Ezina · A field manual for plant care · United StatesVol. I · Ed. 2027 · Proof copy

Connecticut invasive plants

Connecticut (CT) regulates 60 invasive plants under Conn. Gen. Stat. 22a-381d (as amended by P.A. 24-11). Connecticut's list is a trade restriction, which governs what may be sold, propagated, or moved within the state — in plain terms, which plants are illegal to sell here.

Connecticut invasive species list

Connecticut restricts 60 plants, including Canada Thistle, Leafy Spurge and Waterthyme. Plants marked Prohibited may not be sold, propagated, or moved within Connecticut. 53 of the 60 are also flagged invasive by GRIIS, which is an ecological finding rather than a ruling by Connecticut. Checked against Conn. Gen. Stat. 22a-381d (as amended by P.A. 24-11) on July 20, 2026.

Amur Honeysuckle – Lonicera maackii Not recorded hereInvasive

Amur Honeysuckle (Lonicera maackii)
Photo by Herman, D.E., et al / Public domain / ND State Soil Conservation Committee / via USDA PLANTS

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Amur Honeysuckle as a prohibited invasive plant.

Asiatic Tearthumb – Polygonum perfoliatum Not recorded hereInvasive

Asiatic Tearthumb (Polygonum perfoliatum)
Photo by Dalgial / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Asiatic Tearthumb as a prohibited invasive plant.

Autumn Olive – Elaeagnus umbellata Not recorded hereInvasive

Autumn Olive (Elaeagnus umbellata)
Photo by KENPEI / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Autumn Olive as a prohibited invasive plant.

Bolleana Poplar – Populus alba 'Pyramidalis' Not recorded hereInvasive

Bolleana Poplar (Populus alba 'Pyramidalis')
Photo by Herman, D.E., et al / Public domain / ND State Soil Conservation Committee / via USDA PLANTS

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Bolleana Poplar as a prohibited invasive plant.

Brazilian Waterweed – Egeria densa Not recorded hereInvasive

Brazilian Waterweed (Egeria densa)
Photo by Lara Gudmundsdottir / CC BY-SA 4.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Brazilian Waterweed as a prohibited invasive plant.

Broadleaved Pepperweed – Lepidium latifolium Not recorded hereInvasive

Broadleaved Pepperweed (Lepidium latifolium)
Photo by Sam Thomas / CC BY 2.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Broadleaved Pepperweed as a prohibited invasive plant.

Burningbush – Bassia scoparia Not recorded hereInvasive

Burningbush (Bassia scoparia)
Photo by Rameshng / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Burningbush as a prohibited invasive plant.

Canada Bluegrass – Poa compressa Not recorded hereInvasive

Canada Bluegrass (Poa compressa)
Photo by James K. Lindsey / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Canada Bluegrass as a prohibited invasive plant.

Canada Thistle – Cirsium arvense Not recorded hereInvasive

Canada Thistle (Cirsium arvense)
Photo by Richard Bartz, Munich aka Makro Freak / CC BY-SA 2.5 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Canada Thistle as a prohibited invasive plant.

Carolina Fanwort – Cabomba caroliniana Not recorded hereProhibited

Carolina Fanwort (Cabomba caroliniana)
Photo by Leslie J. Mehrhoff, University of Connecticut, Bugwood.org / CC BY 3.0 / Wikimedia Commons

Recorded in no Connecticut county. Connecticut lists Carolina Fanwort as a prohibited invasive plant.

Cheatgrass – Bromus tectorum Not recorded hereInvasive

Cheatgrass (Bromus tectorum)
Photo by Robert Soreng / CC0 / Smithsonian Open Access / via USDA PLANTS

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Cheatgrass as a prohibited invasive plant.

Climbing Nightshade – Solanum dulcamara Not recorded hereInvasive

Climbing Nightshade (Solanum dulcamara)
Photo by Sheri Hagwood / Public domain / via USDA PLANTS

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Climbing Nightshade as a prohibited invasive plant.

Coltsfoot – Tussilago farfara Not recorded hereInvasive

Coltsfoot (Tussilago farfara)
Photo by Howard, R.A / Public domain / Smithsonian Institution, Richard A. Howard Photograph Collection / via USDA PLANTS

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Coltsfoot as a prohibited invasive plant.

