Hewlett Harbor, New York, sits in USDA hardiness zone 7b — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
On paper, cabbage, prickly pear, california poppy, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Hewlett Harbor, 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 Hewlett Harbor 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 Hewlett Harbor — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Hewlett Harbor — the short answer
Hewlett Harbor, New York: USDA zone 7b, about 253 days between hard freezes, across 464 acres of town.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 20
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 28
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~253
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 464 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 Hewlett Harbor's average, not your lot's — a low corner or a tree line moves it. Against Hewlett Harbor's 253-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Hewlett Harbor
Each reading below is measured for Hewlett Harbor itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHewlett Harbor runs about 253 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
MeasuredHewlett Harbor 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 Hewlett Harbor is in
Hewlett Harbor sits in the Atlantic Coastal Pine Barrens — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Hewlett Harbor's own centroid, and it is not what its county reads: Nassau County is mostly Northeastern Coastal Zone. The wider page above you is answering a different question about different ground.
What Grows in Hewlett Harbor
Every plant below cleared Hewlett Harbor's own zone 7b and its 253-day season. Each card opens that plant's New York profile. How we score.
Is it too late to plant in Hewlett Harbor?
Rarely: the season closes in stages, not all at once, and each stage has its crops. 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 Nov 28 — long-season crops need about 90 days of runway, quick greens only 30. A long window like this one runs successions deep into fall — and even its last weeks take quick greens and garlic.
Documented around Hewlett Harbor
Spotted lanternfly documented 2 miles from Hewlett Harbor, first recorded 2021. What to watch for.
What's on the federal record near Hewlett Harbor
Closest first, within ~10 miles of Hewlett Harbor. Listing isn't leaking, and distance isn't exposure.
- N 7133. 1Nitrate · 1100 ft
- N 8655. 1Nitrate · 1800 ft
- N 8747. 1Nitrate · 1800 ft
- N 6965. 1Nitrate · 2500 ft
- N 3866. 1Nitrate · 0.5 mi
- N 3866. 2Nitrate · 0.5 mi
- N 4310. 1Nitrate · 0.6 mi
- PENINSULA BOULEVARD GROUNDWATER PLUMESuperfund · 0.7 mi
- PENINSULA BOULEVARD GROUNDWATER PLUMEBrownfields · 0.7 mi
- N 5589. 1Nitrate · 0.7 mi
- N 7235. 2Nitrate · 0.7 mi
- LYNBROOK SOUTH MIDDLE SCHOOLBrownfields · 0.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Hewlett Harbor'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 Hewlett Harbor.
Sources Checked
within ~10 miles of Hewlett Harbor
Severity Distribution
within ~10 miles of Hewlett Harbor
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Hewlett Harbor, Nitrate runs higher than the national average — 1,888 sites within ~10 miles of Hewlett Harbor. 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.
Test well water for nitrate if you rely on a private well for irrigation (EPA standard: 10 mg/L).
Check your specific parcel in Hewlett Harbor
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 Hewlett Harbor average
Your land is one point inside Hewlett Harbor
Everything above resolves to Hewlett Harbor as a whole — one PHZM band and one 28°F frost record, read across 464 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 Hewlett Harbor Average
Hewlett Harbor Average
- ●USDA Zones 7b, averaged across Hewlett Harbor
- ●One soil character for all of Hewlett Harbor
- ●Frost dates read at Hewlett Harbor's scale: Mar 20 to Nov 28
YOUR Parcel
- ✓Your exact zone, not Hewlett Harbor's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Hewlett Harbor
Pull a site-specific report for your exact address in Hewlett Harbor, New York — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Hewlett Harbor averages can't show:
We read public map data around Hewlett Harbor — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Hewlett Harbor average
How we know this about Hewlett Harbor
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 Hewlett Harbor’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 Hewlett Harbor
When does frost risk typically end in Hewlett Harbor?
The last hard freeze (28°F) in Hewlett Harbor typically lands around Mar 20, 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 10.
When is the first frost in Hewlett Harbor?
The first hard freeze (28°F) in Hewlett Harbor typically arrives around Nov 28, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 14, so the watching starts about Oct 29 — about 253 days after the spring freeze cleared.
How long is the growing season in Hewlett Harbor?
Measured between 28°F hard freezes, Hewlett Harbor sees about 253 frost-free days — roughly Mar 20 through Nov 28, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 10 to Nov 14, about 218 days.
Is the soil safe to grow vegetables in Hewlett Harbor?
The federal record around Hewlett Harbor runs heavier than most — 5,419 documented sites, mostly Nitrate entries (1,888), the nearest Nitrate record about 0.2 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 Hewlett Harbor?
From about Oct 29 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 28 (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 28. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Hewlett Harbor's scale — its 7b band and its 253-day season. Your yard writes its own version of Hewlett Harbor'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 Hewlett Harbor’s own scale
7 of the readings below were taken at Hewlett Harbor's own scale — its own ~253-day season between 28°F freezes, the 464 acres it covers and 5,419 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Hewlett Harbor's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Hewlett Harbor's own 28°F hard-freeze dates, about Mar 20 and Nov 28 and the ~253-day span between themNOAA 1991–2020 Climate Normals
- 5,419 documented contamination sites on the federal record near Hewlett Harbor, the closest Nitrate record about 0.2 miles out from the town centreFederal environmental registers
- Hewlett Harbor's boundary and the 464 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~253-day seasonGrowable Ground crop-matching engine
- Hewlett Harbor sits in the Atlantic Coastal Pine Barrens — not the ecoregion its county mostly readsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Hewlett Harborlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Hewlett Harbor's 464 acres read through its county's SSURGO summaryfrom Nassau County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Nassau 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 Nassau County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Hewlett Harbor's 464 acreswhy one lot differs from the next →
- Which side of Hewlett Harbor you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 464 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate record about 0.2 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 Hewlett Harbor-wide figureread your own land →