USA: Border States Plant Regulations

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U.S. Regulatory Approach

In 2016, U.S. Executive Order 1352 Safeguarding the Nation From the Impacts of Invasive Species identified invasive species as a national issue and established the National Invasive Species Council (NISC) to coordinate federal invasive species efforts and information sharing.

Federal authorities play a central role in regulating which plants may be imported into the country and which may be moved across state borders. Federal law does not regulate the sale of invasive plants. As a result, plants identified as invasive or listed as Federal Noxious Weeds may still be legally sold within a state if they are propagated locally, unless a state chooses to impose additional restrictions.

At the federal level, the U.S. Department of Agriculture (USDA) regulates plant importation and interstate movement under the Plant Protection Act (7 U.S.C. §§ 7701–7786, 2000) and the Federal Seed Act (7 U.S.C. §§ 1581–1610, 1939).

Under the Plant Protection Act (PPA), invasive plants may be designated as Federal Noxious Weeds (7 CFR Part 360), listed as Not Authorized Pending Pest Risk Analysis (NAPPRA) under the Plants for Planting regulations (7 CFR § 319.37-4), or regulated indirectly as hosts for other plant pests. These designations restrict importation into the United States and interstate movement, but they do not prohibit in-state propagation or sale.

Import requirements for plants for planting are set out in the Plants for Planting Manual (most recently updated in 2021), which details the conditions under which plants may enter the country.

The Federal Seed Act (FSA) governs agricultural and vegetable seed quality and labeling. It requires disclosure of weed seeds and sets zero tolerance for designated noxious weed seeds, while allowing states to impose additional restrictions.

Federal Noxious Weeds State noxious-weed seed requirements recognized in the adminstration of the Federal Seed Act (USDA, 2025):
💧 Aquatic and wetland weeds: mosquito fern or water velvet (Azolla pinnata), killer algae, Mediterranean strain (Caulerpa taxifolia), water hyacinth relative (Eichhornia azurea), hydrilla (Hydrilla verticillata), water-spinach or swamp morning-glory (Ipomoea aquatica), waterweed (Lagarosiphon major), ambulia (Limnophila sessiliflora), melaleuca or paperbark (Melaleuca quinquenervia), Monochoria species (Monochoria hastata, M. vaginalis), ottelia (Ottelia alismoides), arrowhead (Sagittaria sagittifolia), Salvinia species (Salvinia auriculata, S. biloba, S. herzogii, S. molesta), wetland nightshade (Solanum tampicense), and exotic bur-reed (Sparganium erectum).

Parasitic weeds: Aeginetia species (Aeginetia spp.), Alectra species (Alectra spp.), dodders (Cuscuta spp.), broomrapes (Orobanche spp.), and witchweeds (Striga spp.).

Terrestrial weeds: gum arabic tree or thorny acacia (Acacia nilotica), crofton weed (Ageratina adenophora, A. riparia), sessile joyweed (Alternanthera sessilis), capeweed (Arctotheca calendula), onionweed (Asphodelus fistulosus), animated oat or wild oat (Avena sterilis, including A. ludoviciana), wild safflower (Carthamus oxyacantha), pilipiliula (Chrysopogon aciculatus), Benghal dayflower (Commelina benghalensis), common crupina (Crupina vulgaris), African couchgrass or fingergrass (Digitaria abyssinica), velvet fingergrass or annual couchgrass (Digitaria velutina), lightning weed (Drymaria arenariodes), devil’s thorn (Emex spinosa), false caper or Geraldton carnation weed (Euphorbia terracina), goatsrue (Galega officinalis), giant hogweed (Heracleum mantegazzianum), Brazilian satintail (Imperata brasiliensis), cogongrass (Imperata cylindrica), British elecampane or British yellowhead (Inula britannica), murainograss (Ischaemum rugosum), African boxthorn (Lycium ferocissimum), maidenhair creeper (Lygodium flexuosum), Old World climbing fern (Lygodium microphyllum), melastoma (Melastoma malabathricum), mile-a-minute (Mikania cordata, M. micrantha), giant sensitive-plant (Mimosa diplotricha), catclaw mimosa (Mimosa pigra var. pigra), Onopordum thistles (Onopordum acaulon, O. illyricum), jointed prickly pear (Opuntia aurantiaca), red rice complex (Oryza longistaminata, O. punctata, O. rufipogon), Kodo-millet (Paspalum scrobiculatum), kikuyugrass (Pennisetum clandestinum), African feathergrass (Pennisetum macrourum), kyasumagrass (Pennisetum pedicellatum), missiongrass or thin napiergrass (Pennisetum polystachion), Prosopis species (Prosopis alpataco, P. argentina, P. articulata, P. burkartii, P. caldenia, P. calingastana, P. campestris, P. castellanosii, P. denudans, P. elata, P. farcta, P. ferox, P. fiebrigii, P. hassleri, P. humilis, P. kuntzei, P. pallida, P. palmeri, P. reptans, P. rojasiana, P. ruizlealii, P. ruscifolia, P. sericantha, P. strombulifera, P. torquata), itchgrass (Rottboellia cochinchinensis), wild blackberry complex (Rubus fruticosus complex) and wild raspberry (Rubus moluccanus), wild sugarcane (Saccharum spontaneum), wormleaf salsola (Salsola vermiculata), South African and Madagascar ragwort (Senecio inaequidens, S. madagascariensis), Spermacoce(Spermacoce alata), turkeyberry (Solanum torvum), tropical soda apple (Solanum viarum), coat buttons (Tridax procumbens), and liverseed grass (Urochloa panicoides).

