Onton, Kentucky, sits in USDA hardiness zone 7a — a zone band wide enough that plant choice, not possibility, is the interesting question.
Well-matched crops include cabbage, hazelnut, california poppy, 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 Onton, 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 Onton 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 Onton — soil, climate, flood, and parcel records. How we handle your address.
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Onton — the short answer
Onton, Kentucky: USDA zone 7a, about 232 days between hard freezes, across 528 acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 23
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 10
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~232
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 528 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 7a is Onton's average, not your lot's — a low corner or a tree line moves it. Against Onton's 232-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Onton
Each reading below is measured for Onton itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredOnton runs about 232 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
MeasuredOnton sits in USDA hardiness zone 7a.
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 Onton is in
Onton sits in the Interior River Valleys and Hills — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Onton's own centroid rather than borrowed from Webster County.
What Grows in Onton
Every plant below cleared Onton's own zone 7a and its 232-day season. Each card opens that plant's Kentucky profile. How we score.
Is it too late to plant in Onton?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Feb 23; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 23 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 10 — 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.
Documented around Onton
Survey cells within 31 miles of Onton checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 104 miles off. What to watch for.
What's on the federal record near Onton
Closest first, within ~10 miles of Onton. Listing isn't leaking, and distance isn't exposure.
- G10C0013Nitrate · 0.5 mi
- Jackson Garage & RestaurantUnderground Storage Tanks · 0.6 mi
- Ward Implement CoUnderground Storage Tanks · 4.2 mi
- Gte Spring Elba JunctionUnderground Storage Tanks · 4.4 mi
- Young PropertyUnderground Storage Tanks · 4.4 mi
- BGs Foodmart IncUnderground Storage Tanks · 4.4 mi
- TYSON FOODS - HATCHERYBrownfields · 4.4 mi
- Smith Super SaverUnderground Storage Tanks · 4.4 mi
- KY Dept Of TransporationUnderground Storage Tanks · 4.4 mi
- G9D0029Nitrate · 4.5 mi
- FCD LLC SEBREE DOCKBrownfields · 4.6 mi
- G10C0014Nitrate · 4.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Onton'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 Onton.
Total Sites
93
within ~10 miles of Onton
Risk Level
Moderate
Highest-severity
7 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Onton
Severity Distribution
within ~10 miles of Onton
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Onton, Toxics Release Inventory runs higher than the national average — 7 sites within ~10 miles of Onton. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Onton
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 Onton average
Your land is one point inside Onton
Everything above resolves to Onton as a whole — one PHZM band and one 28°F frost record, read across 528 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 Onton Average
Onton Average
- ●USDA Zones 7a, averaged across Onton
- ●One soil character for all of Onton
- ●Frost dates read at Onton's scale: Mar 23 to Nov 10
YOUR Parcel
- ✓Your exact zone, not Onton's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Onton
Pull a site-specific report for your exact address in Onton, Kentucky — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Onton averages can't show:
We read public map data around Onton — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Onton average
How we know this about Onton
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 Onton’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 Onton
When does frost risk typically end in Onton?
The last hard freeze (28°F) in Onton typically lands around Mar 23, 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 13.
When is the first frost in Onton?
The first hard freeze (28°F) in Onton typically arrives around Nov 10, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 27, so the watching starts about Oct 11 — about 232 days after the spring freeze cleared.
How long is the growing season in Onton?
Measured between 28°F hard freezes, Onton sees about 232 frost-free days — roughly Mar 23 through Nov 10, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 13 to Oct 27, about 197 days.
Is the soil safe to grow vegetables in Onton?
The federal record around Onton shows 93 documented sites, mostly Underground Storage Tanks entries (51), the nearest Nitrate record about 0.5 miles 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 Onton?
From about Oct 11 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 10 (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 10. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Onton's scale — its 7a band and its 232-day season. Your yard writes its own version of Onton'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 Onton’s own scale
7 of the readings below were taken at Onton's own scale — its own ~232-day season between 28°F freezes, the 528 acres it covers and 93 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Onton's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Onton's own 28°F hard-freeze dates, about Mar 23 and Nov 10 and the ~232-day span between themNOAA 1991–2020 Climate Normals
- 93 documented contamination sites on the federal record near Onton, the closest Nitrate record about 0.5 miles out from the town centreFederal environmental registers
- Onton's boundary and the 528 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~232-day seasonGrowable Ground crop-matching engine
- The ecoregion at Onton's own centroid, the Interior River Valleys and HillsUS EPA Level III Ecoregions
- Lanternfly survey cells around Onton 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 Onton's 528 acres read through its county's SSURGO summaryfrom Webster County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Webster County
- The growing challenges every Kentucky grower plans around — written at state scale, so they stay on the state guidefrom Kentucky
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Webster County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Onton's 528 acreswhy one lot differs from the next →
- Which side of Onton you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 528 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.5 miles 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 Onton-wide figureread your own land →
More in Kentucky
Wider growing context
What grows across KentuckyOnton sits outside our named growing regions, so Kentucky as a whole is its closest context here.
Nearby growing guides