Port Jefferson, Ohio, sits in USDA hardiness zone 6a — a range where zone-matched perennials and frost-aware annual timing set what succeeds.
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 Port Jefferson, 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 Port Jefferson 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 Port Jefferson — soil, climate, flood, and parcel records. How we handle your address.
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Port Jefferson — the short answer
Port Jefferson, Ohio: USDA zone 6a, about 200 days between hard freezes, across 97 acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 13
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 30
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~200
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 97 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 Port Jefferson's average, not your lot's — a low corner or a tree line moves it. Against Port Jefferson's 200-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Port Jefferson
Each reading below is measured for Port Jefferson itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredPort Jefferson runs about 200 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
MeasuredPort Jefferson 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 Port Jefferson is in
Port Jefferson sits in the Eastern Corn Belt Plains — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Port Jefferson's own centroid rather than borrowed from Shelby County.
What Grows in Port Jefferson
Every plant below cleared Port Jefferson's own zone 6a and its 200-day season. Each card opens that plant's Ohio profile. How we score.
Is it too late to plant in Port Jefferson?
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 16; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 13 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 30 — long-season crops need about 90 days of runway, quick greens only 30. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
Documented around Port Jefferson
Survey cells within 31 miles of Port Jefferson checked for spotted lanternfly, none carrying a detection — a surveyed negative, not an absence of looking. Nearest documented record 31 miles off. What to watch for.
What's on the federal record near Port Jefferson
Closest first, within ~10 miles of Port Jefferson. Listing isn't leaking, and distance isn't exposure.
- SHERWIN-WILLIAMS CO THEBrownfields · 450 ft
- DUNSON ENGINE REBUILDERSBrownfields · 750 ft
- NICHOLS GARAGEUnderground Storage Tanks · 900 ft
- VACANT BUILDINGUnderground Storage Tanks · 900 ft
- SIDNEY MANUFACTURINGBrownfields · 1200 ft
- SH-114Nitrate · 1.3 mi
- FABRICATION UNLIMITEDBrownfields · 1.6 mi
- MAPLEWOOD IMPLEMENT SALESBrownfields · 2.0 mi
- DELL DELIGHT FARMSUnderground Storage Tanks · 2.1 mi
- SHELBY COUNTY DRUM SITESuperfund · 3.1 mi
- M & W DEVELOPMENTUnderground Storage Tanks · 3.1 mi
- MILLIGAN CONSTRUCTION, INC.Underground Storage Tanks · 3.1 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Port Jefferson'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 Port Jefferson.
Total Sites
245
within ~10 miles of Port Jefferson
Risk Level
Elevated
Highest-severity
4 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Port Jefferson
Severity Distribution
within ~10 miles of Port Jefferson
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Port Jefferson, two things run higher than the national average within ~10 miles of Port Jefferson — Toxics Release Inventory (44 sites) and Superfund (4 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Toxics Release Inventory: TRI facilities report annual chemical releases to air, water, and land.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Check prevailing wind direction — downwind parcels face higher exposure than upwind or crosswind locations.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Port Jefferson
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 Port Jefferson average
Your land is one point inside Port Jefferson
Everything above resolves to Port Jefferson as a whole — one PHZM band and one 28°F frost record, read across 97 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 Port Jefferson Average
Port Jefferson Average
- ●USDA Zones 6a, averaged across Port Jefferson
- ●One soil character for all of Port Jefferson
- ●Frost dates read at Port Jefferson's scale: Apr 13 to Oct 30
YOUR Parcel
- ✓Your exact zone, not Port Jefferson's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Port Jefferson
Pull a site-specific report for your exact address in Port Jefferson, Ohio — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Port Jefferson averages can't show:
We read public map data around Port Jefferson — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Port Jefferson average
How we know this about Port Jefferson
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 Port Jefferson’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 Port Jefferson
When does frost risk typically end in Port Jefferson?
The last hard freeze (28°F) in Port Jefferson typically lands around Apr 13, 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 4.
When is the first frost in Port Jefferson?
The first hard freeze (28°F) in Port Jefferson typically arrives around Oct 30, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 16, so the watching starts about Sep 30 — about 200 days after the spring freeze cleared.
How long is the growing season in Port Jefferson?
Measured between 28°F hard freezes, Port Jefferson sees about 200 frost-free days — roughly Apr 13 through Oct 30, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 4 to Oct 16, about 165 days.
Is the soil safe to grow vegetables in Port Jefferson?
The federal record around Port Jefferson is a meaningful one — 245 documented sites, mostly Underground Storage Tanks entries (98), the nearest Brownfields 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 Port Jefferson?
From about Sep 30 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 30 (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 30. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Port Jefferson's scale — its 6a band and its 200-day season. Your yard writes its own version of Port Jefferson'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 Port Jefferson’s own scale
7 of the readings below were taken at Port Jefferson's own scale — its own ~200-day season between 28°F freezes, the 97 acres it covers and 245 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Port Jefferson's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Port Jefferson's own 28°F hard-freeze dates, about Apr 13 and Oct 30 and the ~200-day span between themNOAA 1991–2020 Climate Normals
- 245 documented contamination sites on the federal record near Port Jefferson, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- Port Jefferson's boundary and the 97 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~200-day seasonGrowable Ground crop-matching engine
- The ecoregion at Port Jefferson's own centroid, the Eastern Corn Belt PlainsUS EPA Level III Ecoregions
- Lanternfly survey cells around Port Jefferson 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 Port Jefferson's 97 acres read through its county's SSURGO summaryfrom Shelby County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Shelby 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 Shelby County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Port Jefferson's 97 acreswhy one lot differs from the next →
- Which side of Port Jefferson you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 97 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields 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 Port Jefferson-wide figureread your own land →
More in Ohio
Wider growing context
What grows across OhioPort Jefferson sits outside our named growing regions, so Ohio as a whole is its closest context here.
Nearby growing guides