Sullivan County, in New York, sits in USDA hardiness zone 6a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
Reliable performers under these conditions include cabbage, blackberry, california poppy, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Sullivan County lies within the Catskills — a regional growing area with its own character.
Grounded in USDA PHZM 2023 · Growable Ground suitability scoring · NOAA 1991–2020 Climate Normals
Sullivan County holds more than one microclimate.
Soils and elevations shift across Sullivan 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 Sullivan County — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Sullivan County — the short answer
Sullivan County, New York: USDA zone 6a, about 179 days between hard freezes, across 620K acres.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 23
- NOAA 1991–2020 Climate Normals, 28°F
- First hard freeze (28°F)
- Oct 19
- NOAA 1991–2020 Climate Normals, 28°F
- Days between freezes
- ~179
- NOAA 1991–2020 Climate Normals, 28°F
- County area
- 620K 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 6a is Sullivan County's average, not your lot's — a low corner or a tree line moves it. Against Sullivan County's 179-day season, see what your own ground reads.
Heat in Sullivan County
Across a year, Sullivan County accumulates about 2,091 growing degree days above 50°F, about 145 fewer than the middle New York county — ahead of 23 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 Sullivan County
Across Sullivan County, the ground is predominantly Inceptisols, where Wellsboro, Wurtsboro, and Arnot are the most extensive named soil series. The soil is generally moderately well drained with a loam surface. Topsoil pH runs about 4.6–5.3, very strongly acidic. Rainfall drains through hydrologic group D soils.
Soil order
Inceptisols
Drainage
Moderately well drained
Prime farmland
5%
Hydric soils
6%
Soil still varies lot by lot — soil types explained.
How the ground varies across Sullivan County
The USDA soil survey maps 36% of Sullivan County as moderately well drained — but another 59% drains differently: 34% well drained, 13% somewhat excessively drained.
Wellsboro is the most extensive named soil at 18% of mapped acres, then Wurtsboro (11%) and Arnot (10%).
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 Sullivan County
Each reading below is measured for Sullivan 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 Sullivan County are moderately well drained, in hydrologic group D — roughly the middle of the drainage range.
This is close to the middle most vegetables prefer: it holds enough water to carry a crop between rains without staying waterlogged. The catch is that a wet spring or a low corner can still tip it soggy.
Plant on the site as-is for most crops, but keep the lowest, slowest-draining beds for moisture-tolerant plantings.
USDA NRCS SSURGO
Surface pH
MeasuredTopsoil across Sullivan County runs about pH 4.6–5.3, on the acidic side.
Blueberries, potatoes, and rhododendrons thrive in it, but most vegetables start locking out nutrients below about pH 6.0 and grow pale and stunted no matter how much you feed them.
A measured lime application raises pH for the crops that need it — but test first, because the right rate depends on your own soil, not the county average.
USDA NRCS SSURGO
Season length
MeasuredSullivan County runs about 179 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
MeasuredSullivan County 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 Sullivan County is in
Sullivan County spans 3 EPA Level III ecoregions — Northern Allegheny Plateau (50%), North Central Appalachians (38%) and Northeastern Highlands (8%). 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 Sullivan County
We scored all 1,086 plants against Sullivan County's own USDA zone 6a and its own 179-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 Sullivan County?
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 26; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 23 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 19 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
Documented around Sullivan County
Spotted lanternfly documented 8 miles from Sullivan County, first recorded 2022. What to watch for.
- Japanese beetle8 documented records
- monarch butterfly26 documented records
Sighting records, so they follow observers as much as insects.
What gets applied to farmland in Sullivan County
USGS estimates 686 lb of Glyphosate on Sullivan County farmland in 2019, its largest by weight, ahead of Metolachlor & Metolachlor-s (520 lb) and 2,4-d (334 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 Sullivan County — and how to grow with it.
We checked the federal record across Sullivan County — 642 documented sites across 8 of the 9 source types we track.
The most significant on record: 3 Superfund sites. 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 Sullivan 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 Sullivan County
Closest first, across Sullivan County. Listing isn't leaking, and distance isn't exposure.
