Unlikely — Zone Mismatch
cassava (zones 8-12) does not overlap with Connecticut's zone range (6a-7b). Growing outdoors is unlikely without significant protection.
One zone short — what would close it
Cassava is hardy to zone 8, and the warmest ground in Connecticut is zone 7 — 1 zone short. Planted in open ground it will not survive a Connecticut winter. To grow it here, grow cassava in a hoop house or unheated greenhouse — its modeled 1.5-zone lift covers this gap.
A hoop house or unheated greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 8-12 (plant) against 5-7 (Connecticut). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['hoop_house'] (+1.5 zones) via api/fast_sections.py Unlock Engine v2.
Cassava in Connecticut — the short answer
Cassava in Connecticut: hardy in zones 8–12, full sun, against a state median of ~207 frost-free days.
- Plant zones
- 8-12
- Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
- Connecticut zones
- 6a-7b
- USDA PHZM 2023
- Frost window
- Mar 31 - Apr 11 – Oct 30 - Nov 3
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 191 days
- NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
- Days to maturity
- 270 days
- Growable Ground Plant Database
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.
Your yard isn't the whole zone.
Connecticut spans zones 6a-7b, but your yard sits in exactly one — and slope, tree cover, and cold-air pockets nudge it further. Enter your address and we'll score cassava against your parcel's actual hardiness, soil, and sun.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Connecticut is not one climate
Connecticut’s winter-low ladder runs across 9 counties, from zone 6 in Northwest Hills County to zone 7 in South Central Connecticut County. That is 10°F between the two counties’ average coldest night — the difference between cassava overwintering in the ground and coming under cover.
The middle half of 9 counties runs 6.5–6.5 zones, with a median of 6.5 zones — a 1-zone span end to end.
Measured across 9 Connecticut counties. USDA PHZM 2023, per county. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.
Where Cassava Stands in Connecticut
Cassava is rated for zones 8–12 — a cold floor USDA puts at 10 to 20°F. No Connecticut county sits inside it, so in open ground this is a grown-under-cover plant here rather than a bed plant — which is a statement about Connecticut winters, not about cassava.
Below the zone 8 floor
9 counties
- Northwest Hills County · zone 6a
- Capitol County · zone 6b
- Lower Connecticut River Valley County · zone 6b
3 of 9 shown
Winter cold is the limit here — the same plant works in a container that comes under cover.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. A zone is a 10°F band of average annual extreme minimum temperature, so the floor above is the band the plant's rating denotes, not a single measured kill point. Slope, shelter and cold-air drainage routinely move a site half a zone either way from its county figure — which is the part only your address resolves.
Zone Comparison
Cassava Needs
- USDA Zones: 8-12
- Frost-Free Days: 180+
- Sun: Full Sun
- Mature size: 8 ft tall
- Picking window: ~30 days of harvest
- Drought tolerance: Low
Connecticut Has
- USDA Zones: 6a-7b
- Last Hard Freeze (28°F): Mar 31 - Apr 11
- First Hard Freeze (28°F): Oct 30 - Nov 3
- Annual Rainfall: 44-52 inches
- Common Soils: Glacial till, Sandy loam, River valley silt
Plant Zone Range (zones 8-12)
Preferred Soil pH
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Cassava in Connecticut
The frost window
Across Connecticut, the last spring hard freeze (28°F) clears between Mar 31 and Apr 11, and the first fall hard freeze lands between Oct 30 and Nov 3 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 202-day window you can count on — up to 217 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.
Winter standing
Cassava overwinters from USDA zone 10 and warmer (NC State Extension Gardener Plant Toolbox; Missouri Botanical Garden Plant Finder), and Connecticut runs as cold as zone 6, so it does not survive winter in the ground here. It is a woody plant rather than a crop you resow each spring, so neither a fall establishment date nor a harvest countdown describes it in Connecticut — which is why this page gives neither. What it needs here is a way through winter, not a planting date.
Timing tuned to sub-state frost dates — Northwest Hills County, not the statewide average.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.
Growing Season Fit
The zone check says cassava does not survive a Connecticut winter in the ground. The season figures below measure a different question — whether it could finish a season here at all — and they only bear on Connecticut under protection.
Frost-free days
Cassava wants 180+ frost-free days; a typical Connecticut site sees ~207 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves a workable window — start indoors to bank time.
Growing degree days
Cassava needs ~4000 GDD (base 50°F) to ripen. The state median runs ~2664 GDD (from PRISM 1991-2020 climate normals), so Connecticut's typical season runs short on heat — pick a south-facing site and consider season extension.
GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS, 1991-2020. Each is the state median across its counties (P25/P75 span the within-state spread). Hardiness-zone range is USDA PHZM 2023.
Soil + Drainage Fit
Cassava tolerates a wide pH range (pH 4-9) — 5 units, acid ground through alkaline — so soil acidity is rarely what limits it in Connecticut. A soil test is still worth having, but for what else it tells you about this site, not to clear this plant. It will grow across that whole span, but it does best between pH 5.5 and 8 — worth knowing before you decide whether a Connecticut soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Connecticut site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
Whether cassava is safe to eat from Connecticut soil is a block-by-block question, not a town-wide one — 19,222 documented contamination sites mean levels spike on some parcels and not the one next door. Cassava roots to about 19 inches, so it is the top 19 inches under your address that decide what it takes up, so only a test on your address settles it.
