Connecticut spans USDA hardiness zones 6a-7b, with a growing season of about 207 frost-free days — a season with slack in it: successions, late sowings, and long-maturing crops all fit.
In practice the season is written by 44-52 inches of annual rainfall, a median of roughly 2,664 growing-degree days (base 50°F), and about 2,500 winter chill hours for tree fruit. Dig almost anywhere and you'll meet glacial till, sandy loam, and river valley silt; how quickly they shed water is the first thing to learn about them. Connecticut splits into distinct growing country: Connecticut Shoreline, Connecticut River Valley, and Litchfield Hills, each keeping its own frost calendar. Well-matched crops include apple, tomato, blueberry, and sugar maple, and the gap between "grows in the area" and "grows in your yard" is closed by soil, sun, and drainage.
Grounded inUSDA PHZM•NOAA Climate Normals•USDA NRCS SSURGO•GDD (PRISM 1991-2020 normals)•Chill hours (PRISM 1991-2020 normals)•USDA hardiness sub-region map•EPA FRS•USDA PLANTS•Growable Ground suitability scoring
Connecticut spans zones 6a-7b, but your yard sits in exactly one — and slope, tree cover, and low spots nudge it further. 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 Connecticut — soil, climate, flood, and parcel records. How we handle your address.
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Distinct growing regions within Connecticut — each has its own zones, soils, and signature crops.
Connecticut: USDA zones 6a-7b, 191–239 frost-free days depending on the county, 9 counties.
The middle half of this state’s counties. Tender transplants usually wait 2–3 weeks past the last hard freeze. The shortest-season figure is Connecticut's own county record — Northwest Hills Planning Region's measured 28°F normal, not a modeled floor.
Connecticut does not have one growing season. Across all 212 of its towns that carry their own 30-year record, the shortest measured season is Lakeville's at 175 days and the longest is Old Greenwich's at 250 — a 75-day spread inside one state.
Neither end is a lone reading — another 10 towns measure within 10 days of Lakeville and 11 sit within 10 days of Old Greenwich. These are real pockets, so the number to plant against is your own town's, not the state average.
NOAA Regional Climate Centers ACIS (1991–2020), 30-year daily minimum record
Zone 6a-7b is Connecticut's average, not your lot's — a low corner or a tree line moves it. Against Connecticut's 207-day season, see what your own ground reads.
One answer for Connecticut averages 9 counties whose growing seasons are 48 days apart — from 191 frost-free days in Northwest Hills Planning Region to 239 in Greater Bridgeport Planning Region. That is the same state, measured the same way, in the same years. Which end of it your county sits nearer decides what finishes before the first hard freeze.
The middle half of 9 counties runs 202–216 days, with a median of 207 days — a 48-day span end to end.
Measured across 9 counties, each carrying its own 28°F normal. NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze. A county with no record of its own is absent from the range rather than counted as zero — nothing here is interpolated to the state. Your own site sits somewhere inside this range; a parcel report resolves where.
The middle half of Connecticut runs 202–216 frost-free days, and 4 of its 9 counties sit outside that — 2 on the short side, 2 on the long. A statewide planting date describes the middle well and the ends poorly, which is worth knowing before you follow one.
Under 202 frost-free days
2 counties
The end of the state that sets the planting calendar — start seed indoors here and the season stretches to meet the crop.
202–216 frost-free days
5 counties
0 of 5 shown
The middle half of the state, and the part a single statewide date describes well.
Over 216 frost-free days
2 counties
Long enough for a second succession of a quick crop after the first comes out.
Each county is placed by its own 28°F frost-free normal (NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze), the same figure its own guide page publishes. Elevation, slope and cold-air drainage move a yard within its county as well — which is the part only your address resolves.
The soil types that dominate Connecticut — how each drains decides more about crop success than almost anything else. Tap any soil to learn what it is and how to work with it. Each photo is a representative profile of that soil type; the named series is where it was documented, which is often another state.
