What Grows in Flat Rock, Ohio

USDA Zones 6a · 136 acres

Flat Rock, Ohio, sits in USDA hardiness zone 6a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.

A short list that earns its place here — cabbage, hazelnut, lavender, and collard greens — with any one site's soil, sun, and drainage making the final cut.

Score your parcel · free

Even in Flat Rock, 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 Flat Rock 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 Flat Rock — soil, climate, flood, and parcel records. How we handle your address.

No card required · your full report in seconds

Flat Rock — the short answer

Flat Rock, Ohio: USDA zone 6a, about 203 days between hard freezes, across 136 acres of town.

USDA zone
6a
USDA PHZM 2023
Last hard freeze (28°F)
Apr 15
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
~203
NOAA 1991–2020 Climate Normals, 28°F — this town
Town area
136 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

6a6a
3a (Cold)13b (Hot)

Zone 6a is Flat Rock's average, not your lot's — a low corner or a tree line moves it. Against Flat Rock's 203-day season, see what your own ground reads.

Soil varies lot by lot — soil types explained.

What this means for growing in Flat Rock

Each reading below is measured for Flat Rock itself — here is what it means for a garden here, and the move an experienced grower makes about it.

Season length

Measured

Flat Rock runs about 203 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

Measured

Flat Rock 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 Flat Rock is in

Flat Rock sits in the Huron/Erie Lake Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Flat Rock's own centroid rather than borrowed from Seneca County.

What that means for soil

What Grows in Flat Rock

Every plant below cleared Flat Rock's own zone 6a and its 203-day season. Each card opens that plant's Ohio profile. How we score.

cabbage, photograph
Growing cabbage in OhioZones 2–11Flat Rock's 6a — 4 zones of cold margin.
hazelnut, photograph
Ohio hazelnut guideZones 4–9Flat Rock's 6a — 2 zones of cold margin.
lavender, photograph
Lavender in OhioZones 5–8Flat Rock's 6a — 1 zone of cold margin.
collard greens, photograph
Collard greens: Ohio growing notesZones 2–11Flat Rock's 6a — 4 zones of cold margin.
blueberry, photograph
Growing blueberry in OhioZones 3–8Flat Rock's 6a — 3 zones of cold margin.
California poppy, photograph
Ohio california poppy guideZones 6–10Flat Rock's 6a is its exact cold limit.
garlic, photograph
Garlic in OhioZones 2–10Flat Rock's 6a — 4 zones of cold margin.
blackberry, photograph
Blackberry: Ohio growing notesZones 5–8Flat Rock's 6a — 1 zone of cold margin.
St. Johns wort, photograph
Growing st. johns wort in OhioZones 3–8Flat Rock's 6a — 3 zones of cold margin.
kale, photograph
Ohio kale guideZones 2–11Flat Rock's 6a — 4 zones of cold margin.
cranberry, photograph
Cranberry in OhioZones 2–7Flat Rock's 6a — 4 zones of cold margin.
Turkish rocket, photograph
Turkish rocket: Ohio growing notesFlat Rock's 203 days clear the ~90 it needs.
lentil, photograph
Growing lentil in OhioZones 2–11Flat Rock's 203 days clear the ~70 it needs.
okra, photograph
Ohio okra guideZones 2–12Flat Rock's 203 days clear the ~50 it needs.
potato, photograph
Potato in OhioZones 2–11Flat Rock's 6a — 4 zones of cold margin.
hosta, photograph
Hosta: Ohio growing notesZones 3–8Flat Rock's 6a — 3 zones of cold margin.
sunflower, photograph
Growing sunflower in OhioZones 2–11Flat Rock's 203 days clear the ~70 it needs.
azalea, photograph
Ohio azalea guideZones 4–8Flat Rock's 6a — 2 zones of cold margin.
hops, photograph
Hops in OhioZones 3–8Flat Rock's 6a — 3 zones of cold margin.
iris, photograph
Iris: Ohio growing notesZones 3–10Flat Rock's 6a — 3 zones of cold margin.
French marigold, photograph
Growing french marigold in OhioFlat Rock's 203 days clear the ~50 it needs.
lilac, photograph
Ohio lilac guideZones 4–10Flat Rock's 6a — 2 zones of cold margin.
American bittersweet, photograph
American bittersweet in OhioZones 3–8Flat Rock's 6a — 3 zones of cold margin.
tulip, photograph
Tulip: Ohio growing notesZones 6–8Flat Rock's 6a is its exact cold limit.
American elm, photograph
Growing american elm in OhioZones 3–9Flat Rock's 6a — 3 zones of cold margin.
Ethiopian mustard, photograph
Ohio ethiopian mustard guideZones 4–10Flat Rock's 6a — 2 zones of cold margin.
Kentucky bluegrass, botanical illustration
Kentucky bluegrass in OhioZones 2–7Flat Rock's 6a — 4 zones of cold margin.
Douglas fir, photograph
Douglas fir: Ohio growing notesZones 4–10Flat Rock's 6a — 2 zones of cold margin.
alfalfa, photograph
Growing alfalfa in OhioZones 2–10Flat Rock's 203 days clear the ~100 it needs.
Canada wild rye, photograph
Ohio canada wild rye guideZones 3–8Flat Rock's 6a — 3 zones of cold margin.

Is it too late to plant in Flat Rock?

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 18; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 15 (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 Flat Rock

Spotted lanternfly documented 16 miles from Flat Rock, first recorded 2023. What to watch for.

What's on the federal record near Flat Rock

Closest first, within ~10 miles of Flat Rock. Listing isn't leaking, and distance isn't exposure.

