North Granby, Connecticut, sits in USDA hardiness zone 6a — room for a real mix of vegetables, fruit, and perennials matched to the local frost calendar.
Well-matched crops include cabbage, hazelnut, lavender, and collard greens, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Even in North Granby, 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 North Granby 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 North Granby — soil, climate, flood, and parcel records. How we handle your address.
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North Granby — the short answer
North Granby, Connecticut: USDA zone 6a, about 196 days between hard freezes, across 5K acres of town.
- USDA zone
- 6a
- USDA PHZM 2023
- Last hard freeze (28°F)
- Apr 13
- NOAA 1991–2020 Climate Normals, 28°F — this town
- First hard freeze (28°F)
- Oct 26
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Days between freezes
- ~196
- NOAA 1991–2020 Climate Normals, 28°F — this town
- Town area
- 5K 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 6a is North Granby's average, not your lot's — a low corner or a tree line moves it. Against North Granby's 196-day season, see what your own ground reads.
Soil varies lot by lot — soil types explained.
What this means for growing in North Granby
Each reading below is measured for North Granby itself — here is what it means for a garden here, and the move an experienced grower makes about it.
Season length
MeasuredNorth Granby runs about 196 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
MeasuredNorth Granby sits in USDA hardiness zone 6a.
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 North Granby is in
North Granby sits in the Northeastern Highlands — EPA Level III, inside the wider Northern Forests. That is read at North Granby's own centroid rather than borrowed from Capitol Planning Region.
What Grows in North Granby
Every plant below cleared North Granby's own zone 6a and its 196-day season. Each card opens that plant's Connecticut profile. How we score.
Is it too late to plant in North Granby?
For most of the year, no — what changes is which crops still fit the days remaining. Cool-season crops can go in from around Mar 16; tender transplants wait until two to three weeks after the last 28°F hard freeze, which lands near Apr 13 (NOAA 1991–2020 climate normals); and from midsummer, planting counts back from the first fall freeze around Oct 26 — long-season crops need about 90 days of runway, quick greens only 30. Even past midsummer there is room for a true fall garden here, and garlic planted near the close carries the momentum into next year.
Documented around North Granby
Spotted lanternfly documented 11 miles from North Granby, first recorded 2022. What to watch for.
What's on the federal record near North Granby
Closest first, within ~10 miles of North Granby. Listing isn't leaking, and distance isn't exposure.
- CT-GR 18Nitrate · 1.1 mi
- LOST ACRES ORCHARDUnderground Storage Tanks · 1.2 mi
- SHAWS GARAGEUnderground Storage Tanks · 1.2 mi
- CT-GR 97Nitrate · 1.3 mi
- CT-GR 314Nitrate · 1.5 mi
- CT-GR 267Nitrate · 1.5 mi
- JAKE ENTERPRISES INCUnderground Storage Tanks · 2.1 mi
- ROCKWOOD FARM ORGANIC RECYCLERYBrownfields · 2.2 mi
- WACKERBARTH BOX SHOP INCUnderground Storage Tanks · 2.6 mi
- GIRROIR BROS INCBrownfields · 2.6 mi
- ARROW CONCRETE PRODUCTS INCUnderground Storage Tanks · 2.8 mi
- TILCON CONNECTICUT INC.Underground Storage Tanks · 2.9 mi
6 more sites are on the record inside the same radius. See them on the map
Measured from North Granby'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 North Granby.
Total Sites
649
within ~10 miles of North Granby
Risk Level
Elevated
Highest-severity
7 Superfund sites (none NPL-listed)
Sources Checked
within ~10 miles of North Granby
Severity Distribution
within ~10 miles of North Granby
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 North Granby
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 North Granby average
Your land is one point inside North Granby
Everything above resolves to North Granby as a whole — one PHZM band and one 28°F frost record, read across 5K 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 North Granby Average
North Granby Average
- ●USDA Zones 6a, averaged across North Granby
- ●One soil character for all of North Granby
- ●Frost dates read at North Granby's scale: Apr 13 to Oct 26
YOUR Parcel
- ✓Your exact zone, not North Granby's 6a
- ✓Your SSURGO soil type & pH
- ✓Your sun exposure, cast in 3D
See MY Growing Report
Read your specific parcel in North Granby
Pull a site-specific report for your exact address in North Granby, Connecticut — soil, sun, drainage, frost risk, and scored plant recommendations.
Three things about your lot that North Granby averages can't show:
We read public map data around North Granby — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the North Granby average
How we know this about North Granby
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 North Granby’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 North Granby
When does frost risk typically end in North Granby?
The last hard freeze (28°F) in North Granby typically lands around Apr 13, 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 4.
When is the first frost in North Granby?
The first hard freeze (28°F) in North Granby typically arrives around Oct 26, per NOAA 1991–2020 climate normals — the point tender summer crops finish. Lighter frosts run ahead of it, near Oct 12, so the watching starts about Sep 26 — about 196 days after the spring freeze cleared.
How long is the growing season in North Granby?
Measured between 28°F hard freezes, North Granby sees about 196 frost-free days — roughly Apr 13 through Oct 26, per NOAA 1991–2020 climate normals. Tender crops work a shorter one: nearer May 4 to Oct 12, about 161 days.
Is the soil safe to grow vegetables in North Granby?
The federal record around North Granby is a meaningful one — 649 documented sites, mostly Underground Storage Tanks entries (254), the nearest Nitrate 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 North Granby?
From about Sep 26 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 26 (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 26. Hardy greens and roots shrug off light frost and sweeten after it — leave them in.
Everything above is measured at North Granby's scale — its 6a band and its 196-day season. Your yard writes its own version of North Granby'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 North Granby’s own scale
7 of the readings below were taken at North Granby's own scale — its own ~196-day season between 28°F freezes, the 5,339 acres it covers and 649 documented sites around it; 4 are borrowed from a wider read, named and linked below.
Measured here
- North Granby's own USDA hardiness band, zones 6aUSDA PHZM 2023
- North Granby's own 28°F hard-freeze dates, about Apr 13 and Oct 26 and the ~196-day span between themNOAA 1991–2020 Climate Normals
- 649 documented contamination sites on the federal record near North Granby, the closest Nitrate record about 1.1 miles out from the town centreFederal environmental registers
- North Granby's boundary and the 5,339 acres inside itUS Census TIGER/Line 2025
- Which of 1,086 plants clear zones 6a and a ~196-day seasonGrowable Ground crop-matching engine
- The ecoregion at North Granby's own centroid, the Northeastern HighlandsUS EPA Level III Ecoregions
- A documented spotted-lanternfly record within reach of North Granbylydemapr (De Bona & Helmus), 10 km survey lattice
Inherited from a wider read
- Soil character — no town-scale survey exists, so North Granby's 5,339 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 North Granby's 5,339 acreswhy one lot differs from the next →
- Which side of North Granby you're on — a low spot frosts first and a south wall warms early, and one normal is being asked to speak for all 5,339 acresreading your own microclimate →
- How close that record sits to YOUR lot — the closest Nitrate 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 North Granby-wide figureread your own land →