Sail Harbor, Connecticut, sits in USDA hardiness zone 6b — enough range to grow cool-season vegetables, hardy fruit, and warm-season crops that mature before the first hard frost.
On paper, cabbage, blackberry, california poppy, and collard greens all suit these conditions — on the ground, soil, sun, and drainage make the final call.
Even in Sail Harbor, 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 Sail Harbor 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 Sail Harbor — soil, climate, flood, and parcel records. How we handle your address.
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Sail Harbor — the short answer
Sail Harbor, Connecticut: USDA zone 6b, about 189 days between hard freezes, across 300 acres of town.
- USDA zone
- 6b
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 17
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 23
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~189
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 300 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 Sail Harbor's average, not your lot's — a low corner or a tree line moves it. Against Sail Harbor's 189-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Sail Harbor
Each reading below is measured for Sail Harbor itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredSail Harbor runs about 189 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
MeasuredSail Harbor 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 Sail Harbor is in
Sail Harbor sits in the Northeastern Highlands — EPA Level III, inside the wider Northern Forests. That is read at Sail Harbor's own centroid rather than borrowed from Western Connecticut Planning Region.
What Grows in Sail Harbor
Every plant below cleared Sail Harbor's own zone 6b and its 189-day season. Each card opens that plant's Connecticut profile. How we score.
Is it too late to plant in Sail Harbor?
Usually not — gardeners here simply switch what goes in the ground as the season moves. Cool-season crops can go in from around Mar 20; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 17 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 23 — 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 Sail Harbor
Spotted lanternfly documented 3 miles from Sail Harbor, first recorded 2022. What to watch for.
What's on the federal record near Sail Harbor
Closest first, within ~10 miles of Sail Harbor. Listing isn't leaking, and distance isn't exposure.
- BOGUS HILL COMMUNITYBrownfields · 1.1 mi
- CT-SHM 5Nitrate · 1.5 mi
- CT-NMI 29Nitrate · 1.6 mi
- CT-SHM 6Nitrate · 1.8 mi
- TODD R. SMITHUnderground Storage Tanks · 2.1 mi
- ODIF USABrownfields · 2.1 mi
- Cumberland Farms #820Underground Storage Tanks · 2.1 mi
- NEW MILFORD HIGH SCHOOLUnderground Storage Tanks · 2.1 mi
- CUMBERLAND FARMS 4769/0820Brownfields · 2.1 mi
- Former Valley Marble PropertyUnderground Storage Tanks · 2.2 mi
- CT-NMI 14Nitrate · 2.2 mi
- Raos CitgoUnderground Storage Tanks · 2.2 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Sail Harbor'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 Sail Harbor.
Total Sites
902
within ~10 miles of Sail Harbor
Risk Level
Elevated
Highest-severity
12 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Sail Harbor
Severity Distribution
within ~10 miles of Sail Harbor
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Sail Harbor, Superfund runs higher than the national average — 12 sites within ~10 miles of Sail Harbor. 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 Sail Harbor
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 Sail Harbor average
Your land is one point inside Sail Harbor
Everything above resolves to Sail Harbor as a whole — one PHZM band and one 28°F frost record, read across 300 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 Sail Harbor Average
Sail Harbor Average
- ●USDA Zones 6b, averaged across Sail Harbor
- ●One soil character for all of Sail Harbor
- ●Frost dates read at Sail Harbor's scale: Apr 17 to Oct 23
YOUR Parcel
- ✓Your exact zone, not Sail Harbor's 6b
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Sail Harbor
Pull a site-specific report for your exact address in Sail Harbor, Connecticut — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Sail Harbor averages can't show:
We read public map data around Sail Harbor — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Sail Harbor average
How we know this about Sail Harbor
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 Sail Harbor’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 Sail Harbor
When does frost risk typically end in Sail Harbor?
The last hard freeze (28°F) in Sail Harbor typically lands around Apr 17, 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 8.
When is the first frost in Sail Harbor?
The first hard freeze (28°F) in Sail Harbor typically arrives around Oct 23, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 9, so the watching starts about Sep 23 — about 189 days after the spring freeze cleared.
How long is the growing season in Sail Harbor?
Measured between 28°F hard freezes, Sail Harbor sees about 189 frost-free days — roughly Apr 17 through Oct 23, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 8 to Oct 9, about 154 days.
Is the soil safe to grow vegetables in Sail Harbor?
The federal record around Sail Harbor is a meaningful one — 902 documented sites, mostly Underground Storage Tanks entries (464), the nearest Brownfields record about 1.1 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 Sail Harbor?
From about Sep 23 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 23 (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 23. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Sail Harbor's scale — its 6b band and its 189-day season. Your yard writes its own version of Sail Harbor'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 Sail Harbor’s own scale
7 of the readings below were taken at Sail Harbor's own scale — its own ~189-day season between 28°F freezes, the 300 acres it covers and 902 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Sail Harbor's own USDA hardiness band, zones 6bUSDA PHZM 2023
- Sail Harbor's own 28°F hard-freeze dates, about Apr 17 and Oct 23 and the ~189-day span between themNOAA 1991–2020 Climate Normals
- 902 documented contamination sites on the federal record near Sail Harbor, the closest Brownfields record about 1.1 miles out from the town centreFederal environmental registers
- Sail Harbor's boundary and the 300 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6b and a ~189-day seasonGrowable Ground crop-matching engine
- The ecoregion at Sail Harbor's own centroid, the Northeastern HighlandsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Sail Harborlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Sail Harbor's 300 acres read through its county's SSURGO summaryfrom Western Connecticut County
- Growing-degree days and winter chill — measured county-wide only, so the county page carries themfrom Western 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 Western Connecticut County
What this page can’t tell you
- The soil pH, drainage, sun hours, and frost pockets on any one lot among Sail Harbor's 300 acreswhy one lot differs from the next →
- Which side of Sail Harbor you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 300 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 1.1 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 Sail Harbor-wide figureread your own land →
More in Connecticut
Wider growing context
What grows across ConnecticutSail Harbor sits outside our named growing regions, so Connecticut as a whole is its closest context here.
Nearby growing guides