  1. THOMPSON TWP TRUSTEESUnderground Storage Tanks · 300 ft
  2. FRANKLIN D. HAMMONDUnderground Storage Tanks · 300 ft
  3. FLAT ROCK CHILDREN HOMEUnderground Storage Tanks · 300 ft
  4. BELLEVUE CITYPFAS · 1.0 mi
  5. OHIO TURNPIKE CASTALIA SECTIONBrownfields · 1.1 mi
  6. WILBERT PLASTIC SERVICESBrownfields · 1.9 mi
  7. TOWER AUTOMOTIVEBrownfields · 1.9 mi
  8. TOWER AUTOMOTIVEToxics Release Inventory · 1.9 mi
  9. HOGUE'S IGA SUPERMARKETUnderground Storage Tanks · 2.0 mi
  10. NORFOLK & SOUTHERN RAILWAY CO.Underground Storage Tanks · 2.1 mi
  11. DE'S L.P. GAS INC.Underground Storage Tanks · 2.1 mi
  12. BELLEVUE MICKEY MARTUnderground Storage Tanks · 2.1 mi

6 more sites are on the record inside the same radius. See them on the map

Measured from Flat Rock'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 Flat Rock.

Total Sites

176

within ~10 miles of Flat Rock

Risk Level

Elevated

Highest-severity

5 Superfund sites (none NPL-listed)

Severity Distribution

within ~10 miles of Flat Rock

High2Moderate55Low119

Highest-Severity Sites

Bellevue City
PFAS Sampling · PFAS Detected
Horn'S Crop Service Center INC
Toxics Release Inventory · 44811hrnsc15581
Marie a. Miller
Underground Storage Tanks · Open UST(S)
Vzb - Rblfoh
Underground Storage Tanks · Open UST(S)

A note from Gnorman

What an experienced grower watches for around here

In and around Flat Rock, two things run higher than the national average within ~10 miles of Flat Rock — Superfund (5 sites) and Toxics Release Inventory (13 sites). That's not a problem with your land — it's information about it.

Superfund: Superfund sites represent the most severe contamination in the federal system.

Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.

Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).

Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.

Free Report

Check your specific parcel in Flat Rock

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 Flat Rock average

Your land is one point inside Flat Rock

Everything above resolves to Flat Rock as a whole — one PHZM band and one 28°F frost record, read across 136 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 Flat Rock Average

Flat Rock Average

  • USDA Zones 6a, averaged across Flat Rock
  • One soil character for all of Flat Rock
  • Frost dates read at Flat Rock's scale: Apr 15 to Nov 4

YOUR Parcel

  • Your exact zone, not Flat Rock's 6a
  • Your SSURGO soil type & pH
  • Your sun exposure, cast in 3D

See MY Growing Report

Free Report

Read your specific parcel in Flat Rock

Pull a site-specific report for your exact address in Flat Rock, Ohio — soil, sun, drainage, frost risk, and scored plant recommendations.

Three things about your lot that Flat Rock averages can't show:

Your soil pHYour frost-free days — Flat Rock averages 203Your sun & shade

We read public map data around Flat Rock — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the Flat Rock average

How we know this about Flat Rock

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 Flat Rock’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 Flat Rock

When does frost risk typically end in Flat Rock?

The last hard freeze (28°F) in Flat Rock typically lands around Apr 15, 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 6.

When is the first frost in Flat Rock?

The first hard freeze (28°F) in Flat Rock 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 203 days after the spring freeze cleared.

How long is the growing season in Flat Rock?

Measured between 28°F hard freezes, Flat Rock sees about 203 frost-free days — roughly Apr 15 through Nov 4, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 6 to Oct 21, about 168 days.

Is the soil safe to grow vegetables in Flat Rock?

The federal record around Flat Rock is a meaningful one — 176 documented sites, mostly Underground Storage Tanks entries (83), 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 Flat Rock?

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 Flat Rock's scale — its 6a band and its 203-day season. Your yard writes its own version of Flat Rock'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 Flat Rock’s own scale

7 of the readings below were taken at Flat Rock's own scale — its own ~203-day season between 28°F freezes, the 136 acres it covers and 176 documented sites around it; 4 are borrowed from a wider read, named and linked below.

Measured here

  • Flat Rock's own USDA hardiness band, zones 6aUSDA PHZM 2023
  • Flat Rock's own 28°F hard-freeze dates, about Apr 15 and Nov 4 and the ~203-day span between themNOAA 1991–2020 Climate Normals
  • 176 documented contamination sites on the federal record near Flat Rock, the closest Underground Storage Tanks record under a tenth of a mile out from the town centreFederal environmental registers
  • Flat Rock's boundary and the 136 acres inside itUS Census TIGER/Line 2025
  • Which of 1,086 plants clear zones 6a and a ~203-day seasonGrowable Ground crop-matching engine
  • The ecoregion at Flat Rock's own centroid, the Huron/Erie Lake PlainsUS EPA Level III Ecoregions
  • A documented spotted-lanternfly record within reach of Flat Rocklydemapr (De Bona & Helmus), 10 km survey lattice

Inherited from a wider read

  • Soil character — no town-scale survey exists, so Flat Rock's 136 acres read through its county's SSURGO summaryfrom Seneca County
  • Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Seneca 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 Seneca County

What this page can’t tell you

  • The soil pH, drainage, sun hours, and frost pockets on any one lot among Flat Rock's 136 acreswhy one lot differs from the next
  • Which side of Flat Rock you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 136 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 Flat Rock-wide figureread your own land
The next step finer is your own address

More in Ohio

Wider growing context

What grows across Ohio

Flat Rock sits outside our named growing regions, so Ohio as a whole is its closest context here.