Mount Olive, 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.
Well-matched crops include cabbage, hazelnut, 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 Mount Olive, 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 Mount Olive 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 Mount Olive — soil, climate, flood, and parcel records. How we handle your address.
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Mount Olive — the short answer
Mount Olive, Illinois: USDA zone 6b, about 217 days between hard freezes, across 738 acres of city.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 30
- 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
- ~217
- NOAA 1991–2020 Climate Normals, 28°F — this town
- City area
- 738 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 Mount Olive's average, not your lot's — a low corner or a tree line moves it. Against Mount Olive's 217-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Mount Olive
Each reading below is measured for Mount Olive itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredMount Olive runs about 217 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
MeasuredMount Olive 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 Mount Olive is in
Mount Olive sits in the Interior River Valleys and Hills — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Mount Olive's own centroid rather than borrowed from Macoupin County.
What Grows in Mount Olive
Every plant below cleared Mount Olive's own zone 6b and its 217-day season. Each card opens that plant's Illinois profile. How we score.
Is it too late to plant in Mount Olive?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Mar 2; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 30 (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. 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 Mount Olive
Closest first, within ~10 miles of Mount Olive. Listing isn't leaking, and distance isn't exposure.
- Mt. Olive Enterprises, LLC d/b/a Mt Olive ClarkUnderground Storage Tanks · 250 ft
- Mt. Olive ServiceUnderground Storage Tanks · 350 ft
- Oltman & CoUnderground Storage Tanks · 400 ft
- Bolch 61Underground Storage Tanks · 400 ft
- Bus GarageUnderground Storage Tanks · 400 ft
- Jubelt Variety Bakeries IncUnderground Storage Tanks · 400 ft
- Hagerman EarlUnderground Storage Tanks · 700 ft
- Jeep Niehaus & Sons LLCUnderground Storage Tanks · 1200 ft
- THE MENNEL MILLING COMPANY OF ILLINOISToxics Release Inventory · 1700 ft
- RSB Fuels, Inc.Underground Storage Tanks · 2200 ft
- Soulsby SerUnderground Storage Tanks · 2200 ft
- DOLLAR GENERAL STORE 7372Brownfields · 2200 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Mount Olive'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 Mount Olive.
Total Sites
192
within ~10 miles of Mount Olive
Risk Level
Elevated
Highest-severity
1 Superfund site (none NPL-listed)
Sources Checked
within ~10 miles of Mount Olive
Severity Distribution
within ~10 miles of Mount Olive
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Mount Olive, two things run higher than the national average within ~10 miles of Mount Olive — PFAS (4 sites) and CAFO (3 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
CAFO: CAFOs pose a different contamination profile than chemical sources.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Check your specific parcel in Mount Olive
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 Mount Olive average
Your land is one point inside Mount Olive
Everything above resolves to Mount Olive as a whole — one PHZM band and one 28°F frost record, read across 738 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 Mount Olive Average
Mount Olive Average
- ●USDA Zones 6b, averaged across Mount Olive
- ●One soil character for all of Mount Olive
- ●Frost dates read at Mount Olive's scale: Mar 30 to Nov 2
YOUR Parcel
- ✓Your exact zone, not Mount Olive's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Mount Olive
Pull a site-specific report for your exact address in Mount Olive, Illinois — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Mount Olive averages can't show:
We read public map data around Mount Olive — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Mount Olive average
How we know this about Mount Olive
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 Mount Olive’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 Mount Olive
When does frost risk typically end in Mount Olive?
The last hard freeze (28°F) in Mount Olive typically lands around Mar 30, 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 20.
When is the first frost in Mount Olive?
The first hard freeze (28°F) in Mount Olive 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 217 days after the spring freeze cleared.
How long is the growing season in Mount Olive?
Measured between 28°F hard freezes, Mount Olive sees about 217 frost-free days — roughly Mar 30 through Nov 2, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 20 to Oct 19, about 182 days.
Is the soil safe to grow vegetables in Mount Olive?
The federal record around Mount Olive is a meaningful one — 192 documented sites, mostly Underground Storage Tanks entries (128), 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 Mount Olive?
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 Mount Olive's scale — its 6b band and its 217-day season. Your yard writes its own version of Mount Olive'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 Mount Olive’s own scale
6 of the readings below were taken at Mount Olive's own scale — its own ~217-day season between 28°F freezes, the 738 acres it covers and 192 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Mount Olive's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Mount Olive's own 28°F hard-freeze dates, about Mar 30 and Nov 2 and the ~217-day span between themNOAA 1991–2020 Climate Normals
- 192 documented contamination sites on the federal record near Mount Olive, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
- Mount Olive's boundary and the 738 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~217-day seasonGrowable Ground crop-matching engine
- The ecoregion at Mount Olive'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 Mount Olive's 738 acres read through its county's SSURGO summaryfrom Macoupin County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Macoupin 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 Macoupin County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Mount Olive's 738 acreswhy one lot differs from the next →
- Which side of Mount Olive you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 738 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 Mount Olive-wide figureread your own land →
More in Illinois
Wider growing context
What grows across IllinoisMount Olive sits outside our named growing regions, so Illinois as a whole is its closest context here.
Nearby growing guides