Ontario County, in New York, sits in USDA hardiness zone 6b — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
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.
Ontario County lies within the Finger Lakes — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Ontario County holds more than one microclimate.
Soils and elevations shift across Ontario County, so your frost dates and drainage aren't the county average. 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 Ontario County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Ontario County — the short answer
Ontario County, New York: USDA zone 6b, about 201 days between hard freezes, across 412K acres.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 17
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Nov 4
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~201
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 412K acres
- US Census TIGER/Line 2025
Every figure names the dataset it came from. Hard-freeze dates are county 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 Ontario County's average, not your lot's — a low corner or a tree line moves it. Against Ontario County's 201-day season, see what your own ground reads.
Heat in Ontario County
Across a year, Ontario County accumulates about 2,412 growing degree days above 50°F, about 176 more than the middle New York county — ahead of 43 of New York’s 62 counties. Degree days are the heat a crop actually gets to work with — more of them is more room to ripen a long-season crop before the freeze closes the window.
Grounded in PRISM Climate Group, Oregon State University — 1991–2020 monthly normals
Soil in Ontario County
Across Ontario County, the ground is predominantly Alfisols, where Lima, Honeoye, and Schoharie are the most extensive named soil series. The soil is generally well drained with a loam surface. Topsoil pH runs about 5.8–7.0, slightly acidic. Rainfall drains through hydrologic group B soils.
Soil order
Alfisols
Drainage
Well drained
Prime farmland
39%
Hydric soils
9%
Soil still varies lot by lot — soil types explained.
How the ground varies across Ontario County
The USDA soil survey maps 39% of Ontario County as well drained — but another 56% drains differently: 30% moderately well drained, 17% somewhat poorly drained.
Lima is the most extensive named soil at 10% of mapped acres, then Honeoye (8%) and Schoharie (7%).
Which of them your own lot sits on is a parcel question, not a county one. Check your address for the survey at your boundary.
What this means for growing in Ontario County
Each reading below is measured for Ontario County itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Drainage
MeasuredThe dominant soils across Ontario County are well drained, in hydrologic group B — ground that drains quickly.
The upside is soil you can work early in spring and roots that never drown; the cost is that fast-draining ground dries out fast and leaches nutrients away before plants can use them.
Work in compost and mulch to hold moisture and feed, and water more often in short doses than deep and rarely.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Ontario County runs about pH 5.8–7.0, close to neutral.
This is the range most vegetables prefer — one correction you probably do not have to make, which is genuinely good news for a new bed.
Keep it there with compost rather than lime or sulfur, and only amend if your own soil test says otherwise.
USDA NRCS SSURGO
Season length
MeasuredOntario County runs about 201 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
MeasuredOntario County 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 Ontario County is in
Ontario County spans 2 EPA Level III ecoregions — Eastern Great Lakes Lowlands (67%) and Northern Allegheny Plateau (33%). Which one your land falls in changes what grows wild there and how the ground behaves, and a county-wide answer cannot tell you which.
What Grows in Ontario County
We scored all 1,086 plants against Ontario County's own USDA zone 6b and its own 201-day season between hard freezes, using the same matching engine that runs a full parcel report. These cleared both. Sun, soil pH and drainage vary lot by lot — those are the parcel questions below. Each card opens that plant's New York profile.
Is it too late to plant in Ontario County?
Almost never — the real question is what to plant next. 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 Nov 4 — long-season crops need about 90 days of runway, quick greens only 30. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
Documented around Ontario County
Spotted lanternfly documented 19 miles from Ontario County, first recorded 2022. What to watch for.
- Japanese beetle8 documented records
- monarch butterfly13 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Ontario County
USGS estimates 72,552 lb of Glyphosate on Ontario County farmland in 2019, its largest by weight, ahead of Atrazine (45,161 lb) and Metolachlor & Metolachlor-s (26,687 lb).
Farmland across the whole county, not any one lot. Check your address for the site-by-site record.
Safe to Grow Here?
What the federal record shows across Ontario County — and how to grow with it.
We checked the federal record across Ontario County — 766 documented sites across 7 of the 9 source types we track.
The most significant on record: 8 Superfund sites (none NPL-listed). Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
There's a meaningful federal record across Ontario County — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What's on the federal record near Ontario County
Closest first, across Ontario County. Listing isn't leaking, and distance isn't exposure.