Drainage
Variable by the shovelful. Sandy till drains freely; dense, compacted till (hardpan) can perch water above it after snowmelt and heavy rain.
What thrives
Apples, stone fruits, brambles, and the whole northern vegetable garden do well on till — much of New England and the upper Midwest farms it. Deep-rooted perennials work through the stony structure happily.
Drainage
Fast. The sand fraction opens the soil up, so water moves through the root zone quickly and the surface rarely stays soggy. The trade is that nutrients ride out with the water.
What thrives
Root crops love it — carrots, potatoes, radishes, and onions size up cleanly in ground they can push through. Melons, sweet potatoes, asparagus, and most herbs appreciate the warmth and the drainage.
The fine fraction of a river’s load — smooth, fertile silt spread across valley floors and bottomlands by generations of floods.
Drainage
Moderate. It holds moisture generously through dry spells; in the lowest bottomland positions it can stay wet late into spring.
What thrives
Bottomland silt grows legendary sweet corn, squash, melons, and greens — the moisture-holding fertility suits big, thirsty crops.
Soil data: USDA NRCS SSURGO · Soil types explained
Plants well-suited to Connecticut's climate, soils, and growing season — each links to its full growing profile.
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Across Connecticut, cool-season planting typically opens about four weeks before the local last hard freeze — county medians put that freeze near Apr 7, with the middle half of counties between Mar 31 and Apr 11 (NOAA 1991–2020 climate normals). Tender transplants wait two to three weeks past it, and fall planting counts back from first freezes mostly between Oct 30 and Nov 3 — 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.
The plants Connecticut put its name on — cultural emblems, not growing recommendations.
Kalmia latifolia
Designated 1907. In our plant library — see its full growing profile.
Quercus alba
Designated 1947. In our plant library — see its full growing profile.
Plants the USDA PLANTS Database documents as native and present in Connecticut — a real per-state range, not just a zone match. Ordered by how closely each plant’s published hardiness range matches Connecticut’s zones 6a-7b, so this is a shortlist by climate fit, not a ranking of which plants matter most here. Presence is statewide, so a plant may still be uncommon in your specific county; your state’s Cooperative Extension or a native-plant society is the local authority.
US-native plants whose hardiness range overlaps Connecticut’s USDA zones 6a-7b but which USDA PLANTS doesn’t map to a single state range here. Zone overlap is a starting filter, not a range map.
What an experienced grower plans around here — each one has a move.
Rocky glacial soils require clearing and amendment
Skip the boulder harvest: a raised bed over cleared ground starts clean, and the rocks you do pull make fine bed borders.
Short growing season in northern hills
In the hills, choose fast-maturing varieties and add a cold frame — the season is short but very workable with an assist.
Deer pressure is high in suburban areas
Fencing works; repellents — rotated so deer never habituate — help between the fence posts.
For cultivar selection, pest pressure, and planting-time guidance specific to Connecticut, the UConn Extension is the authoritative local source.
Safe to Grow Here?What the federal record shows across Connecticut — and how to grow with it.
We checked the federal record across Connecticut — 19,222 documented sites across 8 of the 9 source types we track.
The most significant on record: 279 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
Connecticut carries one of the heavier federal records we track — and that's not a verdict on your yard. Proximity to a documented site is information, not a diagnosis: nothing here says any particular parcel is affected. It does earn one concrete step — before food beds go in the ground, a professional soil test tells you exactly what you're working with, and raised beds with clean imported soil grow well almost anywhere in the meantime.
Severity Distribution
across Connecticut
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around Connecticut, Superfund runs higher than the national average — 279 sites across Connecticut. 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).
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
Everything above resolves to Connecticut as a whole — a state whose own counties record seasons 48 days apart, and hardiness across zones 6a-7b. Your parcel sits at one point in that range, not in the middle of it. 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 state 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 statewide average.