- BELLA POULTRY INC.CAFO · 0.7 mi
- YGS TORAH CENTERUnderground Storage Tanks · 1.4 mi
- CAMP BNOS YAKOVUnderground Storage Tanks · 1.5 mi
- CATSKILL REGIONAL MEDICAL CENTERUnderground Storage Tanks · 1.9 mi
- GARNET HEALTH MEDICAL CENTER-CATSKILLSBrownfields · 2.0 mi
- HUDSON VALLEY FOIE GRAS, LLCUnderground Storage Tanks · 2.1 mi
- YANKEE HARAGEUnderground Storage Tanks · 2.1 mi
- NYSDOT REG 9 - CR 174 OVER RTE 17Brownfields · 2.2 mi
- MAMMA SAYS NY, LLCUnderground Storage Tanks · 2.2 mi
- LABELLE FARM, INCCAFO · 2.3 mi
- SWAN LAKE COUNTRY STOREUnderground Storage Tanks · 2.3 mi
- SWAN LAKE HOTELUnderground Storage Tanks · 2.4 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Sullivan 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 Sullivan County.
Severity Distribution
across Sullivan County
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Sullivan County, two things run higher than the national average across Sullivan County — CAFO (10 sites) and Underground Storage Tanks (433 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.
Underground Storage Tanks: Underground storage tanks are the single most common source of soil contamination near homes and gardens.
Wash all produce consumed raw thoroughly, especially leafy greens grown near CAFOs.
Use raised beds with imported soil — this eliminates the primary soil-contact pathway.
Check your specific parcel in Sullivan 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 Sullivan County average
Your land is one point inside Sullivan County
Everything above resolves to Sullivan County as a whole — one PHZM band and one county frost record, read across 620K 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 Sullivan County Average
Sullivan County Average
- ●USDA Zones 6a, averaged across Sullivan County
- ●One soil character for all of Sullivan County
- ●Frost dates read at Sullivan County's scale: Apr 23 to Oct 19
YOUR Parcel
- ✓Your exact zone, not Sullivan County's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your parcel in Sullivan County
Pull a site-specific report for your exact address in Sullivan County, New York — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Sullivan County averages can't show:
We read public map data around Sullivan County — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Sullivan County average
How we know this about Sullivan 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 Sullivan County carries no record of its own, the figure is inherited and labelled — the resolution ledger below names each.
Common questions about Sullivan County
When does frost risk typically end in Sullivan County?
The last hard freeze (28°F) in Sullivan County typically lands around Apr 23, 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 14.
How long is the growing season in Sullivan County?
Measured between 28°F hard freezes, Sullivan County sees about 179 frost-free days — roughly Apr 23 through Oct 19, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 14 to Oct 5, about 144 days.
Is the soil safe to grow vegetables in Sullivan County?
The federal record around Sullivan County is a meaningful one — 642 documented sites, mostly Underground Storage Tanks entries (433), the nearest CAFO record about 0.7 miles 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 Sullivan County's scale — its 6a band and its 179-day season. Your yard writes its own version of Sullivan 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 Sullivan County’s own scale
9 of the readings below were taken at Sullivan County's own scale — its own ~179-day span between 28°F freezes, the 3 most extensive soil series mapped here and 642 documented sites inside its boundary; one is borrowed from a wider read, named and linked below.
Measured here
- Sullivan County's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Sullivan County's own 28°F hard-freeze dates and its ~179-day span between themNOAA 1991–2020 Climate Normals
- The soil order, drainage, surface pH, and the 3 most extensive named soil series mapped in Sullivan CountyUSDA NRCS SSURGO
- 642 documented contamination sites inside the county boundary, distance-sorted from its center — the closest CAFO record about 0.7 miles outFederal environmental registers
- Sullivan County's boundary and the 619,612 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~179-day seasonGrowable Ground crop-matching engine
- The 3 ecoregions Sullivan County spans, Northern Allegheny Plateau the largestUS EPA Level III Ecoregions
- Open occurrence records documented in Sullivan County for 2 tracked speciesGBIF derived datasets (CC0 / CC BY 4.0)
- Which agricultural compounds go onto Sullivan 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 Sullivan County — the ~179 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 Sullivan County's 619,612 acreswhy one lot differs from the next →
- Which of those 642 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 Sullivan Countyread your own land →