St. Henry, Ohio, sits in USDA hardiness zone 6a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Growers here do well with cabbage, hazelnut, lavender, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in St. Henry, 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 St. Henry 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 St. Henry — soil, climate, flood, and parcel records. How we handle your address.
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St. Henry — the short answer
St. Henry, Ohio: USDA zone 6a, about 208 days between hard freezes, across 1K acres of town.
- USDA zone
- 6a
- 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 2
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~208
- 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 6a is St. Henry's average, not your lot's — a low corner or a tree line moves it. Against St. Henry's 208-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in St. Henry
Each reading below is measured for St. Henry itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSt. Henry runs about 208 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
MeasuredSt. Henry 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 St. Henry is in
St. Henry sits in the Eastern Corn Belt Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at St. Henry's own centroid rather than borrowed from Mercer County.
What Grows in St. Henry
Every plant below cleared St. Henry's own zone 6a and its 208-day season. Each card opens that plant's Ohio profile. How we score.
Is it too late to plant in St. Henry?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. 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 2 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
Documented around St. Henry
Survey cells within 31 miles of St. Henry checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 53 miles off. What to watch for.
What's on the federal record near St. Henry
Closest first, within ~10 miles of St. Henry. Listing isn't leaking, and distance isn't exposure.
- OSTERHOLT SALES AND SERVICE INCBrownfields · 1100 ft
- A.K. CORNER STATIONUnderground Storage Tanks · 1100 ft
- CARRIAGE WERKES INCBrownfields · 1300 ft
- MERCER BEVERAGE CO.Underground Storage Tanks · 1500 ft
- SAINT HENRY FOOD MARTUnderground Storage Tanks · 1500 ft
- ST HENRY CONSOLIDATED SCHOOLSUnderground Storage Tanks · 1600 ft
- JACOBS & SONS LOGGING LTDUnderground Storage Tanks · 2600 ft
- HEMMELGARN MARATHONUnderground Storage Tanks · 2600 ft
- GELS ST HENRY IGAUnderground Storage Tanks · 0.5 mi
- TRU-EDGE GRINDING INCBrownfields · 0.5 mi
- NIEKAMP MARATHONUnderground Storage Tanks · 0.5 mi
- VILLAGE OF ST HENRYUnderground Storage Tanks · 0.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from St. Henry'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 St. Henry.
Total Sites
154
within ~10 miles of St. Henry
Risk Level
Moderate
Highest-severity
11 Toxics Release Inventory facilities
Sources Checked
within ~10 miles of St. Henry
Severity Distribution
within ~10 miles of St. Henry
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around St. Henry, Toxics Release Inventory runs higher than the national average — 11 sites within ~10 miles of St. Henry. 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 St. Henry
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 St. Henry average
Your land is one point inside St. Henry
Everything above resolves to St. Henry 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 St. Henry Average
St. Henry Average
- ●USDA Zones 6a, averaged across St. Henry
- ●One soil character for all of St. Henry
- ●Frost dates read at St. Henry's scale: Apr 8 to Nov 2
YOUR Parcel
- ✓Your exact zone, not St. Henry's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in St. Henry
Pull a site-specific report for your exact address in St. Henry, Ohio — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that St. Henry averages can't show:
We read public map data around St. Henry — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the St. Henry average
How we know this about St. Henry
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 St. Henry’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 St. Henry
When does frost risk typically end in St. Henry?
The last hard freeze (28°F) in St. Henry 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 St. Henry?
The first hard freeze (28°F) in St. Henry typically arrives around Nov 2, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 19, so the watching starts about Oct 3 — about 208 days after the spring freeze cleared.
How long is the growing season in St. Henry?
Measured between 28°F hard freezes, St. Henry sees about 208 frost-free days — roughly Apr 8 through Nov 2, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 29 to Oct 19, about 173 days.
Is the soil safe to grow vegetables in St. Henry?
The federal record around St. Henry shows 154 documented sites, mostly Underground Storage Tanks entries (80), the nearest Brownfields record about 0.2 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 St. Henry?
From about Oct 3 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 2 (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 2. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at St. Henry's scale — its 6a band and its 208-day season. Your yard writes its own version of St. Henry'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 St. Henry’s own scale
7 of the readings below were taken at St. Henry's own scale — its own ~208-day season between 28°F freezes, the 1,104 acres it covers and 154 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- St. Henry's own USDA hardiness band, zones 6aUSDA PHZM 2023
- St. Henry's own 28°F hard-freeze dates, about Apr 8 and Nov 2 and the ~208-day span between themNOAA 1991–2020 Climate Normals
- 154 documented contamination sites on the federal record near St. Henry, the closest Brownfields record about 0.2 miles out from the town centreFederal environmental registers
- St. Henry's boundary and the 1,104 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~208-day seasonGrowable Ground crop-matching engine
- The ecoregion at St. Henry's own centroid, the Eastern Corn Belt PlainsUS EPA Level III Ecoregions
- Lanternfly survey cells around St. Henry 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 St. Henry's 1,104 acres read through its county's SSURGO summaryfrom Mercer County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Mercer 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 Mercer County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among St. Henry's 1,104 acreswhy one lot differs from the next →
- Which side of St. Henry you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,104 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.2 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 St. Henry-wide figureread your own land →
More in Ohio
Wider growing context
What grows across OhioSt. Henry sits outside our named growing regions, so Ohio as a whole is its closest context here.
Nearby growing guides