Holtsville, New York, sits in USDA hardiness zone 7b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Reliable performers under these conditions include cabbage, prickly pear, california poppy, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in Holtsville, 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 Holtsville 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 Holtsville — soil, climate, flood, and parcel records. How we handle your address.
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Holtsville — the short answer
Holtsville, New York: USDA zone 7b, about 228 days between hard freezes, across 5K acres of town.
- USDA zone
- 7b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 30
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 13
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~228
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 5K 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 Holtsville's average, not your lot's — a low corner or a tree line moves it. Against Holtsville's 228-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Holtsville
Each reading below is measured for Holtsville itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredHoltsville runs about 228 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
MeasuredHoltsville 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 Holtsville is in
Holtsville sits in the Atlantic Coastal Pine Barrens — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Holtsville's own centroid rather than borrowed from Suffolk County.
What Grows in Holtsville
Every plant below cleared Holtsville's own zone 7b and its 228-day season. Each card opens that plant's New York profile. How we score.
Is it too late to plant in Holtsville?
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 2; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 30 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 13 — long-season crops need about 90 days of runway, quick greens only 30. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.
Documented around Holtsville
Spotted lanternfly documented 1 miles from Holtsville, first recorded 2020. What to watch for.
What's on the federal record near Holtsville
Closest first, within ~10 miles of Holtsville. Listing isn't leaking, and distance isn't exposure.
- TOPAZ LIGHTING CORPBrownfields · 1000 ft
- KEYSPAN ENERGY HOLTSVILLE LNG FACILITYToxics Release Inventory · 1100 ft
- S 47102. 1Nitrate · 1600 ft
- IRS BROOKHAVEN SERVICE CENTERBrownfields · 1600 ft
- J KINGS FOOD SERVICE PROFESSIONALS GENBrownfields · 1700 ft
- TRIPLE T MFG LTDBrownfields · 2000 ft
- BONDED BRAKESBrownfields · 2100 ft
- RITE AID #10659Brownfields · 2200 ft
- TANGRAM COMPANYBrownfields · 2300 ft
- TRADE-WINDS ENVIRONMENTAL RESTORATIONBrownfields · 2400 ft
- 895 WAVERLY ASSOCIATESBrownfields · 2400 ft
- SUFFOLK COUNTY DPW BIN 3364441 & 42 CR 97 NICOLLS RD OVER LIRR BRIDGEBrownfields · 2400 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Holtsville'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 Holtsville.
Sources Checked
within ~10 miles of Holtsville
Severity Distribution
within ~10 miles of Holtsville
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Holtsville, Nitrate runs higher than the national average — 1,314 sites within ~10 miles of Holtsville. That's not a problem with your land — it's information about 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 Holtsville
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 Holtsville average
Your land is one point inside Holtsville
Everything above resolves to Holtsville as a whole — one PHZM band and one 28°F frost record, read across 5K 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 Holtsville Average
Holtsville Average
- ●USDA Zones 7b, averaged across Holtsville
- ●One soil character for all of Holtsville
- ●Frost dates read at Holtsville's scale: Mar 30 to Nov 13
YOUR Parcel
- ✓Your exact zone, not Holtsville's 7b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Holtsville
Pull a site-specific report for your exact address in Holtsville, New York — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Holtsville averages can't show:
We read public map data around Holtsville — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Holtsville average
How we know this about Holtsville
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 Holtsville’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 Holtsville
When does frost risk typically end in Holtsville?
The last hard freeze (28°F) in Holtsville typically lands around Mar 30, 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 20.
When is the first frost in Holtsville?
The first hard freeze (28°F) in Holtsville typically arrives around Nov 13, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 30, so the watching starts about Oct 14 — about 228 days after the spring freeze cleared.
How long is the growing season in Holtsville?
Measured between 28°F hard freezes, Holtsville sees about 228 frost-free days — roughly Mar 30 through Nov 13, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 20 to Oct 30, about 193 days.
Is the soil safe to grow vegetables in Holtsville?
The federal record around Holtsville runs heavier than most — 2,497 documented sites, mostly Nitrate entries (1,314), the nearest Brownfields 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 Holtsville?
From about Oct 14 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 13 (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 13. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Holtsville's scale — its 7b band and its 228-day season. Your yard writes its own version of Holtsville'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 Holtsville’s own scale
7 of the readings below were taken at Holtsville's own scale — its own ~228-day season between 28°F freezes, the 4,550 acres it covers and 2,497 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Holtsville's own USDA hardiness band, zones 7bUSDA PHZM 2023
- Holtsville's own 28°F hard-freeze dates, about Mar 30 and Nov 13 and the ~228-day span between themNOAA 1991–2020 Climate Normals
- 2,497 documented contamination sites on the federal record near Holtsville, the closest Brownfields record about 0.2 miles out from the town centreFederal environmental registers
- Holtsville's boundary and the 4,550 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7b and a ~228-day seasonGrowable Ground crop-matching engine
- The ecoregion at Holtsville's own centroid, the Atlantic Coastal Pine BarrensUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Holtsvillelydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Holtsville's 4,550 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 Holtsville's 4,550 acreswhy one lot differs from the next →
- Which side of Holtsville you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 4,550 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields 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 Holtsville-wide figureread your own land →
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