Check your parcel → Source: USDA NRCS SSURGO + EPA/state contamination databases.
Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Connecticut soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Before you plant cassava for food
Anything you grow to eat takes up what is in the ground it grows in, so what is on record near you is worth knowing before cassava goes in. What follows is Connecticut’s documented federal record at state scale — a screening signal, not a soil test, and not a statement about any one lot.
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.
Sources Checked
across Connecticut
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.
What Else to Consider for Cassava in Connecticut
Zone compatibility tells you about winter cold survival — but Connecticut growers also need to think about:
Rocky glacial soils require clearing and amendment
Short growing season in northern hills
Deer pressure is high in suburban areas
Growing cassava here specifically
Cassava grows its edible root in the soil itself, so on any of Connecticut's 19,222 documented contamination sites it can carry up lead you'd then eat.
Keep cassava in raised beds of screened clean soil and confirm your parcel's lead level before the first crop. How to handle it →
What to actually do about these — and the constraints that apply to every Connecticut grower, not just cassava — is covered on the Connecticut growing guide.
Timing shifts within Connecticut
Connecticut isn't one climate. In Northwest Hills County, the last hard freeze (28°F) holds until about Apr 19 — roughly 12 days later than the recorded state median — so plant cassava to your county's window, not the statewide date.
Cassava needs about 180 days of frost-free season to complete its cycle. Even Northwest Hills County — Connecticut’s shortest season at 191 frost-free days — clears that by 11 days, so season length isn’t the constraint anywhere in Connecticut. What varies is your own parcel.
County last-freeze dates and frost-free day counts: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). Cassava's 180-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Pollinator + Wildlife Value
Cassava draws honeybees (low value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, cassava can only work that bloom inside Connecticut's frost window — roughly 207 days, opening after the last 28°F freeze (Mar 31 - Apr 11) and closing at the first (Oct 30 - Nov 3), per NOAA Regional Climate Centers ACIS, 1991-2020.
Good to Know Before You Plant Cassava
Cassava is listed as toxic to dogs, cats (all) at a severe level (Cornell). Most listed plants only cause brief upset — a raised bed or a fenced corner usually keeps curious pets clear. Worth knowing for placement: cassava is woody and hardy only from zone 10, against a Connecticut low of zone 6, so it is overwintered under cover here rather than left standing outside — which is where it will be in reach.
Connecticut Cooperative Extension
For Connecticut-specific cultivar recommendations, planting calendars, and pest pressure for cassava, the canonical source is UConn Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Cassava native to Connecticut?
No — the USDA PLANTS Database lists Cassava as introduced rather than native in the Lower 48, so it is not part of Connecticut's native flora. It grows here as a garden plant; pairing it with a few Connecticut natives keeps local pollinators fed too.
Looking for plants that belong here? The Connecticut growing guide lists USDA-documented natives for the state.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
Common Questions About Growing Cassava in Connecticut
When can I plant Cassava in Connecticut?
Connecticut's last spring hard freeze (28°F) clears between Mar 31 and Apr 11, and the first fall hard freeze lands between Oct 30 and Nov 3 (NOAA Regional Climate Centers ACIS, 1991-2020). Cassava overwinters only from USDA zone 10 and warmer, and Connecticut runs as cold as zone 6, so it does not survive winter in the ground here — the question for Connecticut growers is how to carry it through winter under cover, not which week to plant it.
What hardiness zone is Cassava grown in across Connecticut?
Connecticut spans USDA hardiness zones 6a-7b (USDA ARS PHZM 2023). Cassava carries a range of zones 8-12, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Connecticut site have?
A typical Connecticut site sees ~207 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Cassava needs 180+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date. In cooler counties like Northwest Hills, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Cassava native to Connecticut?
No — the USDA PLANTS Database lists Cassava as introduced rather than native in the Lower 48, so it is not part of Connecticut's native flora. It grows here as a garden plant; pairing it with a few Connecticut natives keeps local pollinators fed too.
How should I amend the soil for Cassava in Connecticut?
Cassava tolerates pH 4-9 and well (dry spells) drainage (FAO ECOCROP). That is a 5-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Connecticut site — amend for drainage and organic matter first.
Will Cassava actually grow on my specific land in Connecticut?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores cassava against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.
Check your specific parcel in Connecticut
State-level data is a sketch. Your Growable Ground report scores cassava against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Connecticut cassava 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 cassava average
Explore More
Growing guides for cassava
Explore Connecticut county by county
Connecticut carries 9 counties with their own USDA zone — a sample of the growing pages for cassava there:
Where else cassava grows
Cassava's zone band crosses state lines — these are the states closest to Connecticut in winter climate where it also has a page, plus the far ends of its range. Each one re-answers the question with that state's own record.
More to grow in Connecticut
Connecticut has a growing page for 893 plants — a rotating sample of the rest of the shelf.
Analysis by the Growable Ground research team, grounded in USDA PLANTS, USDA NRCS SSURGO, NOAA Climate Normals (1991-2020), and named Cooperative Extension sources. How we know →
Cite this dataset
Kirchick, M. (2026). Growable Ground Plant Database [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21435643
Licensed CC BY-NC 4.0. DOI 10.5281/zenodo.21435643
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