Oblong, Illinois, sits in USDA hardiness zone 6b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Among the crops suited to this profile: cabbage, hazelnut, lavender, and collard greens. The site-level story — soil, sun, drainage — decides the rest.
Even in Oblong, 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 Oblong 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 Oblong — soil, climate, flood, and parcel records. How we handle your address.
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Oblong — the short answer
Oblong, Illinois: USDA zone 6b, about 216 days between hard freezes, across 695 acres of town.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 1
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 3
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~216
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 695 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 Oblong's average, not your lot's — a low corner or a tree line moves it. Against Oblong's 216-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Oblong
Each reading below is measured for Oblong itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredOblong runs about 216 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
MeasuredOblong 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 Oblong is in
Oblong sits in the Interior River Valleys and Hills — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Oblong's own centroid rather than borrowed from Crawford County.
What Grows in Oblong
Every plant below cleared Oblong's own zone 6b and its 216-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Oblong?
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 4; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 1 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 3 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
Documented around Oblong
Survey cells within 31 miles of Oblong checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 145 miles off. What to watch for.
What's on the federal record near Oblong
Closest first, within ~10 miles of Oblong. Listing isn't leaking, and distance isn't exposure.
- Blue Truck Trading Company, LLCUnderground Storage Tanks · 200 ft
- Freedom Oil CompanyUnderground Storage Tanks · 400 ft
- Neeley Oil Co.Underground Storage Tanks · 450 ft
- Rains Oil CoUnderground Storage Tanks · 950 ft
- KrickdavidUnderground Storage Tanks · 950 ft
- Bellair Oil Co.Underground Storage Tanks · 950 ft
- Thompson Chemical IncUnderground Storage Tanks · 950 ft
- Sparks & SonsUnderground Storage Tanks · 950 ft
- MacDonell Co of Lima, Inc.Underground Storage Tanks · 950 ft
- Lincoln Trail Fs IncUnderground Storage Tanks · 950 ft
- Jg Mcknight ToolhouseUnderground Storage Tanks · 950 ft
- Ikemire FrancesUnderground Storage Tanks · 950 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Oblong'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 Oblong.
Total Sites
100
within ~10 miles of Oblong
Risk Level
Moderate
Highest-severity
5 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Oblong
Severity Distribution
within ~10 miles of Oblong
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Oblong, Underground Storage Tanks runs higher than the national average — 76 sites within ~10 miles of Oblong. 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 Oblong
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 Oblong average
Your land is one point inside Oblong
Everything above resolves to Oblong as a whole — one PHZM band and one 28°F frost record, read across 695 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 Oblong Average
Oblong Average
- ●USDA Zones 6b, averaged across Oblong
- ●One soil character for all of Oblong
- ●Frost dates read at Oblong's scale: Apr 1 to Nov 3
YOUR Parcel
- ✓Your exact zone, not Oblong's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Oblong
Pull a site-specific report for your exact address in Oblong, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Oblong averages can't show:
We read public map data around Oblong — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Oblong average
How we know this about Oblong
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 Oblong’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 Oblong
When does frost risk typically end in Oblong?
The last hard freeze (28°F) in Oblong typically lands around Apr 1, 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 22.
When is the first frost in Oblong?
The first hard freeze (28°F) in Oblong typically arrives around Nov 3, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 20, so the watching starts about Oct 4 — about 216 days after the spring freeze cleared.
How long is the growing season in Oblong?
Measured between 28°F hard freezes, Oblong sees about 216 frost-free days — roughly Apr 1 through Nov 3, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 22 to Oct 20, about 181 days.
Is the soil safe to grow vegetables in Oblong?
The federal record around Oblong shows 100 documented sites, mostly Underground Storage Tanks entries (76), 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 Oblong?
From about Oct 4 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 3 (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 3. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Oblong's scale — its 6b band and its 216-day season. Your yard writes its own version of Oblong'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 Oblong’s own scale
7 of the readings below were taken at Oblong's own scale — its own ~216-day season between 28°F freezes, the 695 acres it covers and 100 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Oblong's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Oblong's own 28°F hard-freeze dates, about Apr 1 and Nov 3 and the ~216-day span between themNOAA 1991–2020 Climate Normals
- 100 documented contamination sites on the federal record near Oblong, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Oblong's boundary and the 695 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~216-day seasonGrowable Ground crop-matching engine
- The ecoregion at Oblong's own centroid, the Interior River Valleys and HillsUS EPA Level III Ecoregions
- Lanternfly survey cells around Oblong 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 Oblong's 695 acres read through its county's SSURGO summaryfrom Crawford County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Crawford 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 Crawford County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Oblong's 695 acreswhy one lot differs from the next →
- Which side of Oblong you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 695 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 Oblong-wide figureread your own land →
More in Illinois
Wider growing context
What grows across IllinoisOblong sits outside our named growing regions, so Illinois as a whole is its closest context here.
Nearby growing guides