Click below to view the Connecticut Invasive Plant List. The list includes Invasive and Potentially Invasive Plants as determined by the Connecticut Invasive Plants Council in accordance with Connecticut General Statutes §22a-381a through §22a-381d. The list was most recently re-printed in October 2018.
(P) indicates Potentially Invasive (all others are considered Invasive in Connecticut)
"Prohibited by Statute" indicates prohibited status in Connecticut:
Yes=prohibited from importation, movement, sale, purchase, transplanting, cultivation and distribution under CT General Statutes §22a-381d
N/A=not prohibited
Newly Added: October 1, 2024
Chinese wisteria – Wisteria sinensis (P)
Growth form or habit: Woody vine
Prohibited by statute? Yes (Effective Oct. 2024)
Japanese angelica tree – Aralia elata
Growth form or habit: Tree
Prohibited by statute? Yes (Effective Oct. 2024)
PA DCNR- Japanese angelica tree
Rutgers - Japanese angelica tree
Japanese wisteria – Wisteria floribunda (P)
Growth form or habit: Woody Vine
Prohibited by statute? Yes (Effective Oct. 2024)
Quackgrass – Elymus repens (L.) Gould
Growth form or habit: Grass or grass-like
Prohibited by statute? Yes (Effective Oct. 2024)
October 2027: Callery pear – Pyrus calleryana
Growth form or habit: Tree
Prohibited by statute? Yes (Effective Oct. 2027)
Invasive Plant List (Sorted by Common Name)
Click here to view the list sorted by BOTANICAL NAME
American water lotus – Nelumbo lutea (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - American water lotus factsheet
Go Botany - American water lotus
Amur honeysuckle – Lonicera maackii
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Amur honeysuckle photos
Maine - Amur honeysuckle factsheet
NRCS-2 - Amur honeysuckle identification sheet
Amur maple – Acer ginnala (P)
Growth form or habit: Tree
Prohibited by statute? N/A
Invasive.org - Amur maple photos
Autumn olive – Elaeagnus umbellata
Growth form or habit: Shrub
Prohibited by statute? Yes
CIPWG - Autumn olive factsheet
Invasive.org - Autumn olive photos
Maine - Autumn olive factsheet
Mich State - Autumn olive factsheet
NRCS-1 - Autumn olive identification sheet
NRCS-2 - Autumn olive identification sheet
PA DCNR - Autumn olive factsheet
Belle honeysuckle – Lonicera x bella
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Belle honeysuckle photos
NRCS-2 - Belle honeysuckle identification sheet
PA DCNR - Belle honeysuckle factsheet
Bittersweet nightshade – Solanum dulcamara (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Go Botany - Bittersweet nightshade
Black locust – Robinia pseudoacacia
Growth form or habit: Tree
Prohibited by statute? N/A
Invasive.org - Black locust photos
Black swallow-wort – Cynanchum louiseae (syn. Vincetoxicum nigrum)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Go Botany - Black swallow-wort
Invasive.org - Black swallow-wort photos
NRCS-1 - Black swallow-wort identification sheet
PA DCNR - Black swallow-wort factsheet
Border privet – Ligustrum obtusifolium (P)
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Border privet photos
Brazilian water-weed – Egeria densa (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Brazilian water-weed factsheet
CIPWG - Brazilian water-weed photos
Go Botany - Brazilian water-weed
Invasive.org - Brazilian water-weed photos
Maine - Brazilian water-weed factsheet
NRCS-1 - Brazilian water-weed identification sheet
PA DCNR - Brazilian water-weed factsheet
RI DEM - Brazilian water-weed factsheet
Bristled knotweed – Polygonum caespitosum
Brittle water-nymph – Najas minor (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Brittle water-nymph factsheet
Go Botany - Brittle water-nymph
California privet – Ligustrum ovalifolium (P)
Growth form or habit: Shrub
Prohibited by statute? N/A
EDD Maps - California privet factsheet
Canada bluegrass – Poa compressa (P)
