Connecticut Invasive Plant List

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

Invasive Plant List (Sorted by Common Name)

Click here to view the list sorted by BOTANICAL NAME

California privet flowers and foliage, L. Mehrhoff

California privet – Ligustrum ovalifolium (P)

Poa compressa. L. Mehrhoff

Canada bluegrass – Poa compressa (P)

Cirsium arvense flowers. A. Siegel-Miles

Canada Thistle – Cirsium arvense (P)

Tussilago farfara foliage. L. Mehrhoff

Coltsfoot – Tussilago farfara

Euphorbia cyparissias flowers and foliage. L. Mehrhoff

Cypress spurge – Euphorbia cyparissias (P)

Hesperis matronalis flowers. A Siegel-Miles

Dame’s rocket – Hesperis matronalis

Growth form or habit: Herbaceous 

Prohibited by statute? Yes

Go Botany - Dame's rocket - Dame's rocket

NRCS-1 - Dame's rocket

OSU - Dame's rocket

Bromus tectorum. L. Merhroff

Drooping brome-grass – Bromus tectorum (P)

Lonicera xylosteum flowers and foliage, L. Mehrhoff

Dwarf honeysuckle – Lonicera xylosteum (P)

Amorpha fruticosa leaves and flowers. L. Mehrhoff

False indigo – Amorpha fruticosa (P)

Cabomba caroliniana foliage. L. Mehrhoff

Fanwort – Cabomba caroliniana

Growth form or habit: Aquatic and wetland

Prohibited by statute? Yes

CAES - Fanwort factsheet

Go Botany - Fanwort - Fanwort photos

Maine - Fanwort factsheet

PA DCNR - Fanwort factsheet




Ranunculus ficaria foliage and flowers. L. Mehrhoff

Fig buttercup – Ranunculus ficaria (syn. Ficaria verna)

Butomus umbellatus. L. Mehrhoff

Giant hogweed flower. L. Mehrhoff

Giant hogweed – Heracleum mantegazzianum (P)

Polygonum sachalinense foliage and flowers. L. Mehrhoff

Giant knotweed – Polygonum sachalinense (P)

Salvinia molesta foliage. L. Mehrhoff

Giant salvinia – Salvinia molesta (P)

Aegopodium podagraria foliage. A. Siegel-Miles

Goutweed/Bishops Weed – Aegopodium podagraria

Glechoma hederacea flowers and foliage. A Siegel-Miles

Ground ivy – Glechoma hederacea (P)

Growth form or habit: Herbaceous 

Prohibited by statute? Yes

Go Botany - Ground ivy - Ground ivy photos

USDA - Ground ivy factsheet

Arthraxon hispidus foliage. L. Mehrhoff.

Hairy jointgrass – Arthraxon hispidus (P)

Growth form or habit: Grass or grass-like

Prohibited by statute? Yes

Go Botany - Hairy jointgrass - Hairy jointgrass factsheet - Hairy jointgrass photos


Hydrilla foliage. L. Mehrhoff

Hydrilla – Hydrilla verticillata

Humulus japonicus foliage. L. Mehrhoff

Japanese hops – Humulus japonicus (P)

Polygonum cuspidatum flowers and foliage. A Siegel-Miles

Japanese knotweed – Polygonum cuspidatum (syn. Reynoutria japonica and Fallopia japonica)

Euphorbia esula foliage and flowers. L. Mehrhoff

Leafy spurge – Euphorbia esula

Growth form or habit: Herbaceous

Prohibited by statute? Yes

Go Botany - Leafy spurge - Leafy spurge photos

USDA - Leafy spurge factsheet

Mile a minute vine. L. Mehrhoff

Mile-a-minute vine – Polygonum perfoliatum (Persicaria perfoliata)

Moneywort flowers. L. Mehrhoff

Moneywort – Lysimachia nummularia (P)

Growth form or habit: Herbaceous

Prohibited by statute? N/A

Go Botany - Moneywort - Moneywort photos

PA DCNR - Moneywort factsheet

Lepidium latifolium flowers and foliage. L. Mehrhoff

Perennial pepperweed – Lepidium latifolium

Callitriche stagnalis infestation. L. Mehrhoff

Pond water-starwort – Callitriche stagnalis (P)

Porcelainberry. V. Wallace

Porcelainberry – Ampelopsis brevipedunculata

Glyceria maxima. L. Mehrhoff

Reed mannagrass – Glyceria maxima (P)

Rosa rugosa fruit, foliage, and flowers. L. Mehrhoff

Rugosa rose – Rosa rugosa (P)

Growth form or habit: Shrub 

Prohibited by statute? N/A

Go Botany - Rugosa rose - Rugosa rose photos

USDA - Rugosa rose factsheet

Onopordum acanthium flower. L. Mehrhoff

Scotch thistle – Onopordum acanthium (P)

Rumex acetosella. A. Siegel-Miles

Sheep sorrel – Rumex acetosella (P)

Growth form or habit: Herbaceous  

Prohibited by statute? Yes

Go Botany - Sheep sorrel - Sheep sorrel photos

Froelichia gracilis along road. L. Mehrhoff

Slender snake cotton – Froelichia gracilis

Ornithogalum umbellatum flowers. L. Mehrhoff

Star-of-Bethlehem – Ornithogalum umbellatum (P)

Populus alba, L. Mehrhoff

White poplar – Populus alba (P)

Rubus phoenicolasius foliage and fruit. L. Mehrhoff

Wineberry – Rubus phoenicolasius

Growth form or habit: Shrub

Prohibited by statute? Yes

Go Botany - Wineberry - Wineberry photos

PA DCNR - Wineberry factsheet


*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