rather than borrowed from Iroquois County.
What Grows in Donovan
Every plant below cleared Donovan's own zone 5b and its 198-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Donovan?
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 13; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 10 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 25 — long-season crops need about 90 days of runway, quick greens only 30. Late in the year the fall bench takes over — quick greens, radishes, and garlic that repays you next summer.
Documented around Donovan
Survey cells within 31 miles of Donovan checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 53 miles off. What to watch for.
What's on the federal record near Donovan
Closest first, within ~10 miles of Donovan. Listing isn't leaking, and distance isn't exposure.
- Hi-Grade Egg Producers & ProcessUnderground Storage Tanks · 450 ft
- Donovan Comm Unit 3 SchoolsUnderground Storage Tanks · 450 ft
- Clark Richard RUnderground Storage Tanks · 550 ft
- Beaver Twp Road DistUnderground Storage Tanks · 750 ft
- Kusman Gas StationUnderground Storage Tanks · 800 ft
- Hewson Ford SalesUnderground Storage Tanks · 800 ft
- Donovan Plumbing & Heating IncUnderground Storage Tanks · 800 ft
- Fertilizer PlantUnderground Storage Tanks · 1000 ft
- DONOVAN EGG FARMCAFO · 1.0 mi
- Strean GarageUnderground Storage Tanks · 4.1 mi
- C & C Auto SerUnderground Storage Tanks · 4.2 mi
- Concord Township Road DistUnderground Storage Tanks · 4.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Donovan'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 Donovan.
Total Sites
111
within ~10 miles of Donovan
Risk Level
Moderate
Highest-severity
3 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Donovan
Severity Distribution
within ~10 miles of Donovan
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Donovan, Underground Storage Tanks runs higher than the national average — 78 sites within ~10 miles of Donovan. That's not a problem with your land — it's information about it.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Donovan
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 Donovan average
Your land is one point inside Donovan
Everything above resolves to Donovan as a whole — one PHZM band and one 28°F frost record, read across 210 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 Donovan Average
Donovan Average
- ●USDA Zones 5b, averaged across Donovan
- ●One soil character for all of Donovan
- ●Frost dates read at Donovan's scale: Apr 10 to Oct 25
YOUR Parcel
- ✓Your exact zone, not Donovan's 5b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Donovan
Pull a site-specific report for your exact address in Donovan, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Donovan averages can't show:
We read public map data around Donovan — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Donovan average
How we know this about Donovan
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 Donovan’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 Donovan
When does frost risk typically end in Donovan?
The last hard freeze (28°F) in Donovan typically lands around Apr 10, 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 1.
When is the first frost in Donovan?
The first hard freeze (28°F) in Donovan typically arrives around Oct 25, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 11, so the watching starts about Sep 25 — about 198 days after the spring freeze cleared.
How long is the growing season in Donovan?
Measured between 28°F hard freezes, Donovan sees about 198 frost-free days — roughly Apr 10 through Oct 25, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 1 to Oct 11, about 163 days.
Is the soil safe to grow vegetables in Donovan?
The federal record around Donovan shows 111 documented sites, mostly Underground Storage Tanks entries (78), the nearest Underground Storage Tanks record under a tenth of a mile out — a typical footprint for a growing area, and proximity to a documented site is information, not a diagnosis of any one yard. It's worth seeing which recorded sites sit closest to where you grow, and testing the soil before new food beds near any of them.
How do I protect my plants from frost in Donovan?
From about Sep 25 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 25 (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 25. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Donovan's scale — its 5b band and its 198-day season. Your yard writes its own version of Donovan'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 Donovan’s own scale
7 of the readings below were taken at Donovan's own scale — its own ~198-day season between 28°F freezes, the 210 acres it covers and 111 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Donovan's own USDA hardiness band, zones 5bUSDA PHZM 2023
- Donovan's own 28°F hard-freeze dates, about Apr 10 and Oct 25 and the ~198-day span between themNOAA 1991–2020 Climate Normals
- 111 documented contamination sites on the federal record near Donovan, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Donovan's boundary and the 210 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 5b and a ~198-day seasonGrowable Ground crop-matching engine
- The ecoregion at Donovan's own centroid, the Central Corn Belt PlainsUS EPA Level III Ecoregions
- Lanternfly survey cells around Donovan checked, none carrying a detectionlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Donovan's 210 acres read through its county's SSURGO summaryfrom Iroquois County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Iroquois 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 Iroquois County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Donovan's 210 acreswhy one lot differs from the next →
- Which side of Donovan you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 210 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 Donovan-wide figureread your own land →
More in Illinois
Wider growing context
What grows across IllinoisDonovan sits outside our named growing regions, so Illinois as a whole is its closest context here.
Nearby growing guides