Okawville, Illinois, sits in USDA hardiness zone 6b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
A short list that earns its place here — cabbage, hazelnut, lavender, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Even in Okawville, 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 Okawville 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 Okawville — soil, climate, flood, and parcel records. How we handle your address.
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Okawville — the short answer
Okawville, Illinois: USDA zone 6b, about 224 days between hard freezes, across 1K acres of town.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 26
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 5
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~224
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 1K 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 6b is Okawville's average, not your lot's — a low corner or a tree line moves it. Against Okawville's 224-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Okawville
Each reading below is measured for Okawville itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredOkawville runs about 224 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
MeasuredOkawville sits in USDA hardiness zone 6b.
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 Okawville is in
Okawville sits in the Interior River Valleys and Hills — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Okawville's own centroid rather than borrowed from Washington County.
What Grows in Okawville
Every plant below cleared Okawville's own zone 6b and its 224-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Okawville?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Feb 26; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 26 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 5 — 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.
What's on the federal record near Okawville
Closest first, within ~10 miles of Okawville. Listing isn't leaking, and distance isn't exposure.
- Reichmann BrosUnderground Storage Tanks · 500 ft
- St Barbaras Catholic ChurchUnderground Storage Tanks · 1100 ft
- Haier Plbg & Htg IncUnderground Storage Tanks · 1400 ft
- Circle K #1350Underground Storage Tanks · 1600 ft
- Streuter Chevrolet IncUnderground Storage Tanks · 1600 ft
- Road Ranger #157Underground Storage Tanks · 0.8 mi
- DOLLAR GENERAL STORE 9637Brownfields · 0.8 mi
- ROAD RANGERBrownfields · 0.8 mi
- ELM FARMSCAFO · 2.2 mi
- 1S 4W- 4.7b1Nitrate · 2.3 mi
- Segelhorst GarageUnderground Storage Tanks · 3.6 mi
- Okawville Equipment CoUnderground Storage Tanks · 4.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Okawville'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 Okawville.
Total Sites
64
within ~10 miles of Okawville
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Okawville
Severity Distribution
within ~10 miles of Okawville
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Okawville, CAFO runs higher than the national average — 11 sites within ~10 miles of Okawville. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Check your specific parcel in Okawville
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 Okawville average
Your land is one point inside Okawville
Everything above resolves to Okawville as a whole — one PHZM band and one 28°F frost record, read across 1K 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 Okawville Average
Okawville Average
- ●USDA Zones 6b, averaged across Okawville
- ●One soil character for all of Okawville
- ●Frost dates read at Okawville's scale: Mar 26 to Nov 5
YOUR Parcel
- ✓Your exact zone, not Okawville's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Okawville
Pull a site-specific report for your exact address in Okawville, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Okawville averages can't show:
We read public map data around Okawville — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Okawville average
How we know this about Okawville
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 Okawville’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 Okawville
When does frost risk typically end in Okawville?
The last hard freeze (28°F) in Okawville typically lands around Mar 26, 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 16.
When is the first frost in Okawville?
The first hard freeze (28°F) in Okawville typically arrives around Nov 5, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 22, so the watching starts about Oct 6 — about 224 days after the spring freeze cleared.
How long is the growing season in Okawville?
Measured between 28°F hard freezes, Okawville sees about 224 frost-free days — roughly Mar 26 through Nov 5, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 16 to Oct 22, about 189 days.
Is the soil safe to grow vegetables in Okawville?
The federal record around Okawville is a meaningful one — 64 documented sites, mostly Underground Storage Tanks entries (37), 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 Okawville?
From about Oct 6 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 5 (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 5. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Okawville's scale — its 6b band and its 224-day season. Your yard writes its own version of Okawville'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 Okawville’s own scale
6 of the readings below were taken at Okawville's own scale — its own ~224-day season between 28°F freezes, the 1,296 acres it covers and 64 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Okawville's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Okawville's own 28°F hard-freeze dates, about Mar 26 and Nov 5 and the ~224-day span between themNOAA 1991–2020 Climate Normals
- 64 documented contamination sites on the federal record near Okawville, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Okawville's boundary and the 1,296 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~224-day seasonGrowable Ground crop-matching engine
- The ecoregion at Okawville's own centroid, the Interior River Valleys and HillsUS EPA Level III Ecoregions
Inherited from a wider read
- Soil character — no town-scale survey exists, so Okawville's 1,296 acres read through its county's SSURGO summaryfrom Washington County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Washington 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 Washington County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Okawville's 1,296 acreswhy one lot differs from the next →
- Which side of Okawville you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,296 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 Okawville-wide figureread your own land →
More in Illinois
Wider growing context
What grows across IllinoisOkawville sits outside our named growing regions, so Illinois as a whole is its closest context here.
Nearby growing guides