A little more depth

No new taxa have been added to the Federal Noxious Weed List since 2010, although taxonomic updates have occurred. While the list includes some plants sold in the ornamental and horticultural trades, federal designation limits movement only. For example, cogon grass (Imperata cylindrica) is a Federal Noxious Weed that cannot be imported or moved across state lines, yet it may still be sold within a state if propagated locally, unless state law prohibits its sale. There are 87 terrestrial, 19 aquatic, and 5 parasitic taxa on Federal Noxious Weed List.

The USDA’s Animal and Plant Health Inspection Service (APHIS) serves as the United States’ National Plant Protection Organization under the International Plant Protection Convention (IPPC) and conducts pest and weed risk assessments in accordance with International Standards for Phytosanitary Measures (ISPMs). Weed Risk Assessments (WRAs) are publicly available.

Only plants that meet the U.S. interpretation of quarantine pest under ISPM 5-24 (pp. 25-27) or regulated non-quarantine can be subject to import restrictions (trade barriers). Therefore only high-risk species not yet present are typically placed on the NAPPRA list. There are currently 79 NAPPRA designated plant species; and 207 restricted taxa that may be hosts of other pests. An example of a prohibited plant is dwarf arrowhead (Sagittaria pygmaea) assessed as high-risk for both the U.S. and Canada. By contrast, fig buttercup (Ficaria verna) has also been assessed as a potential major invader across the U.S., but because it has already begun to naturalize in some states, it is considered beyond federal regulatory control and becomes a state problem. This is a widely recognized problem in the international community. (We discuss this issue in our white paper – pp. 19-23; 70).

Below is a summary of invasive plant regulations in the 13 U.S. states (including Alaska) that share a border with Canada. Because invasive plants do not respect political boundaries, understanding regulatory approaches in neighbouring jurisdictions helps identify shared risks. A spreadsheet summarizing plants regulated across these states (as of July 13, 2023) has been  uploaded. While errors may be present, links to primary sources are provided below and on the Canada: Province & Territories Plant Regulations page.

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Alaska AK

Regulatory approach

Alaska regulates invasive and noxious plants primarily under the Plant health and quarantine regulations (11 AAC 34), administered by the Alaska Department of Natural Resources (DNR), Division of Agriculture. Within this regulation, the Seed regulations (§ 11 AAC 34.010–11 AAC 34.090) and Pest control provisions (§ 11 AAC 34.100–11 AAC 34.190) establish the framework used to:

• set seed quality and labelling standards,
• maintain a noxious weed list governing seeds in commerce, and
• issue quarantines that prohibit the importation, movement, sale, or distribution of specified plant pests and plant materials
  (Alaska DNR, Plant Quarantine Summary, 2025).

What is regulated

🌱 24 regulated plant seeds — Prohibited and restricted noxious weeds (11 AAC 34.020)

Prohibited (seed regulation):
Russian knapweed (Acroptilon repens), whitetops and its varieties (Cardaria draba, C. pubescens, Lepidium latifolium), Canada thistle (Cirsium arvense), field bindweed (Convolvulus arvensis), quackgrass (Elymus repens), leafy spurge (Euphorbia esula), hempnettle (Galeopsis tetrahit), galinsoga (Galinsoga parviflora), orange hawkweed (Hieracium aurantiacum), blue-flowering lettuce (Lactuca pulchella), purple loosestrife (Lythrum salicaria), Austrian fieldcress (Rorippa austriaca), horsenettle (Solanum carolinense), and perennial sowthistle (Sonchus arvensis).