- BRISTOL WD #1PFAS · 25 ft
- BRISTOL HARBOUR WATER CORPPFAS · 25 ft
- CANANDAIGUA CITYPFAS · 25 ft
- CANANDAIGUA TOWN CONS. WDPFAS · 25 ft
- C & D DAIRY FARMCAFO · 1.1 mi
- CITY OF CANANDAIGUAUnderground Storage Tanks · 1.4 mi
- CANANDAIGUA CITY OF WATER TREATMENT FACILITYBrownfields · 1.4 mi
- THOMPSON HEALTHUnderground Storage Tanks · 1.5 mi
- PLEASURE ACRESCAFO · 1.5 mi
- THOMPSON NURSING HOMEUnderground Storage Tanks · 1.6 mi
- CHARLES MILLERCAFO · 1.6 mi
- MONROE TRACTOR & IMPLEMENTBrownfields · 1.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Ontario County'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 Ontario County.
Total Sites
766
across Ontario County
Risk Level
Elevated
Highest-severity
8 Superfund sites (none NPL-listed)
Sources Checked
across Ontario County
Severity Distribution
across Ontario County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Ontario County, two things run higher than the national average across Ontario County — CAFO (45 sites) and PFAS (11 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
CAFO: CAFOs pose a different contamination profile than chemical sources.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Ontario County
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 Ontario County average
Your land is one point inside Ontario County
Everything above resolves to Ontario County as a whole — one PHZM band and one county frost record, read across 412K 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 county 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 county average.
Your Lot vs the Ontario County Average
Ontario County Average
- ●USDA Zones 6b, averaged across Ontario County
- ●One soil character for all of Ontario County
- ●Frost dates read at Ontario County's scale: Apr 17 to Nov 4
YOUR Parcel
- ✓Your exact zone, not Ontario County's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Ontario County
Pull a site-specific report for your exact address in Ontario County, New York — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Ontario County averages can't show:
We read public map data around Ontario County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Ontario County average
How we know this about Ontario County
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at county grain; hard-freeze dates from NOAA 1991–2020 28°F normals at this county’s own record where one resolves, and the labelled statewide window where none does; soils from the USDA NRCS SSURGO survey, area-weighted across the county’s own map units; boundaries and acreage from US Census TIGER/Line 2025; the contamination and pesticide records from the federal sources named in their beats above. Where Ontario County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Ontario County
When does frost risk typically end in Ontario County?
The last hard freeze (28°F) in Ontario County 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.
How long is the growing season in Ontario County?
Measured between 28°F hard freezes, Ontario County sees about 201 frost-free days — roughly Apr 17 through Nov 4, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 8 to Oct 21, about 166 days.
Is the soil safe to grow vegetables in Ontario County?
The federal record around Ontario County is a meaningful one — 766 documented sites, mostly Underground Storage Tanks entries (384), the nearest PFAS 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.
Everything above is measured at Ontario County's scale — its 6b band and its 201-day season. Your yard writes its own version of Ontario County's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
Will It Grow Here?
Zone fit is the first question — each answer below reads New York's frost window, season length, and soil profile against the plant's real requirements.
What this page reads at Ontario County’s own scale
9 of the readings below were taken at Ontario County's own scale — its own ~201-day span between 28°F freezes, the 3 most extensive soil series mapped here and 766 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Ontario County's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Ontario County's own 28°F hard-freeze dates and its ~201-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Ontario CountyUSDA NRCS SSURGO
- 766 documented contamination sites inside the county boundary, distance-sorted from its center — the closest PFAS record under a tenth of a mile outFederal environmental registers
- Ontario County's boundary and the 412,176 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~201-day seasonGrowable Ground crop-matching engine
- The 2 ecoregions Ontario County spans, Eastern Great Lakes Lowlands the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Ontario County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Ontario County farmland, and roughly how muchUSGS NAWQA EPest county estimates
Inherited from a wider read
- The growing challenges every New York grower plans around — written at state scale, so they stay on the state guidefrom New York
What this page can’t tell you
- How the season shifts across Ontario County — the ~201 days above is one reading at its centre; the 12 towns below each carry their owntowns in this county →
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Ontario County's 412,176 acreswhy one lot differs from the next →
- Which of those 766 documented sites actually reaches your soil — that needs your address, the wind, and the groundwater directionhow we read the record →
- Where cold air settles, which slopes face the sun, and which way the wind runs on your own ground — none of it survives being averaged over Ontario Countyread your own land →