Common Barberry – Berberis vulgaris Not recorded hereInvasive

Common Barberry (Berberis vulgaris)
Photo by Unknown photographer / Public domain / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Common Barberry as a prohibited invasive plant.

Common Buckthorn – Rhamnus cathartica Not recorded hereInvasive

Common Buckthorn (Rhamnus cathartica)
Photo by Köhler, F. E. (Franz Eugen) / Public domain / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Common Buckthorn as a prohibited invasive plant.

Common Reed – Phragmites australis Not recorded hereProhibited

Common Reed (Phragmites australis)
Photo by Howard, R.A / Public domain / Smithsonian Institution, Richard A. Howard Photograph Collection / via USDA PLANTS

Recorded in no Connecticut county. Connecticut lists Common Reed as a prohibited invasive plant.

Common Sheep Sorrel – Rumex acetosella Not recorded hereInvasive

Common Sheep Sorrel (Rumex acetosella)
Photo by Robert H. Mohlenbrock. USDA NRCS / Public domain / USDA NRCS Wetland Science Institute (WSI) / via USDA PLANTS

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Common Sheep Sorrel as a prohibited invasive plant.

Crested Latesummer Mint – Elsholtzia ciliata Not recorded hereInvasive

Crested Latesummer Mint (Elsholtzia ciliata)
Photo by Leslie J. Mehrhoff, University of Connecticut, Bugwood.org / CC BY 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Crested Latesummer Mint as a prohibited invasive plant.

Cup Plant – Silphium perfoliatum Not recorded hereProhibited

Cup Plant (Silphium perfoliatum)
Photo by Douglas Ladd. USDA SCS / Public domain / USDA NRCS Wetland Science Institute (WSI) / via USDA PLANTS

Recorded in no Connecticut county. Connecticut lists Cup Plant as a prohibited invasive plant.

Curly Pondweed – Potamogeton crispus Not recorded hereInvasive

Curly Pondweed (Potamogeton crispus)
Photo by Unknown photographer / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Curly Pondweed as a prohibited invasive plant.

Cypress Spurge – Euphorbia cyparissias Not recorded hereInvasive

Cypress Spurge (Euphorbia cyparissias)
Photo by Didier Descouens / CC BY-SA 4.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Cypress Spurge as a prohibited invasive plant.

Dames Rocket – Hesperis matronalis Not recorded hereInvasive

Dames Rocket (Hesperis matronalis)
Photo by Howard, R.A / Public domain / Smithsonian Institution, Richard A. Howard Photograph Collection / via USDA PLANTS

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Dames Rocket as a prohibited invasive plant.

Empress Tree – Paulownia tomentosa Not recorded hereInvasive

Empress Tree (Paulownia tomentosa)
Photo by Jean-Pol GRANDMONT / CC BY 2.5 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Empress Tree as a prohibited invasive plant.

Eurasian Watermilfoil – Myriophyllum spicatum Not recorded hereInvasive

Eurasian Watermilfoil (Myriophyllum spicatum)
CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Eurasian Watermilfoil as a prohibited invasive plant.

European Swallow-Wort – Cynanchum rossicum Not recorded hereInvasive

European Swallow-Wort (Cynanchum rossicum)
Photo by Epibase / CC BY 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists European Swallow-Wort as a prohibited invasive plant.

False Indigobush – Amorpha fruticosa Not recorded hereProhibited

False Indigobush (Amorpha fruticosa)
Photo by Herman, D.E., et al / Public domain / ND State Soil Conservation Committee / via USDA PLANTS

Recorded in no Connecticut county. Connecticut lists False Indigobush as a prohibited invasive plant.

Fig Buttercup – Ranunculus ficaria Not recorded hereInvasive

Fig Buttercup (Ranunculus ficaria)
Photo by Michal Osmenda from Brussels, Belgium / CC BY-SA 2.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Fig Buttercup as a prohibited invasive plant.

Garden Valerian – Valeriana officinalis Not recorded hereInvasive

Garden Valerian (Valeriana officinalis)
Photo by Ivar Leidus / CC BY-SA 4.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Garden Valerian as a prohibited invasive plant.

Garlic Mustard – Alliaria petiolata Not recorded hereInvasive

Garlic Mustard (Alliaria petiolata)
Photo by O. Pichard / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Garlic Mustard as a prohibited invasive plant.