Growth form or habit: Grass or grass-like
Prohibited by statute? Yes
Invasive.org - Canada thistle photos
Canada Thistle – Cirsium arvense (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Canada thistle photo
NRCS-2 - Canada thistle identification sheet
PA DCNR - Canada thistle factsheet
Coltsfoot – Tussilago farfara
Common barberry – Berberis vulgaris
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Common barberry photos
MDA State - Common barberry factsheet
UMN EXT - Common barberry factsheet
Common buckthorn – Rhamnus cathartica
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Common buckthorn photos
Maine - Common buckthorn factsheet
Common kochia – Bassia scoparia (P)
Common reed – Phragmites australis
Growth form or habit: Grass or grass-like
Prohibited by statute? Yes
Invasive.org - Common reed photos
NRCS-1 - Common reed identification sheet
NRCS-2 - Common reed identification sheet
PA DCNR - Common reed factsheet
Common water-hyacinth – Eichhornia crassipes (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? N/A
CAES - Common water-hyacinth factsheet
Go Botany - Common water-hyacinth
Invasive.org - Common water-hyacinth photos
NRCS-2 - Common water-hyacinth identification sheet
Crested late-summer mint – Elsholtzia ciliata (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Go Botany - Crested late-summer mint
Cup plant – Silphium perfoliatum (P)
Curly-leafed pondweed – Potamogeton crispus
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Curly-leaf pondweed factsheet
Go Botany - Curly-leaf pondweed
Invasive.org - Curly-leaf pondweed photos
NRCS-1 - Curly-leaf pondweed identification sheet
PSU EXT - Curly-leaf pondweed factsheet
Cypress spurge – Euphorbia cyparissias (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Cypress spurge photos
Dame’s rocket – Hesperis matronalis
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Drooping brome-grass – Bromus tectorum (P)
Growth form or habit: Grass or grass-like
Prohibited by statute? Yes
Go Botany - Drooping brome-grass
Invasive.org - Drooping brome-grass photos
NRCS - Drooping brome-grass factsheet
PA DCNR - Drooping brome-grass factsheet
Dwarf honeysuckle – Lonicera xylosteum (P)
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Dwarf honeysuckle photos
Eulalia – Miscanthus sinensis (P)
Growth form or habit: Grass or grass-like
Prohibited by statute? N/A
Eurasian watermilfoil – Myriophyllum spicatum
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Eurasian watermilfoil factsheet
Go Botany - Eurasian watermilfoil
Invasive.org - Eurasian watermilfoil photos
Maine - Eurasian watermilfoil factsheet
NRCS-1 - Eurasian watermilfoil identification sheet
PA DCNR - Eurasian watermilfoil factsheet
European privet – Ligustrum vulgare (P)
Growth form or habit: Shrub
Prohibited by statute? N/A
Invasive.org - European privet photos
European waterclover – Marsilea quadrifolia (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - European waterclover factsheet
Go Botany - European waterclover
False indigo – Amorpha fruticosa (P)
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - False indigo photos
Fanwort – Cabomba caroliniana
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
Fig buttercup – Ranunculus ficaria (syn. Ficaria verna)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Fig buttercup photos
Flowering rush – Butomus umbellatus (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Flowering rush factsheet
Invasive.org - Flowering rush photos
Forget-me-not – Myosotis scorpioides
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Forget-me-not factsheet
Invasive.org - Forget-me-not photos
Garden heliotrope – Valeriana officinalis (P)
Garden loosestrife – Lysimachia vulgaris (P)
Growth form or habit: Herbacous
Prohibited by statute? Yes
Go Botany - Garden loosestrife
Invasive.org - Garden loosestrife photos
