Corydon, Indiana, sits in USDA hardiness zone 7a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
Crops well matched to these conditions include cabbage, hazelnut, california poppy, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Even in Corydon, 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 Corydon 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 Corydon — soil, climate, flood, and parcel records. How we handle your address.
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Corydon — the short answer
Corydon, Indiana: USDA zone 7a, about 224 days between hard freezes, across 1K acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 29
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 8
- 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 7a is Corydon's average, not your lot's — a low corner or a tree line moves it. Against Corydon's 224-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Corydon
Each reading below is measured for Corydon itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredCorydon 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
MeasuredCorydon 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 Corydon is in
Corydon sits in the Interior Plateau — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Corydon's own centroid rather than borrowed from Harrison County.
What Grows in Corydon
Every plant below cleared Corydon's own zone 7a and its 224-day season. Each card opens that plant's Indiana profile. How we score.
Is it too late to plant in Corydon?
Almost never — the real question is what to plant next. Cool-season crops can go in from around Mar 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 29 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 8 — 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 Corydon
Survey cells within 31 miles of Corydon checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 74 miles off. What to watch for.
What's on the federal record near Corydon
Closest first, within ~10 miles of Corydon. Listing isn't leaking, and distance isn't exposure.
- KINTNER STANDARD SERVICEUnderground Storage Tanks · 550 ft
- LOUISVILLE NEW ALBANY AND CORYDON RR COBrownfields · 750 ft
- CORYDON TOWN HALLUnderground Storage Tanks · 850 ft
- KELLER MANUFACTURING COMPANY INCORPORATEDUnderground Storage Tanks · 850 ft
- BULK PLANT 008Underground Storage Tanks · 900 ft
- CITGO 204Underground Storage Tanks · 950 ft
- KELLER MANUFACTURING COMPANY INCORPORATEDToxics Release Inventory · 1000 ft
- CONVENIENT MARKET & DELIUnderground Storage Tanks · 1200 ft
- MATTINGLY ICE HOUSEUnderground Storage Tanks · 1300 ft
- BROWN EQUIPMENT DISTRIBUTORSUnderground Storage Tanks · 1700 ft
- FURTHERING YOUTH INC GERDON YOUTH CTRBrownfields · 2200 ft
- MONROE OIL CORPORATION BULK PLANTUnderground Storage Tanks · 2500 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Corydon'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 Corydon.
Total Sites
107
within ~10 miles of Corydon
Risk Level
Moderate
Highest-severity
10 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of Corydon
Severity Distribution
within ~10 miles of Corydon
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Corydon, two things run higher than the national average within ~10 miles of Corydon — PFAS (4 sites) and Toxics Release Inventory (10 sites). That's not a problem with your land — it's information about it.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Check your specific parcel in Corydon
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 Corydon average
Your land is one point inside Corydon
Everything above resolves to Corydon 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 Corydon Average
Corydon Average
- ●USDA Zones 7a, averaged across Corydon
- ●One soil character for all of Corydon
- ●Frost dates read at Corydon's scale: Mar 29 to Nov 8
YOUR Parcel
- ✓Your exact zone, not Corydon's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Corydon
Pull a site-specific report for your exact address in Corydon, Indiana — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Corydon averages can't show:
We read public map data around Corydon — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Corydon average
How we know this about Corydon
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 Corydon’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 Corydon
When does frost risk typically end in Corydon?
The last hard freeze (28°F) in Corydon typically lands around Mar 29, 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 19.
When is the first frost in Corydon?
The first hard freeze (28°F) in Corydon typically arrives around Nov 8, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 25, so the watching starts about Oct 9 — about 224 days after the spring freeze cleared.
How long is the growing season in Corydon?
Measured between 28°F hard freezes, Corydon sees about 224 frost-free days — roughly Mar 29 through Nov 8, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 19 to Oct 25, about 189 days.
Is the soil safe to grow vegetables in Corydon?
The federal record around Corydon shows 107 documented sites, mostly Underground Storage Tanks entries (76), the nearest Underground Storage Tanks record about 0.1 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 Corydon?
From about Oct 9 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 8 (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 8. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Corydon's scale — its 7a band and its 224-day season. Your yard writes its own version of Corydon'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 Corydon’s own scale
7 of the readings below were taken at Corydon's own scale — its own ~224-day season between 28°F freezes, the 1,057 acres it covers and 107 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Corydon's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Corydon's own 28°F hard-freeze dates, about Mar 29 and Nov 8 and the ~224-day span between themNOAA 1991–2020 Climate Normals
- 107 documented contamination sites on the federal record near Corydon, the closest Underground Storage Tanks record about 0.1 miles out from the town centreFederal environmental registers
- Corydon's boundary and the 1,057 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~224-day seasonGrowable Ground crop-matching engine
- The ecoregion at Corydon's own centroid, the Interior PlateauUS EPA Level III Ecoregions
- Lanternfly survey cells around Corydon 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 Corydon's 1,057 acres read through its county's SSURGO summaryfrom Harrison County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Harrison County
- The growing challenges every Indiana grower plans around — written at state scale, so they stay on the state guidefrom Indiana
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Harrison County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Corydon's 1,057 acreswhy one lot differs from the next →
- Which side of Corydon you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,057 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks 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 Corydon-wide figureread your own land →