Giant Hogweed – Heracleum mantegazzianum Not recorded hereInvasive

Giant Hogweed (Heracleum mantegazzianum)
Photo by Lucas Kendall / CC BY-SA 4.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Giant Hogweed as a prohibited invasive plant.

Giant Knotweed – Polygonum sachalinense Not recorded hereInvasive

Giant Knotweed (Polygonum sachalinense)
Photo by Velocicaptor at en.wikipedia / Public domain / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Giant Knotweed as a prohibited invasive plant.

Ground Ivy – Glechoma hederacea Not recorded hereInvasive

Ground Ivy (Glechoma hederacea)
Photo by Howard, R.A / Public domain / Smithsonian Institution, Richard A. Howard Photograph Collection / via USDA PLANTS

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Ground Ivy as a prohibited invasive plant.

Japanese Hop – Humulus japonicus Not recorded hereInvasive

Japanese Hop (Humulus japonicus)
Photo by Mark A. Garland / Public domain / via USDA PLANTS

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Japanese Hop as a prohibited invasive plant.

Japanese Knotweed – Polygonum cuspidatum Not recorded hereProhibited

Japanese Knotweed (Polygonum cuspidatum)
Photo by W.carter / CC0 / Wikimedia Commons

Recorded in no Connecticut county. Connecticut lists Japanese Knotweed as a prohibited invasive plant.

Japanese Sedge – Carex kobomugi Not recorded hereInvasive

Japanese Sedge (Carex kobomugi)
Photo by self / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Japanese Sedge as a prohibited invasive plant.

Jimsonweed – Datura stramonium Not recorded hereInvasive

Jimsonweed (Datura stramonium)
Photo by Patrick J. Alexander / Public domain / via USDA PLANTS

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Jimsonweed as a prohibited invasive plant.

Kudzu – Pueraria montana Not recorded hereInvasive

Kudzu (Pueraria montana)
Photo by Schurdl / CC BY-SA 4.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Kudzu as a prohibited invasive plant.

Leafy Spurge – Euphorbia esula Not recorded hereInvasive

Leafy Spurge (Euphorbia esula)
Photo by Ivar Leidus / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Leafy Spurge as a prohibited invasive plant.

Louise's Swallow-Wort – Cynanchum louiseae Not recorded hereInvasive

Louise's Swallow-Wort (Cynanchum louiseae)
Photo by Part of a work by Britton, N.L., and A. Brown / Public domain / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Louise's Swallow-Wort as a prohibited invasive plant.

Morrow's Honeysuckle – Lonicera morrowii Not recorded hereInvasive

Morrow's Honeysuckle (Lonicera morrowii)
Photo by Easai at English Wikipedia / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Morrow's Honeysuckle as a prohibited invasive plant.

Multiflora Rose – Rosa multiflora Not recorded hereInvasive

Multiflora Rose (Rosa multiflora)
Photo by Famartin / CC BY-SA 4.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Multiflora Rose as a prohibited invasive plant.

Narrowleaf Bittercress – Cardamine impatiens Not recorded hereInvasive

Narrowleaf Bittercress (Cardamine impatiens)
CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Narrowleaf Bittercress as a prohibited invasive plant.

Nepalese Browntop – Microstegium vimineum Not recorded hereInvasive

Nepalese Browntop (Microstegium vimineum)
Photo by James H. Miller & Ted Bodner, Southern Weed Science Society, Bugwood.org / CC BY 3.0 us / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Nepalese Browntop as a prohibited invasive plant.

Oriental Bittersweet – Celastrus orbiculatus Not recorded hereInvasive

Oriental Bittersweet (Celastrus orbiculatus)
Photo by Unknown photographer / Public domain / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Oriental Bittersweet as a prohibited invasive plant.

Ornamental Jewelweed – Impatiens glandulifera Not recorded hereInvasive

Ornamental Jewelweed (Impatiens glandulifera)
Photo by Howard, R.A / Public domain / Smithsonian Institution, Richard A. Howard Photograph Collection / via USDA PLANTS

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Ornamental Jewelweed as a prohibited invasive plant.

Ragged Robin – Lychnis flos-cuculi Not recorded hereInvasive

Ragged Robin (Lychnis flos-cuculi)
Photo by Ivar Leidus / CC BY-SA 4.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Ragged Robin as a prohibited invasive plant.