Restricted (seed contamination thresholds):
wild oats (Avena fatua), seven seeds per pound; mustard (Brassica juncea, Sinapis arvensis), 36 seeds per pound; blue burr (Lappula echinata), 18 seeds per pound; yellow toadflax (Linaria vulgaris), one seed per pound; buckhorn plantain (Plantago sp.), 90 seeds per pound; annual bluegrass (Poa annua), 90 seeds per pound; wild buckwheat (Polygonum convolvulus), two seeds per pound; radish (Raphanus raphanistrum), 27 seeds per pound; and tufted vetch (Vicia cracca), two seeds per pound.

⚠️ Important clarification:
Alaska’s noxious weed provisions regulate seed quality and contamination. They do not generally mandate eradication, control, or prohibit the sale of live plants once species are established in the landscape. This distinguishes Alaska’s approach from weed control acts used in many other jurisdictions.

🌳 2 terrestrial quarantine plants (Quarantine on mayday and chokecherry trees established, 2025)

• European bird cherry (Prunus padus) & chokecherry (Prunus virginiana)

💧 5 aquatic quarantine plants (Quarantine of aquatic invasive weeds, 2014)

• Brazilian waterweed (Egeria densa), Canadian waterweed (Elodea canadensis), western waterweed (Elodea nuttallii), hydrilla (Hydrilla verticillata), and Eurasian watermilfoil (Myriophyllum spicatum).

Key point: Alaska relies on quarantine authority under 11 AAC 34 to restrict the entry, transport, sale, and distribution of specified pests. This authority is species- and pathway-specific, not comprehensive.

Key limitations

• Regulation is fragmented, with no unified invasive plant statute addressing prevention, sales, and post-establishment impacts.
• Noxious weed rules focus on seed commerce and contamination, not ecological harm or landscape-level spread.
• Watchlists and rankings lack regulatory force, relying on voluntary compliance and education.

Learn more

The Alaska Center for Conservation Science developed a list of non-native plant species occurring in Alaska. Some have been screened using an invasiveness plant ranking system (Carson et al., 2008). Some of the ornamental plants ranked high-risk include: sneezeweed (Achillea ptarmica), goutweed (Aegopodium podagraria), European alder (Alnus glutinosa), lady’s mantle (Alchemilla mollis, A. monticola), meadow foxtail (Alopecurus pratensis), spineless plumeless thistle (Carduus acanthoides), Siberian pea shrub (Caragana arborescens), brass buttons (Cotula coronopifolia), Scotch broom (Cytisus scoparius), purple foxglove (Digitalis purpurea), knotweeds (Fallopia japonica, F. sachalinensis), ground ivy (Glechoma hederacea), baby’s-breath (Gypsophila paniculata), English ivy (Hedera helix), giant hogweed (Heracleum mantegazzianum), dame’s rocket (Hesperis matronalis), St. John’s wort (Hypericum perforatum), ornamental jewelweed (Impatiens glandulifera), yellow flag iris (Iris pseudacorus), white dead-nettle (Lamium album), oxeye daisy (Leucanthemum vulgare), toadflaxes (Linaria dalmatica, L. vulgaris), Tatarian honeysuckle (Lonicera tatarica), bigleaf lupine (Lupinus polyphyllus subsp. polyphyllus), loosestrifes (Lythrum salicaria, L. virgatum), mints (Mentha piperita, M. spicata), forget-me-nots (Myosotis scorpioides), American white waterlily (Nymphaea odorata), Iceland poppy (Papaver croceum), smartweeds (Persicaria lapathifolia, P. maculosa, P. wallichii), reed canarygrass (Phalaris arundinacea), rugosa rose (Rosa rugosa), bouncingbet (Saponaria officinalis), red campion (Silene dioica), cordgrasses (Spartina spp.), comfrey (Symphytum officinale), common mullein (Verbascum thapsus), and Johnny-jump-up (Viola tricolor).