State averages sketch the shape. Your soil, sun exposure, drainage, and microclimate decide what actually takes. Pull a site-specific report for your exact parcel.
Enter your address. We read your soil, sun, drainage, and frost dates, then score 1,086 plants against the real conditions on your land.
Three things about your lot that Connecticut averages can't show:
We read public map data around Connecticut — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Connecticut average
The datasets: hardiness from the USDA ARS Plant Hardiness Zone Map 2023, read per county and aggregated to the state band; the growing season from NOAA Regional Climate Centers ACIS 1991–2020 28°F normals, read at each county’s own record; rainfall from NOAA Climate Normals; soils from USDA NRCS SSURGO; boundaries from US Census TIGER/Line 2025; the contamination record from the federal sources named in that beat above. Where a county carries no record of its own, it is absent from the figure rather than filled in.
Connecticut spans USDA hardiness zones 6a-7b — which is to say winter's coldest night runs from about −10°F to 10°F depending where in Connecticut you are, averaged over 1991–2020 (USDA PHZM 2023).
Too late for some crops, right on time for others — a growing season is a sequence, not a deadline. Across Connecticut, cool-season planting typically opens about four weeks before the local last hard freeze — county medians put that freeze near Apr 7, with the middle half of counties between Mar 31 and Apr 11 (NOAA 1991–2020 climate normals). Tender transplants wait two to three weeks past it, and fall planting counts back from first freezes mostly between Oct 30 and Nov 3 — 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.
Across Connecticut, the middle half of counties see their last hard freeze (28°F) between about Mar 31 and Apr 11, with a county median near Apr 7 (NOAA 1991–2020 climate normals). 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 28.
Measured between 28°F hard freezes, growing seasons across Connecticut's counties mostly run about 202 to 216 days, with a county median near 207 (NOAA 1991–2020 climate normals). Tender crops get a somewhat shorter practical window, since lighter frosts reach a few weeks past the hard-freeze dates on both ends.
Connecticut's zones 6a-7b support a wide range — strong performers include Apple, Tomato, Blueberry, Sugar Maple, and Garlic. What actually takes on any one site comes down to its soil, sun, and drainage, and we score each plant against the real conditions at your address.
Officially, Connecticut spans USDA zones 6a-7b (USDA PHZM 2023) — but a zone is a 30-year average of winter's coldest night across an area, and it can't see any one yard. A south-facing slope, a tree line, or a low frost pocket can shift a single site by half a zone either way, which is why neighboring gardeners often quote different numbers. We read the conditions at your exact address — soil, sun, slope, and frost — and score 1,086 plants against what's actually there.
The federal record across Connecticut runs heavier than most — 19,222 documented sites, mostly Underground Storage Tanks entries (9,356) — so test the soil before planting food in the ground, and raised beds with clean imported soil grow well in the meantime. Even here, proximity to a documented site is information, not a diagnosis of any one yard; the contamination map shows exactly what's recorded and where.
Start with three facts. Connecticut spans USDA zones 6a-7b, which sets what survives winter; last hard freezes range from about Mar 31 to Apr 11 across its counties (NOAA 1991–2020 climate normals); and 19,222 documented sites sit on the federal record here, so a soil test before food beds is the smart first step. From there, matching plants to your actual soil and sun is the fun part.
Everything above is measured at Connecticut's scale — its 6a-7b band and its 207-day season. Your yard writes its own version of Connecticut's numbers: we read soil, sun, drainage and frost at your exact address. Try it for 14 days — no card required.
6 of the readings below were taken at Connecticut's own scale — the full zone 6a-7b span inside its borders, the 3 soil types that dominate its ground and 19,222 documented sites on its federal record; anything it cannot resolve at this scale is named below.
Measured here
What this page can’t tell you
Explore growing conditions by county — each has its own zone range and land area.
Explore growing conditions by city or town in Connecticut.
Connecticut shares its dominant growing region with these states — a useful comparison if you're weighing where a crop will behave the same way.