Russian Olive – Elaeagnus angustifolia Not recorded hereInvasive

Russian Olive (Elaeagnus angustifolia)
Photo by Herman, D.E., et al / Public domain / ND State Soil Conservation Committee / via USDA PLANTS

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Russian Olive as a prohibited invasive plant.

Scotch Cottonthistle – Onopordum acanthium Not recorded hereInvasive

Scotch Cottonthistle (Onopordum acanthium)
Photo by penarc / Public domain / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Scotch Cottonthistle as a prohibited invasive plant.

Showy Fly Honeysuckle – Lonicera x bella Not recorded hereInvasive

Showy Fly Honeysuckle (Lonicera x bella)
Photo by Leslie J. Mehrhoff, University of Connecticut, Bugwood.org / CC BY 3.0 us / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Showy Fly Honeysuckle as a prohibited invasive plant.

Slender Snakecotton – Froelichia gracilis Not recorded hereProhibited

Slender Snakecotton (Froelichia gracilis)
Photo by Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner's Sons, New York. Vol. 2: 8. Courtesy of Kentucky Native Plant Society. Scanned by Omnitek Inc. / Public domain / Wikimedia Commons

Recorded in no Connecticut county. Connecticut lists Slender Snakecotton as a prohibited invasive plant.

Small Carpetgrass – Arthraxon hispidus Not recorded hereInvasive

Small Carpetgrass (Arthraxon hispidus)
Photo by No machine-readable author provided. Keisotyo assumed (based on copyright claims). / CC BY 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Small Carpetgrass as a prohibited invasive plant.

Spotted Knapweed – Centaurea stoebe subsp. micranthos Not recorded hereInvasive

Spotted Knapweed (Centaurea stoebe subsp. micranthos)
Photo by Patrick J. Alexander / Public domain / via USDA PLANTS

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Spotted Knapweed as a prohibited invasive plant.

Stinking Willie – Senecio jacobaea Not recorded hereInvasive

Stinking Willie (Senecio jacobaea)
Photo by Carl Axel Magnus Lindman / Public domain / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Stinking Willie as a prohibited invasive plant.

Sycamore Maple – Acer pseudoplatanus Not recorded hereInvasive

Sycamore Maple (Acer pseudoplatanus)
Photo by Willow / CC BY 2.5 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Sycamore Maple as a prohibited invasive plant.

Tree of Heaven – Ailanthus altissima Not recorded hereInvasive

Tree of Heaven (Ailanthus altissima)
Photo by USDA Forest Service / Public domain / USDA Forest Service / via USDA PLANTS

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Tree of Heaven as a prohibited invasive plant.

Twoleaf Watermilfoil – Myriophyllum heterophyllum Not recorded hereProhibited

Twoleaf Watermilfoil (Myriophyllum heterophyllum)
Photo by Robert H. Mohlenbrock. USDA NRCS / Public domain / USDA NRCS Wetland Science Institute (WSI) / via USDA PLANTS

Recorded in no Connecticut county. Connecticut lists Twoleaf Watermilfoil as a prohibited invasive plant.

Variegated Water Grass – Glyceria maxima 'Variegata' Not recorded hereInvasive

Variegated Water Grass (Glyceria maxima 'Variegata')
Photo by Rasbak / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Variegated Water Grass as a prohibited invasive plant.

Water Chestnut – Trapa natans Not recorded hereInvasive

Water Chestnut (Trapa natans)
Photo by Krzysztof Ziarnek, Kenraiz / CC BY-SA 4.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Water Chestnut as a prohibited invasive plant.

Waterthyme – Hydrilla verticillata Not recorded hereInvasive

Waterthyme (Hydrilla verticillata)
Public domain / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Waterthyme as a prohibited invasive plant.

Wine Raspberry – Rubus phoenicolasius Not recorded hereInvasive

Wine Raspberry (Rubus phoenicolasius)
Photo by Rasbak / CC BY-SA 3.0 / Wikimedia Commons

Invasive in the US, and recorded in no Connecticut county. Connecticut lists Wine Raspberry as a prohibited invasive plant.

5 of these plants are native to part of the United States, marked US native above. Nativity is regional. Black locust is native to the Appalachians and regulated in New England; Palmer amaranth is native to the Southwest and listed as an agricultural weed in the Corn Belt. A listing tells you what Connecticut regulates, not where a plant belongs. The county checker answers the second question.

