Groton, Massachusetts, sits in USDA hardiness zone 6a — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
On paper, cabbage, hazelnut, lavender, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
You’re in Greater Boston
The state's dense urban core, where growing means raised beds, community plots, and back-lot kitchen gardens more than open field. A long, mild season for the region — but city soil is the thing to know before you dig.
Even in Groton, 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 Groton 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 Groton — soil, climate, flood, and parcel records. How we handle your address.
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Groton — the short answer
Groton, Massachusetts: USDA zone 6a, about 191 days between hard freezes, across 1K acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 14
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 22
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~191
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 1K 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 6a is Groton's average, not your lot's — a low corner or a tree line moves it. Against Groton's 191-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Groton
Each reading below is measured for Groton itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredGroton runs about 191 days between hard freezes — a moderate growing season.
There is room for the full run of cool-season crops plus a warm-season main crop, but the calendar is tight enough that a late spring or early fall frost still decides how much finishes.
Time warm-season transplants to your last hard freeze, and a few weeks of season extension turns a near-miss harvest into a sure one.
NOAA 1991–2020 Climate Normals
Winter hardiness
MeasuredGroton sits in USDA hardiness zone 6a.
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 Groton is in
Groton sits in the Northeastern Coastal Zone — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Groton's own centroid rather than borrowed from Middlesex County.
What Grows in Groton
Every plant below cleared Groton's own zone 6a and its 191-day season. Each card opens that plant's Massachusetts profile. How we score.
Is it too late to plant in Groton?
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 17; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 14 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 22 — long-season crops need about 90 days of runway, quick greens only 30. The tail of the season still works: sixty-day crops into late summer, quick greens after, garlic last of all.
Documented around Groton
Spotted lanternfly documented 8 miles from Groton, first recorded 2022. What to watch for.
What's on the federal record near Groton
Closest first, within ~10 miles of Groton. Listing isn't leaking, and distance isn't exposure.
- GROTON WATER DEPARTMENTPFAS · 25 ft
- GIBBET HILL FARMUnderground Storage Tanks · 2200 ft
- BUCKINGHAM BUS CO INCBrownfields · 2400 ft
- BUCKINGHAM BUS CO INCUnderground Storage Tanks · 2400 ft
- JOHNNY'S TEXACOUnderground Storage Tanks · 0.5 mi
- GROTON SERVICE CENTERBrownfields · 0.6 mi
- LAWRENCE ACADEMYBrownfields · 0.6 mi
- PLATT BUILDERS INCBrownfields · 0.6 mi
- HEG #3120Underground Storage Tanks · 0.7 mi
- ENERGY NORTH INC 3120Brownfields · 0.7 mi
- FLORENCE ROCHE ELEMENTARY SCHOOLBrownfields · 0.7 mi
- SEVEN HILLS PEDIATRIC CENTERBrownfields · 0.8 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Groton'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 Groton.
Sources Checked
within ~10 miles of Groton
Severity Distribution
within ~10 miles of Groton
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Groton, two things run higher than the national average within ~10 miles of Groton — PFAS (12 sites) and Superfund (15 sites). That's not a problem with your land — it's information about it.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Check your specific parcel in Groton
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 Groton average
Your land is one point inside Groton
Everything above resolves to Groton as a whole — one PHZM band and one 28°F frost record, read across 1K 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 Groton Average
Groton Average
- ●USDA Zones 6a, averaged across Groton
- ●One soil character for all of Groton
- ●Frost dates read at Groton's scale: Apr 14 to Oct 22
YOUR Parcel
- ✓Your exact zone, not Groton's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Groton
Pull a site-specific report for your exact address in Groton, Massachusetts — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Groton averages can't show:
We read public map data around Groton — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Groton average
How we know this about Groton
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 Groton’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 Groton
When does frost risk typically end in Groton?
The last hard freeze (28°F) in Groton typically lands around Apr 14, 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 May 5.
When is the first frost in Groton?
The first hard freeze (28°F) in Groton typically arrives around Oct 22, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 8, so the watching starts about Sep 22 — about 191 days after the spring freeze cleared.
How long is the growing season in Groton?
Measured between 28°F hard freezes, Groton sees about 191 frost-free days — roughly Apr 14 through Oct 22, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 5 to Oct 8, about 156 days.
Is the soil safe to grow vegetables in Groton?
The federal record around Groton runs heavier than most — 941 documented sites, mostly Brownfields entries (564), the nearest PFAS record under a tenth of a mile 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 Groton?
From about Sep 22 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 Oct 22 (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 Oct 22. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Groton's scale — its 6a band and its 191-day season. Your yard writes its own version of Groton'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 Groton’s own scale
7 of the readings below were taken at Groton's own scale — its own ~191-day season between 28°F freezes, the 1,070 acres it covers and 941 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Groton's own USDA hardiness band, zones 6aUSDA PHZM 2023
- Groton's own 28°F hard-freeze dates, about Apr 14 and Oct 22 and the ~191-day span between themNOAA 1991–2020 Climate Normals
- 941 documented contamination sites on the federal record near Groton, the closest PFAS record under a tenth of a mile out from the town centreFederal environmental registers
- Groton's boundary and the 1,070 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~191-day seasonGrowable Ground crop-matching engine
- The ecoregion at Groton's own centroid, the Northeastern Coastal ZoneUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Grotonlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Groton's 1,070 acres read through its county's SSURGO summaryfrom Middlesex County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Middlesex County
- The growing challenges every Massachusetts grower plans around — written at state scale, so they stay on the state guidefrom Massachusetts
- Butterfly and beetle records, and the farmland pesticide estimate — all published county-widefrom Middlesex County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Groton's 1,070 acreswhy one lot differs from the next →
- Which side of Groton you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,070 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest PFAS 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 Groton-wide figureread your own land →
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