Connecticut spans USDA hardiness zones 5b-7a, with a growing season of about 170 frost-free days — a working season long enough for the classics, short enough that timing around frost stays part of the craft.
In practice the season is written by 44-52 inches of annual rainfall, a median of roughly 2,900 growing-degree days (base 50°F), and about 1,500 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. 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 2023•NOAA Climate Normals•USDA NRCS SSURGO•GDD aggregate (Cornell CALS)•Chill-hour aggregate (MSU Extension)•EPA FRS•USDA PLANTS•Growable Ground suitability scoring
Connecticut spans zones 5b-7a, but your yard sits in exactly one — and slope, tree cover, and low spots nudge it further. Enter your address and we'll score 1,112 plants against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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USDA Zones
5b-7a
USDA PHZM 2023
Last Frost
Apr 15 - May 15
NOAA 30-yr Normals
First Frost
Sep 25 - Oct 25
NOAA 30-yr Normals
Annual Rainfall
44-52 inches
NOAA Climate Normals
Zone maps are averages across Connecticut. Your yard's slope, trees, and frost pockets shift what actually grows — see your land's exact reading.
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.
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.
See the alluvial profile — river silt is its fine, fertile bottomland fraction.
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 Mar 31, with the middle half of counties between Mar 30 and Apr 4 (NOAA 1991–2020 climate normals). Tender transplants wait two to three weeks past it, and fall planting counts back from first freezes mostly between Nov 19 and Nov 24 — 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. 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 5b-7a 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 nearby. 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.
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 1,112 plants against the real conditions on your land.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources analyzed in seconds
Connecticut spans USDA hardiness zones 5b-7a, per the USDA Plant Hardiness Zone Map 2023. Zones reflect average annual extreme minimum temperatures from 1991–2020 weather data.
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 Mar 31, with the middle half of counties between Mar 30 and Apr 4 (NOAA 1991–2020 climate normals). Tender transplants wait two to three weeks past it, and fall planting counts back from first freezes mostly between Nov 19 and Nov 24 — 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 30 and Apr 4, with a county median near Mar 31 (NOAA 1991–2020 climate normals). That marks the hard freeze, not the last light frost — light frosts can still bite for a few more weeks, so tender transplants usually wait another 2–3 weeks.
Measured between 28°F hard freezes, growing seasons across Connecticut's counties mostly run about 229 to 239 days, with a county median near 237 (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 5b-7a 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 5b-7a (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 1,112 plants against what's actually there.
The federal record across Connecticut runs heavier than most — 19,222 documented sites — 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 5b-7a, which sets what survives winter; last hard freezes range from about Mar 30 to Apr 4 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 on this page is a Connecticut average. Your yard writes its own version — we read soil, sun, drainage, and frost at your exact address. Try it for 14 days — no card required.
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.
