New London, Connecticut, sits in USDA hardiness zone 7a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
Reliable performers under these conditions include cabbage, hazelnut, california poppy, and collard greens; what your own ground favors still comes down to its soil, sun, and drainage.
Even in New London, 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 New London 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 New London — soil, climate, flood, and parcel records. How we handle your address.
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New London — the short answer
New London, Connecticut: USDA zone 7a, about 233 days between hard freezes, across 4K acres of city.
- 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
- City area
- 4K 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 New London's average, not your lot's — a low corner or a tree line moves it. Against New London's 233-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in New London
Each reading below is measured for New London itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredNew London 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
MeasuredNew London 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 New London is in
New London sits in the Northeastern Coastal Zone — EPA Level III, inside the wider Eastern Temperate Forests. That is read at New London's own centroid rather than borrowed from Southeastern Connecticut Planning Region.
What Grows in New London
Every plant below cleared New London'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 New London?
Almost never — the real question is what to plant next. 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. With a season this long, “too late” mostly means “switch crops” — second sowings and a full fall garden are the norm, with garlic closing the year.
Documented around New London
Spotted lanternfly documented 14 miles from New London, first recorded 2022. What to watch for.
What's on the federal record near New London
Closest first, within ~10 miles of New London. Listing isn't leaking, and distance isn't exposure.
- R & R LANDSCAPINGBrownfields · 150 ft
- THAMESPORT MARINAUnderground Storage Tanks · 600 ft
- MITCHELL COLLEGEUnderground Storage Tanks · 1900 ft
- LAWRENCE MEMORIAL HOSPITALBrownfields · 2200 ft
- MESA FOODSBrownfields · 2400 ft
- PFIZER GLOBAL RESEARCH AND DEVELOPMENTUnderground Storage Tanks · 2500 ft
- LAWRENCE & MEMORIAL HOSPITALUnderground Storage Tanks · 2500 ft
- MITCHELL COLLEGEBrownfields · 2600 ft
- ELECTRIC BOAT NEW LONDON ENGINEERING COMPLEXBrownfields · 0.5 mi
- CT DEEPBrownfields · 0.6 mi
- Pump Station #2Underground Storage Tanks · 0.6 mi
- NEW LONDON WPCFUnderground Storage Tanks · 0.6 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from New London'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 New London.
Sources Checked
within ~10 miles of New London
Severity Distribution
within ~10 miles of New London
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around New London, Superfund runs higher than the national average — 17 sites within ~10 miles of New London. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in New London
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 New London average
Your land is one point inside New London
Everything above resolves to New London as a whole — one PHZM band and one 28°F frost record, read across 4K 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 city 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 New London Average
New London Average
- ●USDA Zones 7a, averaged across New London
- ●One soil character for all of New London
- ●Frost dates read at New London's scale: Mar 29 to Nov 17
YOUR Parcel
- ✓Your exact zone, not New London's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in New London
Pull a site-specific report for your exact address in New London, Connecticut — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that New London averages can't show:
We read public map data around New London — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the New London average
How we know this about New London
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read at this city’s own centroid; hard-freeze dates from NOAA 1991–2020 28°F normals at New London’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 city grain anywhere on this page — there is no city-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 New London
When does frost risk typically end in New London?
The last hard freeze (28°F) in New London 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 New London?
The first hard freeze (28°F) in New London 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 New London?
Measured between 28°F hard freezes, New London 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 New London?
The federal record around New London is a meaningful one — 823 documented sites, mostly Underground Storage Tanks entries (438), the nearest Brownfields record under a tenth of a mile 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 New London?
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 New London's scale — its 7a band and its 233-day season. Your yard writes its own version of New London'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 New London’s own scale
7 of the readings below were taken at New London's own scale — its own ~233-day season between 28°F freezes, the 3,588 acres it covers and 823 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- New London's own USDA hardiness band, zones 7aUSDA PHZM 2023
- New London's own 28°F hard-freeze dates, about Mar 29 and Nov 17 and the ~233-day span between themNOAA 1991–2020 Climate Normals
- 823 documented contamination sites on the federal record near New London, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- New London's boundary and the 3,588 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 New London's own centroid, the Northeastern Coastal ZoneUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of New Londonlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so New London's 3,588 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 New London's 3,588 acreswhy one lot differs from the next →
- Which side of New London you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 3,588 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record under a tenth of a mile 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 New London-wide figureread your own land →