South Mount Vernon, Ohio, sits in USDA hardiness zone 6a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Reliable performers under these conditions include cabbage, hazelnut, lavender, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in South Mount Vernon, 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 South Mount Vernon 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 South Mount Vernon — soil, climate, flood, and parcel records. How we handle your address.
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South Mount Vernon — the short answer
South Mount Vernon, Ohio: USDA zone 6a, about 190 days between hard freezes, across 319 acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 17
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 24
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~190
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 319 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 6a is South Mount Vernon's average, not your lot's — a low corner or a tree line moves it. Against South Mount Vernon's 190-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in South Mount Vernon
Each reading below is measured for South Mount Vernon itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSouth Mount Vernon runs about 190 days between hard freezes — a moderate growing season.
There is room for the full run of cool-season crops plus a warm-season main crop, but the calendar is tight enough that a late spring or early fall frost still decides how much finishes.
Time warm-season transplants to your last hard freeze, and a few weeks of season extension turns a near-miss harvest into a sure one.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredSouth Mount Vernon sits in USDA hardiness zone 6a.
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 South Mount Vernon is in
South Mount Vernon sits in the Erie Drift Plain — EPA Level III, inside the wider Eastern Temperate Forests. That is read at South Mount Vernon's own centroid rather than borrowed from Knox County.
What Grows in South Mount Vernon
Every plant below cleared South Mount Vernon's own zone 6a and its 190-day season. Each card opens that plant's Ohio profile. How we score.
Is it too late to plant in South Mount Vernon?
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 20; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 17 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 24 — long-season crops need about 90 days of runway, quick greens only 30. As the window narrows, the plantings just get faster — fall brassicas, then greens, then garlic to finish.
Documented around South Mount Vernon
Survey cells within 31 miles of South Mount Vernon checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 35 miles off. What to watch for.
What's on the federal record near South Mount Vernon
Closest first, within ~10 miles of South Mount Vernon. Listing isn't leaking, and distance isn't exposure.
- OHIO DEPT OF TRANSPORTATION GARAGEBrownfields · 1600 ft
- ODOT KNOX COUNTY GARAGEUnderground Storage Tanks · 1600 ft
- SUPERIOR QUALITY BODY SHOPBrownfields · 1700 ft
- FARMERS FORDUnderground Storage Tanks · 1800 ft
- HARCOURT ROAD GRAB N DASHUnderground Storage Tanks · 1800 ft
- BEEHIVE INDUSTRIES LLCBrownfields · 1800 ft
- ON SPEC FUELSUnderground Storage Tanks · 2000 ft
- MOUNT VERNON CITY SCHOOLSUnderground Storage Tanks · 2500 ft
- CAPITAL CITY OIL, INCBrownfields · 2500 ft
- C. L. RICHERT TRUCKING CO., INC.Underground Storage Tanks · 0.7 mi
- KNOX COUNTY ENGINEERUnderground Storage Tanks · 0.7 mi
- DWT LOGISTICS LLCBrownfields · 0.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from South Mount Vernon'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 South Mount Vernon.
Total Sites
175
within ~10 miles of South Mount Vernon
Risk Level
Moderate
Highest-severity
10 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of South Mount Vernon
Severity Distribution
within ~10 miles of South Mount Vernon
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •TRI facilities report what they release. Check the wind — downwind beds catch more of it.
Check your specific parcel in South Mount Vernon
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 South Mount Vernon average
Your land is one point inside South Mount Vernon
Everything above resolves to South Mount Vernon as a whole — one PHZM band and one 28°F frost record, read across 319 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 South Mount Vernon Average
South Mount Vernon Average
- ●USDA Zones 6a, averaged across South Mount Vernon
- ●One soil character for all of South Mount Vernon
- ●Frost dates read at South Mount Vernon's scale: Apr 17 to Oct 24
YOUR Parcel
- ✓Your exact zone, not South Mount Vernon's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in South Mount Vernon
Pull a site-specific report for your exact address in South Mount Vernon, Ohio — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that South Mount Vernon averages can't show:
We read public map data around South Mount Vernon — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the South Mount Vernon average
How we know this about South Mount Vernon
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 South Mount Vernon’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 South Mount Vernon
When does frost risk typically end in South Mount Vernon?
The last hard freeze (28°F) in South Mount Vernon typically lands around Apr 17, 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 May 8.
When is the first frost in South Mount Vernon?
The first hard freeze (28°F) in South Mount Vernon typically arrives around Oct 24, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 10, so the watching starts about Sep 24 — about 190 days after the spring freeze cleared.
How long is the growing season in South Mount Vernon?
Measured between 28°F hard freezes, South Mount Vernon sees about 190 frost-free days — roughly Apr 17 through Oct 24, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 8 to Oct 10, about 155 days.
Is the soil safe to grow vegetables in South Mount Vernon?
The federal record around South Mount Vernon shows 175 documented sites, mostly Underground Storage Tanks entries (102), the nearest Brownfields record about 0.3 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 South Mount Vernon?
From about Sep 24 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 Oct 24 (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 Oct 24. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at South Mount Vernon's scale — its 6a band and its 190-day season. Your yard writes its own version of South Mount Vernon'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 South Mount Vernon’s own scale
7 of the readings below were taken at South Mount Vernon's own scale — its own ~190-day season between 28°F freezes, the 319 acres it covers and 175 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- South Mount Vernon's own USDA hardiness band, zones 6aUSDA PHZM 2023
- South Mount Vernon's own 28°F hard-freeze dates, about Apr 17 and Oct 24 and the ~190-day span between themNOAA 1991–2020 Climate Normals
- 175 documented contamination sites on the federal record near South Mount Vernon, the closest Brownfields record about 0.3 miles out from the town centreFederal environmental registers
- South Mount Vernon's boundary and the 319 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~190-day seasonGrowable Ground crop-matching engine
- The ecoregion at South Mount Vernon's own centroid, the Erie Drift PlainUS EPA Level III Ecoregions
- Lanternfly survey cells around South Mount Vernon 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 South Mount Vernon's 319 acres read through its county's SSURGO summaryfrom Knox County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Knox 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 Knox County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among South Mount Vernon's 319 acreswhy one lot differs from the next →
- Which side of South Mount Vernon you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 319 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.3 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 South Mount Vernon-wide figureread your own land →
More in Ohio
Wider growing context
What grows across OhioSouth Mount Vernon sits outside our named growing regions, so Ohio as a whole is its closest context here.
Nearby growing guides