Want to check a plant by photo or county?

Use our “Is it native” tool for free.

Compiled from the rule itself, retrieved July 20, 2026. Law changes; if you spot a listing we have wrong or stale, tell us at support@getezina.com.

The same list as a table
Plant Scientific name Status Plant instead
Amur Honeysuckle Lonicera maackii ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Asiatic Tearthumb Polygonum perfoliatum ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Autumn Olive Elaeagnus umbellata ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Bolleana Poplar Populus alba 'Pyramidalis' ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Brazilian Waterweed Egeria densa ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Broadleaved Pepperweed Lepidium latifolium ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Burningbush Bassia scoparia ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Canada Bluegrass Poa compressa ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Canada Thistle Cirsium arvense ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Carolina Fanwort US native Cabomba caroliniana ProhibitedConnecticut says “prohibited invasive plant” —
Cheatgrass Bromus tectorum ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Climbing Nightshade Solanum dulcamara ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Coltsfoot Tussilago farfara ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Common Barberry Berberis vulgaris ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Common Buckthorn Rhamnus cathartica ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Common Reed Phragmites australis ProhibitedConnecticut says “prohibited invasive plant” —
Common Sheep Sorrel Rumex acetosella ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Crested Latesummer Mint Elsholtzia ciliata ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Cup Plant US native Silphium perfoliatum ProhibitedConnecticut says “prohibited invasive plant” —
Curly Pondweed Potamogeton crispus ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Cypress Spurge Euphorbia cyparissias ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Dames Rocket Hesperis matronalis ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Empress Tree Paulownia tomentosa ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Eurasian Watermilfoil Myriophyllum spicatum ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
European Swallow-Wort Cynanchum rossicum ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
False Indigobush US native Amorpha fruticosa ProhibitedConnecticut says “prohibited invasive plant” —
Fig Buttercup Ranunculus ficaria ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Garden Valerian Valeriana officinalis ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Garlic Mustard Alliaria petiolata ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Giant Hogweed Heracleum mantegazzianum ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Giant Knotweed Polygonum sachalinense ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Ground Ivy Glechoma hederacea ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Japanese Hop Humulus japonicus ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Japanese Knotweed Polygonum cuspidatum ProhibitedConnecticut says “prohibited invasive plant” —
Japanese Sedge Carex kobomugi ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Jimsonweed Datura stramonium ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Kudzu Pueraria montana ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Leafy Spurge Euphorbia esula ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Louise's Swallow-Wort Cynanchum louiseae ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Morrow's Honeysuckle Lonicera morrowii ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Multiflora Rose Rosa multiflora ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Narrowleaf Bittercress Cardamine impatiens ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Nepalese Browntop Microstegium vimineum ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Oriental Bittersweet Celastrus orbiculatus ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Ornamental Jewelweed Impatiens glandulifera ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Ragged Robin Lychnis flos-cuculi ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Russian Olive Elaeagnus angustifolia ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Scotch Cottonthistle Onopordum acanthium ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Showy Fly Honeysuckle Lonicera x bella ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Slender Snakecotton US native Froelichia gracilis ProhibitedConnecticut says “prohibited invasive plant” —
Small Carpetgrass Arthraxon hispidus ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Spotted Knapweed Centaurea stoebe subsp. micranthos ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Stinking Willie Senecio jacobaea ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Sycamore Maple Acer pseudoplatanus ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Tree of Heaven Ailanthus altissima ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Twoleaf Watermilfoil US native Myriophyllum heterophyllum ProhibitedConnecticut says “prohibited invasive plant” —
Variegated Water Grass Glyceria maxima 'Variegata' ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Water Chestnut Trapa natans ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Waterthyme Hydrilla verticillata ProhibitedInvasiveConnecticut says “prohibited invasive plant” —
Wine Raspberry Rubus phoenicolasius ProhibitedInvasiveConnecticut says “prohibited invasive plant” —

What the tags mean

Two separate findings. Invasive is ecological. The other three are legal statuses Connecticut sets in statute, and which one applies turns on what the rule obliges, and of whom.

