What Grows in Smithtown, New York

USDA Zones 6a-7b · 8K acres

Smithtown, New York, sits in USDA hardiness zones 6a-7b — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.

These conditions suit apple, grape, garlic, and kale — a starting list any specific site will trim or extend with its own soil, sun, and drainage.

Score your parcel · free

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 1,112 plants against your land's actual soil, sun, and frost.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

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Quick Facts

USDA Zones

6a-7b

Last Hard Freeze (28°F)

Mar 20

Town normal — light frosts run a few weeks later

First Hard Freeze (28°F)

Dec 6

Town normal — light frosts arrive a few weeks earlier

Town Area

8K acres

Hardiness Zone Range

6a
7b
3a (Cold)13b (Hot)

Zone maps are averages across Smithtown. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.

Soil varies lot by lot — soil types explained.

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 20; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 20 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 6 — long-season crops need about 90 days of runway, quick greens only 30. And with a calendar this mild, the honest answer is that planting barely stops — winter opens seasons colder regions never see.

Growing Challenges in New York

What an experienced grower plans around here — each one has a move.

Short upstate growing season (100-140 frost-free days in Adirondacks)

Fast varieties plus season extension: a low tunnel or cold frame reliably buys back the missing weeks.

Heavy clay soils in western NY require drainage improvement

A raised bed solves the drainage the first season; long-term, steady compost works that clay into excellent loam.

Late spring frosts through May in higher elevations

Plant to your elevation's real frost dates, not the valley's — two weeks of patience saves a full replanting.

Deer browse pressure is heavy in suburban and rural areas

Fencing is the control that works; behind it, aromatic herbs, ferns, and daffodils are the plants deer tend to pass by.

For cultivar selection, pest pressure, and planting-time guidance specific to New York, the Cornell Cooperative Extension is the authoritative local source.

Environmental Intelligence

Understanding what's nearby helps you make informed decisions about where and how to grow.

Total Sites

2,547

within ~10 miles of Smithtown

Risk Level

High

Highest-severity

21 Superfund sites

Severity Distribution

within ~10 miles of Smithtown

High23Moderate1,241Low1,283

Highest-Severity Sites

139 Burrs Lane, Dix Hills, Ny
Superfund · Superfund (Non-NPL)
277 Pine Acres Blvd
Superfund · Superfund (Non-NPL)
A & G Materials
Superfund · Superfund (Non-NPL)
Bioclinical Laboratories, INC.
Superfund · Superfund NPL
Commercial Envelope Mfg. CO., INC.
Superfund · Superfund (Non-NPL)

A note from Gnorman

What an experienced grower watches for around here

In and around Smithtown, two things run higher than the national average — 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.

Free Report

Check your specific parcel in Smithtown

Get exact proximity distances to contamination sources for your specific parcel — plus soil, sun, drainage, and 1,112 plant recommendations.

Three things about your exact spot that zone averages miss:

Your soil pHYour frost-free daysYour sun & shade

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources analyzed in seconds

Your Specific Parcel Matters

Smithtown Average

  • USDA Zones 6a-7b
  • Generic soil type for the area
  • State-average frost dates

YOUR Parcel

  • Your exact hardiness zone
  • Your SSURGO soil type & pH
  • Your sun exposure, cast in 3D

See MY Growing Report

Free 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 exact spot that zone averages miss:

Your soil pHYour frost-free daysYour sun & shade

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources analyzed in seconds

Key Growing Facts for Smithtown, New York

  • USDA Hardiness Zones: 6a-7b (USDA PHZM 2023)
  • Last Hard Freeze (28°F): Mar 20 (town normal, NOAA 1991–2020 Climate Normals — light frosts can follow for a few weeks)
  • First Hard Freeze (28°F): Dec 6 (town normal, NOAA 1991–2020 Climate Normals — light frosts can arrive a few weeks earlier)
  • Days Between Hard Freezes: ~261 (town normal, NOAA 1991–2020 Climate Normals)
  • Land Area: 8K acres (US Census TIGER 2025)

Zone data: USDA ARS Plant Hardiness Zone Map 2023. Climate data: NOAA NCEI. Boundaries: US Census TIGER/Line 2025.

Frequently Asked Questions

What hardiness zone is Smithtown, New York?

Smithtown sits in USDA hardiness zones 6a-7b, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.

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 20; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 20 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Dec 6 — long-season crops need about 90 days of runway, quick greens only 30. And with a calendar this mild, the honest answer is that planting barely stops — winter opens seasons colder regions never see.

When does frost risk typically end in Smithtown?

The last hard freeze (28°F) in Smithtown typically lands around Mar 20, per NOAA 1991–2020 climate normals — an earlier marker than the light-frost dates many planting charts quote. That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.

When is the first frost in Smithtown?

The first hard freeze (28°F) in Smithtown typically arrives around Dec 6, per NOAA 1991–2020 climate normals — the point most tender summer crops finish. Lighter frosts usually reach a couple of weeks earlier, so watch the forecast from late summer on and harvest or cover tender plants before the first cold night.

What vegetables grow in Smithtown?

Smithtown's zones 6a-7b support a wide range — strong performers include Apple, Grape, Garlic, Kale, and Sugar Maple. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.

Which hardiness zone is Smithtown, really?

Officially, Smithtown sits in USDA zones 6a-7b (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,112 plants against what's actually there.

Is the soil safe to grow vegetables in Smithtown?

The federal record around Smithtown runs heavier than most — 2,547 documented sites — 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?

As the season closes around the first 28°F hard freeze near Dec 6 (NOAA 1991–2020 climate normals), a few moves buy time: cover tender plants with floating row cover or an old sheet on still, clear nights, water the soil the afternoon before a freeze so it holds warmth overnight, and harvest frost-tender crops like tomatoes, peppers, and basil before the first hard night. Hardy greens and root crops shrug off light frost and often sweeten after it, so leave them in.

Everything on this page is a Smithtown average. Your yard writes its own version — we read soil, sun, drainage, and frost at your exact address. Try it for 14 days — no card required.