Darien Downtown, Connecticut, sits in USDA hardiness zone 7a — a band that supports both cool-season staples and warm-season crops chosen to fit the local frost window.
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 Darien Downtown, 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 Darien Downtown 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 Darien Downtown — soil, climate, flood, and parcel records. How we handle your address.
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Darien Downtown — the short answer
Darien Downtown, Connecticut: USDA zone 7a, about 239 days between hard freezes, across 504 acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 28
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 22
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~239
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 504 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 Darien Downtown's average, not your lot's — a low corner or a tree line moves it. Against Darien Downtown's 239-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Darien Downtown
Each reading below is measured for Darien Downtown itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredDarien Downtown runs about 239 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
MeasuredDarien Downtown 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 Darien Downtown is in
Darien Downtown sits in the Northeastern Coastal Zone — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Darien Downtown's own centroid rather than borrowed from Western Connecticut Planning Region.
What Grows in Darien Downtown
Every plant below cleared Darien Downtown's own zone 7a and its 239-day season. Each card opens that plant's Connecticut profile. How we score.
Is it too late to plant in Darien Downtown?
Rarely: the season closes in stages, not all at once, and each stage has its crops. Cool-season crops can go in from around Feb 28; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 28 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 22 — long-season crops need about 90 days of runway, quick greens only 30. There is slack in a calendar like this — late plantings, second rounds of favorites, and a fall bench that keeps beds working.
Documented around Darien Downtown
Spotted lanternfly documented 3 miles from Darien Downtown, first recorded 2021. What to watch for.
What's on the federal record near Darien Downtown
Closest first, within ~10 miles of Darien Downtown. Listing isn't leaking, and distance isn't exposure.
- 9 VILLAGE CLEANERSBrownfields · 150 ft
- CHARKIT CHEMICAL CORPToxics Release Inventory · 300 ft
- CVS PHARMACY 0918Brownfields · 400 ft
- CT/DOT DARIEN RR STATIONBrownfields · 800 ft
- ALLIANCE ENERGYBrownfields · 900 ft
- DARIEN AUTO SPECIALISTS INC.Underground Storage Tanks · 950 ft
- ROTHENBERG & BRAUN DRSBrownfields · 1000 ft
- DARIEN LAUNDERETTEBrownfields · 1200 ft
- STOP & SHOPBrownfields · 1200 ft
- 719 BOSTON POST RDBrownfields · 1500 ft
- HENKEL CORPORATIONBrownfields · 1700 ft
- EXXONMOBIL OIL CORP 14037Brownfields · 0.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Darien Downtown'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 Darien Downtown.
Total Sites
1,383
within ~10 miles of Darien Downtown
Risk Level
Elevated
Highest-severity
14 Superfund sites
Sources Checked
within ~10 miles of Darien Downtown
Severity Distribution
within ~10 miles of Darien Downtown
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 Darien Downtown
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 Darien Downtown average
Your land is one point inside Darien Downtown
Everything above resolves to Darien Downtown as a whole — one PHZM band and one 28°F frost record, read across 504 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 Darien Downtown Average
Darien Downtown Average
- ●USDA Zones 7a, averaged across Darien Downtown
- ●One soil character for all of Darien Downtown
- ●Frost dates read at Darien Downtown's scale: Mar 28 to Nov 22
YOUR Parcel
- ✓Your exact zone, not Darien Downtown's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Darien Downtown
Pull a site-specific report for your exact address in Darien Downtown, Connecticut — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Darien Downtown averages can't show:
We read public map data around Darien Downtown — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Darien Downtown average
How we know this about Darien Downtown
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 Darien Downtown’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 Darien Downtown
When does frost risk typically end in Darien Downtown?
The last hard freeze (28°F) in Darien Downtown typically lands around Mar 28, 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 18.
When is the first frost in Darien Downtown?
The first hard freeze (28°F) in Darien Downtown typically arrives around Nov 22, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 8, so the watching starts about Oct 23 — about 239 days after the spring freeze cleared.
How long is the growing season in Darien Downtown?
Measured between 28°F hard freezes, Darien Downtown sees about 239 frost-free days — roughly Mar 28 through Nov 22, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 18 to Nov 8, about 204 days.
Is the soil safe to grow vegetables in Darien Downtown?
The federal record around Darien Downtown is a meaningful one — 1,383 documented sites, mostly Underground Storage Tanks entries (717), 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 Darien Downtown?
From about Oct 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 Nov 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 Nov 22. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Darien Downtown's scale — its 7a band and its 239-day season. Your yard writes its own version of Darien Downtown'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 Darien Downtown’s own scale
7 of the readings below were taken at Darien Downtown's own scale — its own ~239-day season between 28°F freezes, the 504 acres it covers and 1,383 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Darien Downtown's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Darien Downtown's own 28°F hard-freeze dates, about Mar 28 and Nov 22 and the ~239-day span between themNOAA 1991–2020 Climate Normals
- 1,383 documented contamination sites on the federal record near Darien Downtown, the closest Brownfields record under a tenth of a mile out from the town centreFederal environmental registers
- Darien Downtown's boundary and the 504 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~239-day seasonGrowable Ground crop-matching engine
- The ecoregion at Darien Downtown's own centroid, the Northeastern Coastal ZoneUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Darien Downtownlydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Darien Downtown's 504 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 Darien Downtown's 504 acreswhy one lot differs from the next →
- Which side of Darien Downtown you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 504 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 Darien Downtown-wide figureread your own land →
More in Connecticut
Wider growing context
What grows across ConnecticutDarien Downtown sits outside our named growing regions, so Connecticut as a whole is its closest context here.
Nearby growing guides