The Strategic Plan for Invasive Weed & Agricultural Pest Management and Prevention in Alaska (2011) identified the need to improve regulations

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Idaho ID

Regulatory Overview

Within Idaho’s Agricultural and Horticultural Statutes (Title 22), invasive plants are regulated under an Invasive Species Act (C.19) and a Noxious Weeds regulation ( C. 24). Both statutes are administered by the Idaho Department of Agriculture under the Rules Governing Invasive Species and Noxious (IDAPA 02.06.09).

The Invasive Species Act regulates a limited number of high-risk plants associated with bioenergy or trap-cropping systems and prohibits their cultivation, transport, or release without a permit. Additional invasive plants are regulated under the Noxious Weeds Law, which applies more broadly to agricultural, horticultural, aquatic, and natural systems. No article containing noxious weed propagules may be sold within the state of Idaho.

What is regulated

🌱 7 invasive tax are regulated under the Invasive Species Act

• Regulated energy crops include giant reed (Arundo donax and hybrids), cold-tolerant eucalypts (Eucalyptus spp. and hybrids), purging nut (Jatropha curcas and hybrids), Chinese silvergrass (Miscanthus × giganteus and hybrids), and kudzu (Pueraria montana and hybrids).
• Regulated trap crops include black nightshade (Solanum nigrum and hybrids) and litchi tomato (Solanum sisymbriifoliumand hybrids).

🌱 ~74 invasive tax are regulated as Noxious Weeds

• Prohibited genera include all plants and plant parts, including all subtaxa, within the genera Cytisus, Genista, Spartium, and Chamaecytisus.
• Early Detection and Rapid Response (EDRR): feathered mosquito fern (Azolla pinnata), fanwort (Cabomba caroliniana), purple starthistle (Centaurea calcitrapa), Iberian starthistle (Centaurea iberica), squarrose knapweed (Centaurea triumfettii), Brazilian elodea (Egeria densa), water hyacinth (Eichhornia crassipes), goatsrue (Galega officinalis), giant hogweed (Heracleum mantegazzianum), yellow devil hawkweed (Hieracium glomeratum), tall hawkweed (Hieracium piloselloides), hydrilla (Hydrilla verticillata), common/European frogbit (Hydrocharis morsus-ranae), cogongrass (Imperata cylindrica), policeman’s helmet (Impatiens glandulifera), variable-leaf milfoil (Myriophyllum heterophyllum), starry stonewort (Nitellopsis obtusa), yellow floating heart (Nymphoides peltata), giant salvinia (Salvinia molesta), water chestnut (Trapa natans), and Syrian beancaper (Zygophyllum fabago).
• Control-listed species: Russian knapweed (Acroptilon repens), small bugloss (Anchusa arvensis), flowering rush (Butomus umbellatus), Turkish thistle (Carduus cinereus), musk thistle (Carduus nutans), meadow knapweed (Centaurea debeauxii), common crupina (Crupina vulgaris), Scotch broom (Cytisus scoparius), viper’s bugloss (Echium vulgare), orange hawkweed (Hieracium aurantiacum), yellow hawkweed (Hieracium caespitosum), black henbane (Hyoscyamus niger), dyer’s woad (Isatis tinctoria), parrotfeather milfoil (Myriophyllum aquaticum), Eurasian watermilfoil (Myriophyllum spicatum and hybrids), matgrass (Nardus stricta), common reed (phragmites) (Phragmites australis), Bohemian knotweed (Polygonum × bohemicum), Japanese knotweed (Polygonum cuspidatum), giant knotweed (Polygonum sachalinense), Mediterranean sage (Salvia aethiopis), perennial sowthistle (Sonchus arvensis), and Johnsongrass (Sorghum halepense).
• Containment-listed species: jointed goatgrass (Aegilops cylindrica), hoary alyssum (Berteroa incana), white bryony (Bryonia alba), whitetop or hoary cress (Cardaria draba), plumeless thistle (Carduus acanthoides), diffuse knapweed (Centaurea diffusa), yellow starthistle (Centaurea solstitialis), spotted knapweed (Centaurea stoebe), rush skeletonweed (Chondrilla juncea), Canada thistle (Cirsium arvense), poison hemlock (Conium maculatum), field bindweed (Convolvulus arvensis), houndstongue (Cynoglossum officinale), leafy spurge (Euphorbia esula), yellow flag iris (Iris pseudocorus), oxeye daisy (Leucanthemum vulgare), perennial pepperweed (Lepidium latifolium), Dalmatian toadflax (Linaria dalmatica ssp. dalmatica), yellow toadflax (Linaria vulgaris), purple loosestrife (Lythrum salicaria), milium (Milium vernale), Scotch thistle (Onopordum acanthium), curlyleaf pondweed (Potamogeton crispus), tansy ragwort (Senecio jacobaea), saltcedar (Tamarix spp.), and puncturevine (Tribulus terrestris).