Invasive
An ecological finding, and a different question from the law. GRIIS — the Global Register of Introduced and Invasive Species — lists the plant as invasive in the lower 48 states. Most invasive plants carry no state listing at all and are sold freely, so a plant without this tag is not thereby safe, and a plant without a legal chip is not thereby harmless.
Prohibited
May not be sold, moved, propagated or possessed at all.
Restricted
May still be sold or held, but under conditions — retail signage, an identification tag, or a carve-out for sterile cultivars.
Listed
Designated, but the duty to control it falls on landowners rather than on the nursery trade.

Where this comes from

Connecticut listings
Conn. Gen. Stat. 22a-381d (as amended by P.A. 24-11). Read the rule.
Invasive status
GRIIS, the Global Register of Introduced and Invasive Species, via GBIF, covering the lower 48 states. A scientific register with no legal force; it is cited separately from the statute above because the two disagree far more often than they agree. Garden crops it flags only for spreading from cultivation are left out after review.
Status wording
The Prohibited / Restricted / Listed chips are Ezina’s normalisation across 44 states and are not the legal term. Where Connecticut’s own word for a plant differs from the chip, it is quoted verbatim beneath it.
Nativity
USDA PLANTS county distribution layer, surfaced through the county checker.

Regulated next door, but not in Connecticut

Plants that two or more states bordering Connecticut regulate, and Connecticut does not. A listing is a legal act rather than an ecological one, so a plant can be a documented problem here and still be sold here.

Questions

Is there an official Connecticut invasive species list?

Yes. Conn. Gen. Stat. 22a-381d (as amended by P.A. 24-11) is Connecticut's list, naming 60 plants under a trade restriction, which governs what may be sold, propagated, or moved within the state — in plain terms, which plants are illegal to sell here. GRIIS, the Global Register of Introduced and Invasive Species, flags 53 of these 60 as invasive in the lower 48 states. That is an ecological finding, not a ruling by Connecticut. This page shows both side by side.

What plants are illegal to sell in Connecticut?

60 plants are regulated under Conn. Gen. Stat. 22a-381d (as amended by P.A. 24-11). Plants marked Prohibited may not be sold, propagated, or moved within Connecticut. Plants marked Restricted carry narrower limits set by the rule.

Is my plant invasive in Connecticut?

Search the table on this page for Connecticut's legal determination, then look for the Invasive chip beside it, which is a separate ecological finding from GRIIS rather than a ruling by Connecticut. A plant can carry one, both, or neither. For an address-level answer, enter the plant's name in Ezina's checker to get its Connecticut status alongside whether USDA records it as native to your specific county. Every answer links the record it came from.

Is it illegal to plant these in Connecticut?

For the plants marked Prohibited, Conn. Gen. Stat. 22a-381d (as amended by P.A. 24-11) bars selling, propagating, or moving them within Connecticut. Whether planting one you already own is itself an offence depends on that rule's exact wording, which is why every plant on this page links the citation rather than us paraphrasing it. Plants marked Restricted carry narrower limits the rule sets out.

Does a plant missing from this list mean it is safe to plant in Connecticut?

No. This page reproduces what Connecticut regulates, and a state list is a legal instrument rather than an ecological verdict. Plenty of plants spread aggressively without ever being listed, and states add species years after the problem is documented.

Grow natives easily with Ezina

How it works

We provide the tools you need to succeed.

The Ezina app identifying a plant: a live camera view framing pink coneflowers, with Plant, Disease/Insect, and Both scan modes.
010.1Identify

Add a plant

Snap a photo or type the name. Ezina matches it to a library of about 40,000 species and starts a care plan tailored to your zone, the local weather, and the time of year.

The Ezina app’s care screen: water needs showing status Okay, last watered 12 days ago, a suggested volume, and a treatment section.
010.2Care

Get a care plan

A schedule built from local rain, temperature, and sun, not a fixed weekly cadence. You get a single notification when a plant actually needs water. Easily add treatments for diseases and pests.

The Ezina Dig planner: a starting-plan site map with suggested garden beds you can draw with your finger.
010.3Plan

Explore new options

Our garden planner Dig helps you understand what works best for your location and makes suggestions based off your long term goals.

Add a plant

Snap a photo or type the name. Ezina matches it to a library of about 40,000 species and starts a care plan tailored to your zone, the local weather, and the time of year.

Compiled from peer-reviewed research, USDA documentation,
and direct scientific observation across the United States.

Leave a forwarding address
To be read on:Read on: