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 updated in October 2024 in accordance with Public Act No. 24-11.
(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
Recent Additions
Added to Invasive Plant List May 14, 2024; Prohibition from importation, movement, sale, purchase, transplanting, cultivation and distribution effective October 1, 2024 (under CT General Statutes Public Act No. 24-11):
Japanese angelica tree – Aralia elata
Growth form or habit: Tree
Prohibited by statute? Yes (Effective Oct. 2024)
CalPhotos - Japanese angelica tree
Quackgrass – Elymus repens (L.) Gould
Growth form or habit: Grass or grass-like
Prohibited by statute? Yes (Effective Oct. 2024)
Japanese wisteria – Wisteria floribunda (P)
Growth form or habit: Woody Vine
Prohibited by statute? Yes (Effective Oct. 2024)
Chinese wisteria – Wisteria sinensis (P)
Growth form or habit: Woody vine
Prohibited by statute? Yes (Effective Oct. 2024)
Added to Invasive Plant List May 14, 2024; Prohibition from importation, movement, sale, purchase, transplanting, cultivation and distribution effective October 1, 2027 (under CT General Statutes Public Act No. 24-11):
October 2027: Callery pear – Pyrus calleryana
Growth form or habit: Tree
Prohibited by statute? Yes (Effective Oct. 2027)
Invasive Plant List (Sorted by Botanical Name)
Click here to view the list sorted by COMMON NAME
Acer ginnala – Amur maple (P)
Growth form or habit: Tree
Prohibited by statute? N/A
Invasive.org - Amur maple photos
Acer platanoides – Norway maple
Growth form or habit: Tree
Prohibited by statute? N/A
Invasive.org - Norway maple photos
NY Invasive- Norway maple ID and mgmt.
Acer pseudoplatanus – Sycamore maple (P)
Growth form or habit: Tree
Prohibited by statute? Yes
Invasive.org - Sycamore maple photos
Aegopodium podagraria – Goutweed/Bishops Weed
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Goutweed factsheet
Invasive.org - Goutweed photos
Ailanthus altissima – Tree of Heaven
Growth form or habit: Tree
Prohibited by statute? Yes
Elimination of Ailanthus - Picone 2024
Invasive.org - Tree of heaven photos
PSU- Tree of heaven identification sheet
PSU Ext - Tree of heaven factsheet
Alliaria petiolata – Garlic mustard
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Garlic mustard photos
MSU - Garlic mustard factsheet
USDA - Garlic mustard identification sheet
PSU - Garlic mustard factsheet
Amorpha fruticosa – False indigo (P)
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - False indigo photos
Ampelopsis brevipedunculata – Porcelainberry
Growth form or habit: Woody Vine
Prohibited by statute? Yes (Effective October 1, 2024)
Invasive.org - Porcelainberry photos
Maryland Extension - Porcelainberry identification sheet
Artemisia vulgaris – Mugwort
Growth form or habit: Herbaceous
Prohibited by statute? Yes (Effective October 1, 2024)
WVU Extension- Mugwort identification sheet
UConn/CIPWG - Mugwort factsheet
UConn IPM - Mugwort ID and control factsheet
Arthraxon hispidus – Hairy jointgrass (P)
Growth form or habit: Grass or grass-like
Prohibited by statute? Yes
Invasive Plant Atlas- Hairy jointgrass factsheet
Invasive.org - Hairy jointgrass photos
Bassia scoparia – Common kochia (P)
Berberis thunbergii – Japanese barberry
Growth form or habit: Shrub
Prohibited by statute? N/A
Invasive.org - Japanese barberry photos
Maine - Japanese barberry factsheet
Michigan - Japanese barberry factsheet
PA - Japanese barberry factsheet
UConn IPM - Japanese barberry factsheet
Berberis vulgaris – Common barberry
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Common barberry photos
MDA State - Common barberry factsheet
UMN EXT - Common barberry factsheet
Bromus tectorum – Drooping brome-grass (P)
Growth form or habit: Grass or grass-like
Prohibited by statute? Yes
Go Botany - Drooping brome-grass
Invasive.org - Drooping brome-grass photos
USDA - Drooping brome-grass factsheet
PA - Drooping brome-grass factsheet
Butomus umbellatus – Flowering rush (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
Department of Natural Resources - Flowering rush factsheet
Invasive.org - Flowering rush photos
Cabomba caroliniana – Fanwort
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
Callitriche stagnalis – Pond water-starwort (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
Go Botany- Pond water-starwort factsheet
Go Botany - Pond water-starwort
Cardamine impatiens – Narrowleaf bittercress
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Go Botany - Narrowleaf bittercress
Invasive.org - Narrowleaf bittercress factsheet
Minnesota Department Of Agriculture - Narrowleaf bittercress identification sheet
Paen flowered - Narrowleaf bittercress photos
UMN EXT - Narrowleaf bittercress factsheet
Carex kobomugi – Japanese sedge (P)
Growth form or habit: Grass of grass-like
Prohibited by statute? Yes
Invasive Plant Atlas - Japanese sedge identification sheet
Celastrus orbiculatus – Asiatic bittersweet
Growth form or habit: Woody vine
Prohibited by statute? Yes
Go Botany - Asiatic bittersweet
Invasive.org - Asiatic bittersweet photos
Mich State - Asiatic bittersweet factsheet
USDA - Asiatic bittersweet identification
PSU - Asiatic bittersweet factsheet
UConn IPM - Asiatic bittersweet ID and control factsheet
Centaurea stoebe – Spotted knapweed
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Cornell - Spotted knapweed identification sheet
USDA - Spotted knapweed factsheet
Cirsium arvense – Canada Thistle (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Canada thistle photo
USDA - Canada thistle identification sheet
University Of Minnesota - Canada thistle factsheet
Cynanchum louiseae – Black swallow-wort (syn. Vincetoxicum nigrum)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Go Botany - Black swallow-wort
Invasive.org - Black swallow-wort photos
Invasive.org - Black swallow-wort identification sheet
PA - Black swallow-wort factsheet
Cynanchum rossicum – Pale swallow-wort (syn. Vincetoxicum rossicum)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Pale swallow-wort photos
Wisconsin- Pale swallow-wort identification sheet
Invasive - Pale swallow-wort factsheet
Datura stramonium – Jimsonweed (P)
Egeria densa – Brazilian water-weed (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
USDA - Brazilian water-weed factsheet
CIPWG - Brazilian water-weed photos
Go Botany - Brazilian water-weed
Invasive.org - Brazilian water-weed photos
Chesapeake Bay Program- Brazilian water-weed factsheet
Invasive Plant Atlas- Brazilian water-weed identification sheet
PA DCNR - Brazilian water-weed factsheet
RI - Brazilian water-weed factsheet
Eichhornia crassipes – Common water-hyacinth (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? N/A
USGS - Common water-hyacinth factsheet
Go Botany - Common water-hyacinth
Invasive.org - Common water-hyacinth photos
NOAA - Common water-hyacinth identification sheet
Elaeagnus angustifolia – Russian olive (P)
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Russian olive photos
Elaeagnus umbellata – Autumn olive
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Autumn olive photos
Mich State - Autumn olive factsheet
PA DCNR - Autumn olive factsheet
Elsholtzia ciliata – Crested late-summer mint (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Go Botany - Crested late-summer mint
Euonymus alatus – Winged euonymus
Growth form or habit: Shrub
Prohibited by statute? N/A
Invasive.org - Winged euonymus photos
Eco land scaping - Winged euonymus identification sheet
Euphorbia cyparissias – Cypress spurge (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Cypress spurge photos
Euphorbia esula – Leafy spurge
Frangula alnus – Glossy buckthorn
Growth form or habit: Shrub
Prohibited by statute? N/A
PSU - Glossy buckthorn factsheet
Invasive.org - Glossy buckthorn photos
Mich State - Glossy buckthorn factsheet
Froelichia gracilis – Slender snake cotton
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Go Botany - Slender snake cotton
Glechoma hederacea – Ground ivy (P)
Glyceria maxima – Reed mannagrass (P)
Growth form or habit: Grass of grass-like
Prohibited by statute? Yes
EDD Maps - Reed mannagrass factsheet
Heracleum mantegazzianum – Giant hogweed (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
CIPWG - Giant hogweed factsheet
Hesperis matronalis – Dame’s rocket
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Humulus japonicus – Japanese hops (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Japanese hops photos
Hydrilla verticillata – Hydrilla
Impatiens glandulifera – Ornamental jewelweed (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
EDD Maps - Ornamental jewelweed factsheet
Go Botany - Ornamental jewelweed
Invasive.org - Ornamental jewelweed photos
Maine - Ornamental jewelweed identification sheet
Iris pseudacorus – Yellow iris
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
Invasive.org - Yellow iris photos
Invasive Plant Atlas - Yellow iris identification sheet
Lepidium latifolium – Perennial pepperweed
Growth form or habit: Herbaceous
Prohibited by statute? Yes
EDD Maps - Perennial pepperweed factsheet
Go Botany - Perennial pepperweed
Ligustrum obtusifolium – Border privet (P)
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Border privet photos
Ligustrum ovalifolium – California privet (P)
Growth form or habit: Shrub
Prohibited by statute? N/A
EDD Maps - California privet factsheet
Invasive.org- California privet photos
Invasive Plant Atlas- California privet identification sheet
Ligustrum vulgare – European privet (P)
Growth form or habit: Shrub
Prohibited by statute? N/A
Invasive.org - European privet photos
Lonicera japonica – Japanese honeysuckle
Growth form or habit: Woody vine
Prohibited by statute? Yes
UConn IPM - Japanese honeysuckle factsheet
Go Botany - Japanese honeysuckle
Invasive.org - Japanese honeysuckle photos
Maine - Japanese honeysuckle factsheet
USDA - Japanese honeysuckle identification sheet
UConn - Japanese honeysuckle identification sheet
PA DCNR - Japanese honeysuckle factsheet
Lonicera maackii – Amur honeysuckle
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Amur honeysuckle photos
Maine - Amur honeysuckle factsheet
Lonicera morrowii – Morrow’s honeysuckle
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
Invasive Plant Atlas - Morrow's honeysuckle identification sheet
PA DCNR - Morrow's honeysuckle factsheet
TNC - Morrow's honeysuckle factsheet
Lonicera tatarica – Tatarian honeysuckle (P)
Growth form or habit: Shrub
Prohibited by statute? Yes
Go Botany - Tatarian honeysuckle
Invasive.org - Tatarian honeysuckle photos
Maine - Tatarian honeysuckle factsheet
WIGL - Tatarian honeysuckle identification sheet
Lonicera x bella – Belle honeysuckle
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Belle honeysuckle photos
Virginia Tech - Belle honeysuckle identification sheet
PSU - Belle honeysuckle factsheet
Lonicera xylosteum – Dwarf honeysuckle (P)
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Dwarf honeysuckle photos
Lychnis flos-cuculi – Ragged robin (P)
Lysimachia nummularia – Moneywort (P)
Lysimachia vulgaris – Garden loosestrife (P)
Growth form or habit: Herbacous
Prohibited by statute? Yes
Go Botany - Garden loosestrife
Invasive.org - Garden loosestrife photos
Edd Maps - Garden loosestrife factsheet
Lythrum salicaria – Purple loosestrife
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
Go Botany - Purple loosestrife
Invasive.org - Purple loosestrife photos
Maine - Purple loosestrife factsheet
USDA - Purple loosestrife identification sheet
Marsilea quadrifolia – European waterclover (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
Go Botany - European waterclover
Invasive.org - European waterclover photos
Microstegium vimineum – Japanese stiltgrass
Growth form or habit: Grass or grass-like
Prohibited by statute? Yes
Go Botany - Japanese stiltgrass
Invasive.org - Japanese stiltgrass photos
PA - Japanese stiltgrass factsheet
USDA - Japanese stiltgrass identification sheet
UConn IPM - Japanese stiltgrass factsheet
Miscanthus sinensis – Eulalia (P)
Growth form or habit: Grass or grass-like
Prohibited by statute? N/A
Myosotis scorpioides – Forget-me-not
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Forget-me-not factsheet
Edd Maps - Forget-me-not factsheet
Myriophyllum aquaticum – Parrotfeather (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CAES - Parrotfeather factsheet
Invasive.org - Parrotfeather photos
PA DCNR - Parrotfeather factsheet
Myriophyllum heterophyllum – Variable-leaf watermilfoil
Growth form or habit: Aquatic or wetland
Prohibited by statute? Yes
Aqua Plant- Variable-leaf watermilfoil identification photos
CAES - Variable-leaf watermilfoil factsheet
Go Botany - Variable-leaf watermilfoil
Invasive.org - Variable-leaf watermilfoil photos
Myriophyllum spicatum – Eurasian watermilfoil
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
Go Botany - Eurasian watermilfoil
Invasive.org - Eurasian watermilfoil photos
Maine - Eurasian watermilfoil factsheet
PA DCNR - Eurasian watermilfoil factsheet
