Long Hill, Connecticut, sits in USDA hardiness zone 7a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Growers here do well with cabbage, hazelnut, california poppy, and collard greens — with the usual caveat that any single yard's soil, sun, and drainage cast the deciding vote.
Even in Long Hill, 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 Long Hill 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 Long Hill — soil, climate, flood, and parcel records. How we handle your address.
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Long Hill — the short answer
Long Hill, Connecticut: USDA zone 7a, about 233 days between hard freezes, across 984 acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 29
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 17
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~233
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 984 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 7a is Long Hill's average, not your lot's — a low corner or a tree line moves it. Against Long Hill's 233-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Long Hill
Each reading below is measured for Long Hill itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredLong Hill runs about 233 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
MeasuredLong Hill sits in USDA hardiness zone 7a.
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 Long Hill is in
Long Hill sits in the Northeastern Coastal Zone — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Long Hill's own centroid rather than borrowed from Southeastern Connecticut Planning Region.
What Grows in Long Hill
Every plant below cleared Long Hill's own zone 7a and its 233-day season. Each card opens that plant's Connecticut profile. How we score.
Is it too late to plant in Long Hill?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Cool-season crops can go in from around Mar 1; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 29 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 17 — 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 Long Hill
Spotted lanternfly documented 13 miles from Long Hill, first recorded 2022. What to watch for.
What's on the federal record near Long Hill
Closest first, within ~10 miles of Long Hill. Listing isn't leaking, and distance isn't exposure.
- SHERWIN WILLIAMS CO THE # 5433Brownfields · 1000 ft
- CVS PHARMACY 377Brownfields · 1100 ft
- LONG HILL SUNOCOUnderground Storage Tanks · 1200 ft
- DONCASTERS INC PRECISION CASTINGS NEW ENGLANDToxics Release Inventory · 1700 ft
- DONCASTERS INC PRECISION CASTINGS NEW ENGLANDBrownfields · 1700 ft
- GROTON AUTO BODYBrownfields · 1800 ft
- WYMAN-GORDON INVESTMENT CASTINGS, INCORPORATEDToxics Release Inventory · 1800 ft
- WYMAN-GORDON INVESTMENT CASTINGS, INCORPORATEDBrownfields · 1800 ft
- GROTON DENTAL GROUPBrownfields · 2000 ft
- GOODYEAR ASCUnderground Storage Tanks · 2100 ft
- GROTON REGENCYUnderground Storage Tanks · 2400 ft
- S&S TRANSMISSIONSUnderground Storage Tanks · 2600 ft
6 more sites are on the record inside the same radius. See them on the map
Measured from Long Hill'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 Long Hill.
Sources Checked
within ~10 miles of Long Hill
Severity Distribution
within ~10 miles of Long Hill
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Long Hill, two things run higher than the national average within ~10 miles of Long Hill — Superfund (17 sites) and PFAS (7 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Superfund: Superfund sites represent the most severe contamination in the federal system.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Long Hill
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 Long Hill average
Your land is one point inside Long Hill
Everything above resolves to Long Hill as a whole — one PHZM band and one 28°F frost record, read across 984 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 Long Hill Average
Long Hill Average
- ●USDA Zones 7a, averaged across Long Hill
- ●One soil character for all of Long Hill
- ●Frost dates read at Long Hill's scale: Mar 29 to Nov 17
YOUR Parcel
- ✓Your exact zone, not Long Hill's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Long Hill
Pull a site-specific report for your exact address in Long Hill, Connecticut — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Long Hill averages can't show:
We read public map data around Long Hill — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Long Hill average
How we know this about Long Hill
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 Long Hill’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 Long Hill
When does frost risk typically end in Long Hill?
The last hard freeze (28°F) in Long Hill typically lands around Mar 29, 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 19.
When is the first frost in Long Hill?
The first hard freeze (28°F) in Long Hill typically arrives around Nov 17, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 3, so the watching starts about Oct 18 — about 233 days after the spring freeze cleared.
How long is the growing season in Long Hill?
Measured between 28°F hard freezes, Long Hill sees about 233 frost-free days — roughly Mar 29 through Nov 17, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 19 to Nov 3, about 198 days.
Is the soil safe to grow vegetables in Long Hill?
The federal record around Long Hill is a meaningful one — 839 documented sites, mostly Underground Storage Tanks entries (444), the nearest Brownfields record about 0.2 miles 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 Long Hill?
From about Oct 18 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 17 (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 17. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Long Hill's scale — its 7a band and its 233-day season. Your yard writes its own version of Long Hill'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 Long Hill’s own scale
7 of the readings below were taken at Long Hill's own scale — its own ~233-day season between 28°F freezes, the 984 acres it covers and 839 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Long Hill's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Long Hill's own 28°F hard-freeze dates, about Mar 29 and Nov 17 and the ~233-day span between themNOAA 1991–2020 Climate Normals
- 839 documented contamination sites on the federal record near Long Hill, the closest Brownfields record about 0.2 miles out from the town centreFederal environmental registers
- Long Hill's boundary and the 984 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~233-day seasonGrowable Ground crop-matching engine
- The ecoregion at Long Hill's own centroid, the Northeastern Coastal ZoneUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Long Hilllydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Long Hill's 984 acres read through its county's SSURGO summaryfrom Southeastern Connecticut County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Southeastern Connecticut County
- The growing challenges every Connecticut grower plans around — written at state scale, so they stay on the state guidefrom Connecticut
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Southeastern Connecticut County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Long Hill's 984 acreswhy one lot differs from the next →
- Which side of Long Hill you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 984 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 Long Hill-wide figureread your own land →
More in Connecticut
Wider growing context
What grows across ConnecticutLong Hill sits outside our named growing regions, so Connecticut as a whole is its closest context here.
Nearby growing guides