Old Hill, 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.
A short list that earns its place here — cabbage, hazelnut, california poppy, and collard greens — with any one site's soil, sun, and drainage making the final cut.
Even in Old Hill, 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 Old Hill 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 Old Hill — soil, climate, flood, and parcel records. How we handle your address.
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Old Hill — the short answer
Old Hill, Connecticut: USDA zone 7a, about 225 days between hard freezes, across 1K acres of town.
- USDA zone
- 7a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Mar 31
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Nov 11
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~225
- 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 7a is Old Hill's average, not your lot's — a low corner or a tree line moves it. Against Old Hill's 225-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in Old Hill
Each reading below is measured for Old Hill itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredOld Hill runs about 225 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
MeasuredOld Hill 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 Old Hill is in
Old Hill sits in the Northeastern Coastal Zone — EPA Level III, inside the wider Eastern Temperate Forests. That is read at Old Hill's own centroid rather than borrowed from Western Connecticut Planning Region.
What Grows in Old Hill
Every plant below cleared Old Hill's own zone 7a and its 225-day season. Each card opens that plant's Connecticut profile. How we score.
Is it too late to plant in Old Hill?
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 Mar 3; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Mar 31 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Nov 11 — 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 Old Hill
Spotted lanternfly documented 2 miles from Old Hill, first recorded 2021. What to watch for.
What's on the federal record near Old Hill
Closest first, within ~10 miles of Old Hill. Listing isn't leaking, and distance isn't exposure.
- EARTHPLACEBrownfields · 1700 ft
- CT-NW 20Nitrate · 0.6 mi
- 19 NEWTOWN TURNPIKEUnderground Storage Tanks · 0.7 mi
- CT-WP 11Nitrate · 0.7 mi
- CT-WP 12Nitrate · 0.7 mi
- CT-WP 10Nitrate · 0.7 mi
- IMAGE WORKSBrownfields · 0.8 mi
- CT-WP 9Nitrate · 0.8 mi
- CT-WP 33Nitrate · 0.8 mi
- AQUARION WATER COMPANYBrownfields · 0.8 mi
- CRANBURY SERVICE STATION LLCUnderground Storage Tanks · 0.8 mi
- COMMUNITY DRY CLEANERSBrownfields · 0.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from Old Hill'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 Old Hill.
Sources Checked
within ~10 miles of Old Hill
Severity Distribution
within ~10 miles of Old Hill
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Old Hill, Superfund runs higher than the national average — 17 sites within ~10 miles of Old Hill. That's not a problem with your land — it's information about 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 Old Hill
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 Old Hill average
Your land is one point inside Old Hill
Everything above resolves to Old Hill 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 Old Hill Average
Old Hill Average
- ●USDA Zones 7a, averaged across Old Hill
- ●One soil character for all of Old Hill
- ●Frost dates read at Old Hill's scale: Mar 31 to Nov 11
YOUR Parcel
- ✓Your exact zone, not Old Hill's 7a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in Old Hill
Pull a site-specific report for your exact address in Old Hill, Connecticut — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that Old Hill averages can't show:
We read public map data around Old Hill — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Old Hill average
How we know this about Old Hill
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 Old Hill’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 Old Hill
When does frost risk typically end in Old Hill?
The last hard freeze (28°F) in Old Hill typically lands around Mar 31, 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 21.
When is the first frost in Old Hill?
The first hard freeze (28°F) in Old Hill typically arrives around Nov 11, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 28, so the watching starts about Oct 12 — about 225 days after the spring freeze cleared.
How long is the growing season in Old Hill?
Measured between 28°F hard freezes, Old Hill sees about 225 frost-free days — roughly Mar 31 through Nov 11, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer Apr 21 to Oct 28, about 190 days.
Is the soil safe to grow vegetables in Old Hill?
The federal record around Old Hill is a meaningful one — 1,287 documented sites, mostly Underground Storage Tanks entries (574), the nearest Brownfields record about 0.3 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 Old Hill?
From about Oct 12 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 11 (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 11. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at Old Hill's scale — its 7a band and its 225-day season. Your yard writes its own version of Old Hill'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 Old Hill’s own scale
7 of the readings below were taken at Old Hill's own scale — its own ~225-day season between 28°F freezes, the 1,382 acres it covers and 1,287 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- Old Hill's own USDA hardiness band, zones 7aUSDA PHZM 2023
- Old Hill's own 28°F hard-freeze dates, about Mar 31 and Nov 11 and the ~225-day span between themNOAA 1991–2020 Climate Normals
- 1,287 documented contamination sites on the federal record near Old Hill, the closest Brownfields record about 0.3 miles out from the town centreFederal environmental registers
- Old Hill's boundary and the 1,382 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 7a and a ~225-day seasonGrowable Ground crop-matching engine
- The ecoregion at Old Hill's own centroid, the Northeastern Coastal ZoneUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of Old Hilllydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so Old Hill's 1,382 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 Old Hill's 1,382 acreswhy one lot differs from the next →
- Which side of Old Hill you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 1,382 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Brownfields record about 0.3 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 Old Hill-wide figureread your own land →
More in Connecticut
Wider growing context
What grows across ConnecticutOld Hill sits outside our named growing regions, so Connecticut as a whole is its closest context here.
Nearby growing guides