Najas minor – Brittle water-nymph (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
Go Botany - Brittle water-nymph
Invasive.org - Brittle water-nymph photos
Nasturtium microphyllum – Onerow yellowcress (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
EDD Maps - Onerow yellow-cress
Invasive.org - Onerow yellow-cress photos
USDA- Onerow yellowcress factsheet
Nasturtium officinale – Watercress (P)
Growth form or habit: Aquatic or wetland
Prohibited by statute? Yes
Nelumbo lutea – American water lotus (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
Aqua Plant- American water lotus identification sheet
CAES - American water lotus factsheet
Nymphoides peltata – Yellow floating heart (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
Go Botany - Yellow floating heart
Invasive.org - Yellow floating heart photos
Edd Maps - Yellow floating heart factsheet
USGS- Yellow floating heart factsheet
Onopordum acanthium – Scotch thistle (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Scotch thistle photos
Ornithogalum umbellatum – Star-of-Bethlehem (P)
Growth form or habit: Herbaceous
Prohibited by statute? N/A
Edd Maps - Star-of-Bethlehem factsheet
Grow Native- Star-of-Bethlehem factsheet
Invasive.org - Star-of-Bethlehem photos
Paulownia tomentosa – Princess tree (P)
Growth form or habit: Tree
Prohibited by statute? Yes
Invasive.org - Princess tree photos
Phalaris arundinacea – Reed canary grass
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
USGS - Reed canary grass identification sheet
Phragmites australis – Common reed
Growth form or habit: Grass or grass-like
Prohibited by statute? Yes
Invasive.org - Common reed photos
UConn - Common reed identification sheet
Pistia stratiotes – Water lettuce (P)
Growth form or habit: Aquatic or wetland
Prohibited by statute? N/A
CAES - Water lettuce factsheet
Poa compressa – Canada bluegrass (P)
Growth form or habit: Grass or grass-like
Prohibited by statute? Yes
Edd Maps - Canada bluegrass factsheet
Polygonum caespitosum – Bristled knotweed
Polygonum cuspidatum – Japanese knotweed (syn. Reynoutria japonica and Fallopia japonica)
Polygonum perfoliatum (Persicaria perfoliata) – Mile-a-minute vine
Growth form or habit: Herbaceous
Prohibited by statute? Yes
USDA - MAM identification sheet
Polygonum sachalinense – Giant knotweed (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Giant knotweed photos
Populus alba – White poplar (P)
Potamogeton crispus – Curly-leafed pondweed
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
USGS - Curly-leaf pondweed factsheet
Go Botany - Curly-leaf pondweed
Invasive.org - Curly-leaf pondweed photos
USGS - Curly-leaf pondweed identification sheet
PSU EXT - Curly-leaf pondweed factsheet
Pueraria montana – Kudzu (P)
Ranunculus ficaria – Fig buttercup (syn. Ficaria verna)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Fig buttercup photos
Rhamnus cathartica – Common buckthorn
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Common buckthorn photos
Maine - Common buckthorn factsheet
Robinia pseudoacacia – Black locust
Growth form or habit: Tree
Prohibited by statute? N/A
Invasive.org - Black locust photos
Minnesota DOA - Black locust factsheet
Rosa multiflora – Multiflora rose
Growth form or habit: Shrub
Prohibited by statute? Yes
Invasive.org - Multiflora rose photos
Maine - Multiflora rose factsheet
PSU - Multiflora rose factsheet
Rosa rugosa – Rugosa rose (P)
Rubus phoenicolasius – Wineberry
Rumex acetosella – Sheep sorrel (P)
Salvinia molesta – Giant salvinia (P)
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CABI - Giant salvinia factsheet
Senecio jacobaea – Tansy ragwort (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Invasive.org - Tansy ragwort photos
WA NWCB - Tansy ragwort factsheet
Silphium perfoliatum – Cup plant (P)
Solanum dulcamara – Bittersweet nightshade (P)
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Go Botany - Bittersweet nightshade
Trapa natans – Water chestnut
Growth form or habit: Aquatic and wetland
Prohibited by statute? Yes
CT River - Water chestnut factsheet
Invasive.org - Water chestnut photos
Tussilago farfara – Coltsfoot
Growth form or habit: Herbaceous
Prohibited by statute? Yes
Edd Maps - Coltsfoot factsheet
Invasive.org - Coltsfoot photos
Valeriana officinalis – Garden heliotrope (P)
*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