IPANE - Garden loosestrife factsheet
Garlic mustard – Alliaria petiolata
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Garlic mustard photos
MSU - Garlic mustard factsheet
NRCS-2 - Garlic mustard identification sheet
TNC - Garlic mustard factsheet
Giant hogweed – Heracleum mantegazzianum (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
CIPWG - Giant hogweed factsheet
Giant knotweed – Polygonum sachalinense (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Giant knotweed photos
Giant salvinia – Salvinia molesta (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CABI - Giant salvinia factsheet
Glossy buckthorn – Frangula alnus
Growth form or habit: Shrub
Prohibited by statute? N/A
DEEP - Glossy buckthorn factsheet
Invasive.org - Glossy buckthorn photos
Mich State - Glossy buckthorn factsheet
NRCS-1 - Glossy buckthorn identification sheet
Goutweed/Bishops Weed – Aegopodium podagraria
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Goutweed factsheet
Invasive.org - Goutweed photos
Ground ivy – Glechoma hederacea (P)
Hairy jointgrass – Arthraxon hispidus (P)
Growth form or habit: Grass or grass-like
Prohibited by statute? Yes
Invasive.org - Hairy jointgrass factsheet
Invasive.org - Hairy jointgrass photos
Hydrilla – Hydrilla verticillata
Japanese barberry – Berberis thunbergii
Growth form or habit: Shrub
Prohibited by statute? N/A
Invasive.org - Japanese barberry photos
NRCS-1 - Japanese barberry identification sheet
NRCS-2 - Japanese barberry identification sheet
Maine - Japanese barberry factsheet
Mich State - Japanese barberry factsheet
PA DCNR - Japanese barberry factsheet
UConn IPM - Japanese barberry factsheet
Japanese honeysuckle – Lonicera japonica
Growth form or habit: Woody vine
Prohibited by statute? Yes
DEEP - Japanese honeysuckle factsheet
Go Botany - Japanese honeysuckle
Invasive.org - Japanese honeysuckle photos
Maine - Japanese honeysuckle factsheet
NRCS-1 - Japanese honeysuckle identification sheet
NRCS-2 - Japanese honeysuckle identification sheet
PA DCNR - Japanese honeysuckle factsheet
Japanese hops – Humulus japonicus (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Japanese hops photos
Japanese knotweed – Polygonum cuspidatum (syn. Reynoutria japonica and Fallopia japonica)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
DEEP - Japanese knotweed factsheet
Invasive.org - Japanese knotweed photos
Mich State - Japanese knotweed factsheet
NRCS-2 - Japanese knotweed identification sheet
Japanese sedge – Carex kobomugi (P)
Growth form or habit: Grass of grass-like
Prohibited by statute? Yes
NRCS-2 - Japanese sedge identification sheet
Japanese stiltgrass – Microstegium vimineum
Growth form or habit: Grass or grass-like
Prohibited by statute? Yes
Go Botany - Japanese stiltgrass
Invasive.org - Japanese stiltgrass photos
NRCS-1 - Japanese stiltgrass identification sheet
NRCS-2 - Japanese stiltgrass identification sheet
NH DoA - Japanese stiltgrass factsheet
PA DCNR - Japanese stiltgrass factsheet
Jimsonweed – Datura stramonium (P)
Kudzu – Pueraria montana (P)
Leafy spurge – Euphorbia esula
Mile-a-minute vine – Polygonum perfoliatum (Persicaria perfoliata)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
NRCS-1 - MAM identification sheet
Moneywort – Lysimachia nummularia (P)
Morrow’s honeysuckle – Lonicera morrowii
Growth form or habit: Shrub
Prohibited by statute? Yes
Go Botany - Morrow's honeysuckle
Invasive.org - Morrow's honeysuckle photos
Maine - Morrow's honeysuckle factsheet
NRCS-2 - Morrow's honeysuckle identification sheet
PA DCNR - Morrow's honeysuckle factsheet
TNC - Morrow's honeysuckle factsheet
Mugwort – Artemisia vulgaris
Growth form or habit: Herbaceous
Prohibited by statute? Yes (Effective October 1, 2024)
NRCS-2 - Mugwort identification sheet
UConn/CIPWG - Mugwort facstsheet
Multiflora rose – Rosa multiflora
