Radnor, Ohio, 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.
Crops well matched to these conditions include cabbage, hazelnut, lavender, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Even in Radnor, 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 Radnor 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 Radnor — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Radnor — the short answer
Radnor, Ohio: USDA zone 6b, about 210 days between hard freezes, across 461 acres of town.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 8
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 4
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~210
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 461 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 Radnor's average, not your lot's — a low corner or a tree line moves it. Against Radnor's 210-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Radnor
Each reading below is measured for Radnor itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredRadnor runs about 210 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
MeasuredRadnor 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 Radnor is in
Radnor sits in the Eastern Corn Belt Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Radnor's own centroid rather than borrowed from Delaware County.
What Grows in Radnor
Every plant below cleared Radnor's own zone 6b and its 210-day season. Each card opens that plant's Ohio profile. How we score.
Is it too late to plant in Radnor?
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 11; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 8 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 4 — long-season crops need about 90 days of runway, quick greens only 30. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.
Documented around Radnor
Spotted lanternfly documented 27 miles from Radnor, first recorded 2022. What to watch for.
What's on the federal record near Radnor
Closest first, within ~10 miles of Radnor. Listing isn't leaking, and distance isn't exposure.
- 3D AUTOMOTIVE INCBrownfields · 750 ft
- PAUL COONFAREUnderground Storage Tanks · 900 ft
- RADNOR REPAIRUnderground Storage Tanks · 1500 ft
- BUCKEYE VALLEY LOCAL SCHOOLSUnderground Storage Tanks · 1900 ft
- MENNEL MILLING - RADNORBrownfields · 0.6 mi
- PENRY STONE CO.Underground Storage Tanks · 1.6 mi
- CECIL ROBINSONUnderground Storage Tanks · 1.6 mi
- RONALD RHOADESUnderground Storage Tanks · 2.5 mi
- BUCKEYE VALLEY LOCAL MIDDLE SCHOOLBrownfields · 3.8 mi
- US ARMY CORPS OF ENGINEERS - DELAWARE LAKEBrownfields · 4.2 mi
- CENTURYLINKUnderground Storage Tanks · 4.3 mi
- CERTIFIED OIL CO. #150Underground Storage Tanks · 4.3 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Radnor'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 Radnor.
Total Sites
259
within ~10 miles of Radnor
Risk Level
Elevated
Highest-severity
3 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Radnor
Severity Distribution
within ~10 miles of Radnor
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Radnor, Toxics Release Inventory runs higher than the national average — 23 sites within ~10 miles of Radnor. Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
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 Radnor
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 Radnor average
Your land is one point inside Radnor
Everything above resolves to Radnor as a whole — one PHZM band and one 28°F frost record, read across 461 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 Radnor Average
Radnor Average
- ●USDA Zones 6b, averaged across Radnor
- ●One soil character for all of Radnor
- ●Frost dates read at Radnor's scale: Apr 8 to Nov 4
YOUR Parcel
- ✓Your exact zone, not Radnor's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Radnor
Pull a site-specific report for your exact address in Radnor, Ohio — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Radnor averages can't show:
We read public map data around Radnor — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Radnor average
How we know this about Radnor
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 Radnor’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 Radnor
When does frost risk typically end in Radnor?
The last hard freeze (28°F) in Radnor typically lands around Apr 8, 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 29.
When is the first frost in Radnor?
The first hard freeze (28°F) in Radnor typically arrives around Nov 4, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 21, so the watching starts about Oct 5 — about 210 days after the spring freeze cleared.
How long is the growing season in Radnor?
Measured between 28°F hard freezes, Radnor sees about 210 frost-free days — roughly Apr 8 through Nov 4, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 29 to Oct 21, about 175 days.
Is the soil safe to grow vegetables in Radnor?
The federal record around Radnor is a meaningful one — 259 documented sites, mostly Underground Storage Tanks entries (112), the nearest Brownfields record about 0.1 miles 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 Radnor?
From about Oct 5 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 4 (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 4. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Radnor's scale — its 6b band and its 210-day season. Your yard writes its own version of Radnor'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 Radnor’s own scale
7 of the readings below were taken at Radnor's own scale — its own ~210-day season between 28°F freezes, the 461 acres it covers and 259 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Radnor's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Radnor's own 28°F hard-freeze dates, about Apr 8 and Nov 4 and the ~210-day span between themNOAA 1991–2020 Climate Normals
- 259 documented contamination sites on the federal record near Radnor, the closest Brownfields record about 0.1 miles out from the town centreFederal environmental registers
- Radnor's boundary and the 461 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~210-day seasonGrowable Ground crop-matching engine
- The ecoregion at Radnor's own centroid, the Eastern Corn Belt PlainsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Radnorlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Radnor's 461 acres read through its county's SSURGO summaryfrom Delaware County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Delaware County
- The growing challenges every Ohio grower plans around — written at state scale, so they stay on the state guidefrom Ohio
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Delaware County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Radnor's 461 acreswhy one lot differs from the next →
- Which side of Radnor you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 461 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.1 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 Radnor-wide figureread your own land →
More in Ohio
Wider growing context
What grows across OhioRadnor sits outside our named growing regions, so Ohio as a whole is its closest context here.
Nearby growing guides