Glenville, 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.
Crops well matched to these conditions include cabbage, hazelnut, california poppy, and collard greens — though what thrives on any one site still turns on its specific soil, sun, and drainage.
Even in Glenville, 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 Glenville 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 Glenville — soil, climate, flood, and parcel records. How we handle your address.
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Glenville — the short answer
Glenville, Connecticut: USDA zone 7a, about 240 days between hard freezes, across 480 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 23
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~240
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 480 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 Glenville's average, not your lot's — a low corner or a tree line moves it. Against Glenville's 240-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Glenville
Each reading below is measured for Glenville itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredGlenville runs about 240 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
MeasuredGlenville 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 Glenville is in
Glenville sits in the Northeastern Coastal Zone — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Glenville's own centroid rather than borrowed from Western Connecticut Planning Region.
What Grows in Glenville
Every plant below cleared Glenville's own zone 7a and its 240-day season. Each card opens that plant's Connecticut profile. How we score.
Is it too late to plant in Glenville?
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. 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 23 — long-season crops need about 90 days of runway, quick greens only 30. Here the season winds down slowly: late sowings, a real autumn harvest, and garlic in the ground before the first hard freeze.
Documented around Glenville
Spotted lanternfly documented 3 miles from Glenville, first recorded 2021. What to watch for.
What's on the federal record near Glenville
Closest first, within ~10 miles of Glenville. Listing isn't leaking, and distance isn't exposure.
- GLENVILLE FIRE STATIONUnderground Storage Tanks · 950 ft
- CNGBrownfields · 2300 ft
- BLIND BROOK HIGH SCHOOL-MIDDLEBrownfields · 2300 ft
- EXXONMOBIL OIL CORP SERV STA FEHBrownfields · 0.6 mi
- DOT CT STATE OFBrownfields · 0.6 mi
- EXXONMOBIL OIL CORP 81396Brownfields · 0.6 mi
- PORT REFINERYBrownfields · 0.7 mi
- PORT REFINERYSuperfund · 0.7 mi
- ANDERSON HILL ASBESTOS SITESuperfund · 1.3 mi
- GREENWICH METALS INC.Brownfields · 1.4 mi
- MIANUS FILTER PLANTUnderground Storage Tanks · 1.5 mi
- RUSTY OXER INC.Underground Storage Tanks · 1.5 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Glenville'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 Glenville.
Total Sites
1,359
within ~10 miles of Glenville
Risk Level
Elevated
Highest-severity
8 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of Glenville
Severity Distribution
within ~10 miles of Glenville
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Glenville, two things run higher than the national average within ~10 miles of Glenville — Brownfields (830 sites) and PFAS (14 sites). Knowing it is half the work — and it's nothing a thoughtful grower can't plan for.
Brownfields: Brownfield sites are former commercial or industrial properties where legacy soil contamination (heavy metals, PAHs, petroleum compounds) may persist.
PFAS: PFAS (per- and polyfluoroalkyl substances) are called "forever chemicals" because they do not biodegrade.
Check EPA brownfield remediation status — many sites have completed cleanup with institutional controls.
Test irrigation water source — this is the primary pathway for PFAS to reach garden crops.
Check your specific parcel in Glenville
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 Glenville average
Your land is one point inside Glenville
Everything above resolves to Glenville as a whole — one PHZM band and one 28°F frost record, read across 480 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 Glenville Average
Glenville Average
- ●USDA Zones 7a, averaged across Glenville
- ●One soil character for all of Glenville
- ●Frost dates read at Glenville's scale: Mar 28 to Nov 23
YOUR Parcel
- ✓Your exact zone, not Glenville's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Glenville
Pull a site-specific report for your exact address in Glenville, Connecticut — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Glenville averages can't show:
We read public map data around Glenville — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Glenville average
How we know this about Glenville
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 Glenville’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 Glenville
When does frost risk typically end in Glenville?
The last hard freeze (28°F) in Glenville 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 Glenville?
The first hard freeze (28°F) in Glenville typically arrives around Nov 23, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Nov 9, so the watching starts about Oct 24 — about 240 days after the spring freeze cleared.
How long is the growing season in Glenville?
Measured between 28°F hard freezes, Glenville sees about 240 frost-free days — roughly Mar 28 through Nov 23, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 18 to Nov 9, about 205 days.
Is the soil safe to grow vegetables in Glenville?
The federal record around Glenville is a meaningful one — 1,359 documented sites, mostly Brownfields entries (830), the nearest Underground Storage Tanks record about 0.2 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 Glenville?
From about Oct 24 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 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 Nov 23. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Glenville's scale — its 7a band and its 240-day season. Your yard writes its own version of Glenville'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 Glenville’s own scale
7 of the readings below were taken at Glenville's own scale — its own ~240-day season between 28°F freezes, the 480 acres it covers and 1,359 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Glenville's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Glenville's own 28°F hard-freeze dates, about Mar 28 and Nov 23 and the ~240-day span between themNOAA 1991–2020 Climate Normals
- 1,359 documented contamination sites on the federal record near Glenville, the closest Underground Storage Tanks record about 0.2 miles out from the town centreFederal environmental registers
- Glenville's boundary and the 480 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~240-day seasonGrowable Ground crop-matching engine
- The ecoregion at Glenville's own centroid, the Northeastern Coastal ZoneUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Glenvillelydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Glenville's 480 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 Glenville's 480 acreswhy one lot differs from the next →
- Which side of Glenville you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 480 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Underground Storage Tanks record about 0.2 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 Glenville-wide figureread your own land →
More in Connecticut
Wider growing context
What grows across ConnecticutGlenville sits outside our named growing regions, so Connecticut as a whole is its closest context here.
Nearby growing guides