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Multiflora rose photos
Maine - Multiflora rose factsheet
NRCS - Multiflora rose factsheet
NRCS-1 - Multiflora rose identification sheet
NRCS-2 - Multiflora rose identification sheet
PA DCNR - Multiflora rose factsheet
Narrowleaf bittercress – Cardamine impatiens
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Go Botany - Narrowleaf bittercress
Invasive.org - Narrowleaf bittercress factsheet
NRCS-2 - Narrowleaf bittercress identification sheet
PA DCNR - Narrowleaf bittercress photos
UMN EXT - Narrowleaf bittercress factsheet
Norway maple – Acer platanoides
Growth form or habit: Tree
Prohibited by statute? N/A
Invasive.org - Norway maple photos
Onerow yellowcress – Nasturtium microphyllum (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Onerow yellowcress factsheet
EDD Maps - Onerow yellow-cress
Go Botany - Onerow yellow-cress
Asiatic bittersweet – Celastrus orbiculatus
Growth form or habit: Woody vine
Prohibited by statute? Yes
Go Botany - Asiatic bittersweet
Invasive.org - Asiatic bittersweet photos
Mich State - Asiatic bittersweet factsheet
NRCS-1 - Asiatic bittersweet identification sheet
PSU - Asiatic bittersweet factsheet
UConn IPM - Asiatic bittersweet factsheet
Ornamental jewelweed – Impatiens glandulifera (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
EDD Maps - Ornamental jewelweed factsheet
Go Botany - Ornamental jewelweed
Invasive.org - Ornamental jewelweed photos
NRCS-2 - Ornamental jewelweed identification sheet
Pale swallow-wort – Cynanchum rossicum (syn. Vincetoxicum rossicum)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Pale swallow-wort photos
NRCS-1 - Pale swallow-wort identification sheet
PA DCNR - Pale swallow-wort factsheet
UConn IPM - Pale swallow-wort factsheet
Parrotfeather – Myriophyllum aquaticum (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Parrotfeather factsheet
Invasive.org - Parrotfeather photos
NRCS-1 - Parrotfeather identification sheet
NRCS-2 - Parrotfeather identification sheet
PA DCNR - Parrotfeather factsheet
Perennial pepperweed – Lepidium latifolium
Growth form or habit: Herbaceous
Prohibited by statute? Yes
EDD Maps - Perennial pepperweed factsheet
Go Botany - Perennial pepperweed
Pond water-starwort – Callitriche stagnalis (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Pond water-starwort factsheet
Go Botany - Pond water-starwort
Porcelainberry – Ampelopsis brevipedunculata
Growth form or habit: Woody Vine
Prohibited by statute? Yes (Effective October 1, 2024)
Invasive.org - Porcelainberry photos
NRCS-2 - Porcelainberry identification sheet
Princess tree – Paulownia tomentosa (P)
Growth form or habit: Tree
Prohibited by statute? Yes
Invasive.org - Princess tree photos
Purple loosestrife – Lythrum salicaria
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Purple loosestrife factsheet
Go Botany - Purple loosestrife
Invasive.org - Purple loosestrife photos
Maine - Purple loosestrife factsheet
NRCS-1 - Purple loosestrife identification sheet
NRCS-2 - Purple loosestrife identification sheet
PA DCNR - Purple loosestrife factsheet
Ragged robin – Lychnis flos-cuculi (P)
Reed canary grass – Phalaris arundinacea
Growth form or habit: Grass or grass-like
Prohibited by statute? N/A
DNR MN - Reed canary grass factsheet
Invasive.org - Reed canary grass photos
NRCS-2 - Reed canary grass identification sheet
Reed mannagrass – Glyceria maxima (P)
Growth form or habit: Grass of grass-like
Prohibited by statute? Yes
EDD Maps - Reed mannagrass factsheet
Rugosa rose – Rosa rugosa (P)
Russian olive – Elaeagnus angustifolia (P)
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Russian olive photos
Maine - Russian olive factsheet
NRCS-1 - Russian olive identification sheet
Scotch thistle – Onopordum acanthium (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Scotch thistle photos
