Blue Hills, Connecticut, sits in USDA hardiness zone 6b — a zone band wide enough that plant choice, not possibility, is the interesting question.
Expect cabbage, hazelnut, lavender, and collard greens to be strong candidates here; the deciding factors on any one parcel stay local — soil, sun, and drainage.
Even in Blue Hills, 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 Blue Hills 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 Blue Hills — soil, climate, flood, and parcel records. How we handle your address.
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Blue Hills — the short answer
Blue Hills, Connecticut: USDA zone 6b, about 214 days between hard freezes, across 746 acres of town.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 2
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 2
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~214
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 746 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 6b is Blue Hills's average, not your lot's — a low corner or a tree line moves it. Against Blue Hills's 214-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Blue Hills
Each reading below is measured for Blue Hills itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredBlue Hills runs about 214 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
MeasuredBlue Hills sits in USDA hardiness zone 6b.
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 Blue Hills is in
Blue Hills sits in the Northeastern Coastal Zone — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Blue Hills's own centroid rather than borrowed from Capitol Planning Region.
What Grows in Blue Hills
Every plant below cleared Blue Hills's own zone 6b and its 214-day season. Each card opens that plant's Connecticut profile. How we score.
Is it too late to plant in Blue Hills?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 5; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 2 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 2 — 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 Blue Hills
Spotted lanternfly documented 5 miles from Blue Hills, first recorded 2022. What to watch for.
What's on the federal record near Blue Hills
Closest first, within ~10 miles of Blue Hills. Listing isn't leaking, and distance isn't exposure.
- C-THRU RULERBrownfields · 550 ft
- SUNOCO SERVICE STABrownfields · 650 ft
- Advanced Gas Company, Inc. (Citgo)Underground Storage Tanks · 950 ft
- SELF SERVICE SALESUnderground Storage Tanks · 1700 ft
- MOBILUnderground Storage Tanks · 1700 ft
- ADVANCE AUTO PARTS #8943Brownfields · 2400 ft
- SWIFT TEXTILE METALIZING LLCBrownfields · 2600 ft
- ARTEFFECTS INCBrownfields · 0.6 mi
- FIREHOUSE, #16Underground Storage Tanks · 0.6 mi
- FRED'S ONE HOUR CLEANERSBrownfields · 0.6 mi
- GROTE & WEIGEL, INC.Underground Storage Tanks · 0.7 mi
- MERCURY CLEANERS OF HARTFORD INCBrownfields · 0.7 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Blue Hills'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 Blue Hills.
Total Sites
3,002
within ~10 miles of Blue Hills
Risk Level
Elevated
Highest-severity
29 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Blue Hills
Severity Distribution
within ~10 miles of Blue Hills
Highest-Severity Sites
Know Before You Grow
- •Underground tanks leak petroleum as they age — near a former filling station, test the soil.
- •Near a brownfield, raised beds of imported soil give your food clean ground.
- •On a private well, test for nitrates: above 10 mg/L the water needs treatment before irrigating.
Check your specific parcel in Blue Hills
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 Blue Hills average
Your land is one point inside Blue Hills
Everything above resolves to Blue Hills as a whole — one PHZM band and one 28°F frost record, read across 746 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 Blue Hills Average
Blue Hills Average
- ●USDA Zones 6b, averaged across Blue Hills
- ●One soil character for all of Blue Hills
- ●Frost dates read at Blue Hills's scale: Apr 2 to Nov 2
YOUR Parcel
- ✓Your exact zone, not Blue Hills's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Blue Hills
Pull a site-specific report for your exact address in Blue Hills, Connecticut — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Blue Hills averages can't show:
We read public map data around Blue Hills — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Blue Hills average
How we know this about Blue Hills
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 Blue Hills’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 Blue Hills
When does frost risk typically end in Blue Hills?
The last hard freeze (28°F) in Blue Hills typically lands around Apr 2, 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 23.
When is the first frost in Blue Hills?
The first hard freeze (28°F) in Blue Hills typically arrives around Nov 2, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 19, so the watching starts about Oct 3 — about 214 days after the spring freeze cleared.
How long is the growing season in Blue Hills?
Measured between 28°F hard freezes, Blue Hills sees about 214 frost-free days — roughly Apr 2 through Nov 2, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 23 to Oct 19, about 179 days.
Is the soil safe to grow vegetables in Blue Hills?
The federal record around Blue Hills is a meaningful one — 3,002 documented sites, mostly Underground Storage Tanks entries (1,525), the nearest Brownfields record about 0.1 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 Blue Hills?
From about Oct 3 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 2 (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 2. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Blue Hills's scale — its 6b band and its 214-day season. Your yard writes its own version of Blue Hills'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 Blue Hills’s own scale
7 of the readings below were taken at Blue Hills's own scale — its own ~214-day season between 28°F freezes, the 746 acres it covers and 3,002 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Blue Hills's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Blue Hills's own 28°F hard-freeze dates, about Apr 2 and Nov 2 and the ~214-day span between themNOAA 1991–2020 Climate Normals
- 3,002 documented contamination sites on the federal record near Blue Hills, the closest Brownfields record about 0.1 miles out from the town centreFederal environmental registers
- Blue Hills's boundary and the 746 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~214-day seasonGrowable Ground crop-matching engine
- The ecoregion at Blue Hills's own centroid, the Northeastern Coastal ZoneUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Blue Hillslydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Blue Hills's 746 acres read through its county's SSURGO summaryfrom Capitol County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Capitol 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 Capitol County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Blue Hills's 746 acreswhy one lot differs from the next →
- Which side of Blue Hills you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 746 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.1 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 Blue Hills-wide figureread your own land →