Smithtown, New York, sits in USDA hardiness zone 7b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
These conditions suit cabbage, prickly pear, california poppy, and collard greens — a starting list any specific site will trim or extend with its own soil, sun, and drainage.
Even in Smithtown, 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 Smithtown 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 Smithtown — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Smithtown — the short answer
Smithtown, New York: USDA zone 7b, about 238 days between hard freezes, across 8K acres of town.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 27
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 20
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~238
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 8K 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 7b is Smithtown's average, not your lot's — a low corner or a tree line moves it. Against Smithtown's 238-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Smithtown
Each reading below is measured for Smithtown itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSmithtown runs about 238 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
MeasuredSmithtown sits in USDA hardiness zone 7b.
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 Smithtown is in
Smithtown sits in the Northeastern Coastal Zone — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Smithtown's own centroid, and it is not what its county reads: Suffolk County is mostly Atlantic Coastal Pine Barrens. The wider page above you is answering a different question about different ground.
What Grows in Smithtown
Every plant below cleared Smithtown's own zone 7b and its 238-day season. Each card opens that plant's New York profile. How we score.
Is it too late to plant in Smithtown?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Feb 27; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 27 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 20 — 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 Smithtown
Spotted lanternfly documented 4 miles from Smithtown, first recorded 2023. What to watch for.
What's on the federal record near Smithtown
Closest first, within ~10 miles of Smithtown. Listing isn't leaking, and distance isn't exposure.
- S 42270. 1Nitrate · 2000 ft
- S 51265. 1Nitrate · 2100 ft
- S 42473. 1Nitrate · 2100 ft
- SMITHTOWN WATER DISTRICTPFAS · 2200 ft
- CALEB SMITH STATE PARKUnderground Storage Tanks · 0.6 mi
- SONGS DANDY CLEANERSBrownfields · 0.6 mi
- PIT STOPUnderground Storage Tanks · 0.6 mi
- SMITHTOWN NEWS INC THEBrownfields · 0.7 mi
- BP PRODUCTS NORTH AMERICA - BP 66384Brownfields · 0.7 mi
- ST CATHERINE OF SIENA MEDICAL CENTERBrownfields · 0.7 mi
- HI-TECH CLEANERSBrownfields · 0.8 mi
- SMITHTOWN VILLAGE ANIMAL HOSPITALBrownfields · 0.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Smithtown'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 Smithtown.
Sources Checked
within ~10 miles of Smithtown
Severity Distribution
within ~10 miles of Smithtown
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Smithtown, two things run higher than the national average within ~10 miles of Smithtown — Nitrate (1,046 sites) and Brownfields (1,260 sites). It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Nitrate: Nitrate contamination primarily comes from agricultural fertilizer runoff and failing septic systems.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Check your specific parcel in Smithtown
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 Smithtown average
Your land is one point inside Smithtown
Everything above resolves to Smithtown as a whole — one PHZM band and one 28°F frost record, read across 8K 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 Smithtown Average
Smithtown Average
- ●USDA Zones 7b, averaged across Smithtown
- ●One soil character for all of Smithtown
- ●Frost dates read at Smithtown's scale: Mar 27 to Nov 20
YOUR Parcel
- ✓Your exact zone, not Smithtown's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Smithtown
Pull a site-specific report for your exact address in Smithtown, New York — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Smithtown averages can't show:
We read public map data around Smithtown — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Smithtown average
How we know this about Smithtown
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 Smithtown’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 Smithtown
When does frost risk typically end in Smithtown?
The last hard freeze (28°F) in Smithtown typically lands around Mar 27, 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 17.
When is the first frost in Smithtown?
The first hard freeze (28°F) in Smithtown typically arrives around Nov 20, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 6, so the watching starts about Oct 21 — about 238 days after the spring freeze cleared.
How long is the growing season in Smithtown?
Measured between 28°F hard freezes, Smithtown sees about 238 frost-free days — roughly Mar 27 through Nov 20, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 17 to Nov 6, about 203 days.
Is the soil safe to grow vegetables in Smithtown?
The federal record around Smithtown runs heavier than most — 2,547 documented sites, mostly Brownfields entries (1,260), the nearest Nitrate record about 0.4 miles out — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
How do I protect my plants from frost in Smithtown?
From about Oct 21 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 20 (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 20. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Smithtown's scale — its 7b band and its 238-day season. Your yard writes its own version of Smithtown'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 Smithtown’s own scale
7 of the readings below were taken at Smithtown's own scale — its own ~238-day season between 28°F freezes, the 7,633 acres it covers and 2,547 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Smithtown's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Smithtown's own 28°F hard-freeze dates, about Mar 27 and Nov 20 and the ~238-day span between themNOAA 1991–2020 Climate Normals
- 2,547 documented contamination sites on the federal record near Smithtown, the closest Nitrate record about 0.4 miles out from the town centreFederal environmental registers
- Smithtown's boundary and the 7,633 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~238-day seasonGrowable Ground crop-matching engine
- Smithtown sits in the Northeastern Coastal Zone — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Smithtownlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Smithtown's 7,633 acres read through its county's SSURGO summaryfrom Suffolk County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Suffolk County
- The growing challenges every New York grower plans around — written at state scale, so they stay on the state guidefrom New York
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Suffolk County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Smithtown's 7,633 acreswhy one lot differs from the next →
- Which side of Smithtown you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 7,633 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.4 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 Smithtown-wide figureread your own land →