Sheep sorrel – Rumex acetosella (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Slender snake cotton – Froelichia gracilis
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Go Botany - Slender snake cotton
Spotted knapweed – Centaurea stoebe
Growth form or habit: Herbaceous
Prohibited by statute? Yes
USDA - Spotted knapweed factsheet
PA DCNR - Spotted knapweed factsheet
Star-of-Bethlehem – Ornithogalum umbellatum (P)
Growth form or habit: Herbaceous
Prohibited by statute? N/A
Invasive.org - Star-of-Bethlehem photos
Sycamore maple – Acer pseudoplatanus (P)
Growth form or habit: Tree
Prohibited by statute? Yes
Invasive.org - Sycamore maple photos
Tansy ragwort – Senecio jacobaea (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Tansy ragwort photos
WA NWCB - Tansy ragwort factsheet
Tatarian honeysuckle – Lonicera tatarica (P)
Growth form or habit: Shrub
Prohibited by statute? Yes
Go Botany - Tatarian honeysuckle
Invasive.org - Tatarian honeysuckle photos
Maine - Tatarian honeysuckle factsheet
NRCS-2 - Tatarian honeysuckle identification sheet
Tree of Heaven – Ailanthus altissima
Growth form or habit: Tree
Prohibited by statute? Yes
Elimination of Ailanthus - Picone 2024
Invasive.org - Tree of heaven photos
NRCS-1 - Tree of heaven identification sheet
PSU Ext - Tree of heaven factsheet
Variable-leaf watermilfoil – Myriophyllum heterophyllum
Growth form or habit: Aquatic or wetland
Prohibited by statute? Yes
CAES - Variable-leaf watermilfoil factsheet
Go Botany - Variable-leaf watermilfoil
Invasive.org - Variable-leaf watermilfoil photos
NRCS-1 - Variable-leaf watermilfoil identification photos
Water chestnut – Trapa natans
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Water chesnut factsheet
Invasive.org - Water chesnut photos
Maine - Water chesnut factsheet
NRCS-1 - Water chesnut identification sheet
NRCS-2 - Water chesnut identification sheet
Water lettuce – Pistia stratiotes (P)
Growth form or habit: Aquatic or wetland
Prohibited by statute? N/A
CAES - Water lettuce factsheet
Watercress – Nasturtium officinale (P)
Growth form or habit: Aquatic or wetland
Prohibited by statute? Yes
White poplar – Populus alba (P)
Wineberry – Rubus phoenicolasius
Winged euonymus – Euonymus alatus
Growth form or habit: Shrub
Prohibited by statute? N/A
Invasive.org - Winged euonymus photos
NRCS-1 - Winged euonymus identification sheet
Yellow floating heart – Nymphoides peltata (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Yellow floating heart factsheet
Go Botany - Yellow floating heart
Invasive.org - Yellow floating heart photos
IPANE - Yellow floating heart factsheet
Yellow iris – Iris pseudacorus
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
Invasive.org - Yellow iris photos
NRCS-2 - Yellow iris identification sheet
*CAES = Connecticut Agricultural Experiment Station; CIPWG = Connecticut Invasive Plant Working Group; DEEP = Connecticut Department of Energy and Environmental Protection; EDD Maps = Early Detection and Distribution Mapping System; IPANE = Invasive Plant Atlas of New England; Maine = University of Maine Cooperative Extension; Minnesota = Minnesota Department of Agriculture; MIPN = Midwest Invasive Plant Network; Montana = Montana State University Extension; NRCS = Natural Resource Conservation; PCA = Plant Conservation Alliance, National Park Service; PA DCNR = Pennsylvania Department of Conservation and Natural Resources; RI DEM = Rhode Island Department of Environmental Management; TNC = The Nature Conservancy; UC-Davis = University of California-Davis, Cooperative Extension & Agricultural Experiment Station; UConn = University of Connecticut; USFS = US Forest Service, United States Department of Agriculture; UF = University of Fla Extension; UNH = University of New Hampshire Extension; USDA = United States Department of Agriculture; WA NWCB = Washington State Noxious Weed Control Board