💧 ~25 Noxious Weed could be considered aquatic or wetland-associated species

• Feathered mosquito fern (Azolla pinnata), fanwort (Cabomba caroliniana), Brazilian elodea (Egeria densa), water hyacinth (Eichhornia crassipes), hydrilla (Hydrilla verticillata), common/European frogbit (Hydrocharis morsus-ranae), cogongrass (Imperata cylindrica), policeman’s helmet (Impatiens glandulifera), variable-leaf milfoil (Myriophyllum heterophyllum), parrotfeather milfoil (Myriophyllum aquaticum), Eurasian watermilfoil (Myriophyllum spicatum and hybrids), starry stonewort (Nitellopsis obtusa), yellow floating heart (Nymphoides peltata), giant salvinia (Salvinia molesta), water chestnut (Trapa natans), flowering rush (Butomus umbellatus), matgrass (Nardus stricta), common reed (phragmites) (Phragmites australis), Bohemian knotweed (Polygonum × bohemicum), Japanese knotweed (Polygonum cuspidatum), giant knotweed (Polygonum sachalinense), yellow flag iris (Iris pseudocorus), purple loosestrife (Lythrum salicaria), curlyleaf pondweed (Potamogeton crispus), and saltcedar (Tamarix spp.).

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Maine ME

Regulatory Overview

Maine regulates invasive plants through several legal instruments: noxious-weed seed regulations, invasive-terrestrial plant rules, and an aquatic nuisance plant statute.

The Maine Seed Law (Maine Regulatory Statute 07-103, §1041-1043) establishes labelling requirements and limits the presence of noxious-weed seed. Products must indicate the presence by weight of weed seeds. Primary noxious weeds are prohibited. This is administered under he Dept. of Agriculture, Conservation and Forestry (DACF).

DACF is also responsible for implementing an administrate rule that explicitly regulates the sale of invasive terrestrial plants, entitled Criteria for listing invasive terrestrial plants (Code of Maine Rule. 01-001, c. 273) The rule prohibits the sale, import, export, propagation and distribution of plants that meet invasive criteria. To be listed, a plant must:

• be non-native to Maine;
• have the potential for rapid growth, dissemination, and establishment in minimally managed habitats;
• have the biological potential for widespread dispersion, including dispersal across spatial gaps;
• have the biological potential to occur in high numbers or large colonies in minimally managed habitats; and
• have the potential to displace native species in minimally managed habitats.

In addition a Watch List indicates plant with invasive potential that may become prohibited in five years, providing growers and retailers and opportunity to prepare. Plants may also be listed as Special Concern. These plants may be sold with labels that clearly indicate “Invasive Species – Harmful to the Environment.” Labels must also include non-invasive alternatives and provide instructions for preventing the spread of the labeled plant.

A third set of statutes are aimed a preventing the spread of invasive aquatic plants to protect water and navigation. The Dept. of Environmental Protection (DEP) oversees implementation of Aquatic nuisance species control  (M. R. S. 38, §419-C). This regulation prohibits the sale and transport of nuisance aquatic plants. In addition an Interagency Task Force on Invasive Aquatic Plants and Nuisance Species (M.R.S. 30-03 §1871) is required by law to develop an action plant to limit the spread of invasive plants and oversee control.

The Maine Horticultural Program ensures that healthy plant material is sold within and exported out of the state. Web portals provide Invasive Plants Information clearly indicating plants that are prohibited from sale, along with Grower Resources and Licensing and Inspection information. Nurseries are licensed and inspected to prevent the spread of pests and invasive plants ( Horticulture, M.R.S. 07-405 §2213).

What is regulated

🌱 ~15 noxious-weed taxa are regulated under the Maine Seed Law

• Prohibited: quackgrass (Elymus repens, syn. Agropyron repens), Canada thistle (Cirsium arvense), bindweed (Convolvulus arvensis), nut grass (Cyperus esculentus), and woundwort (Stachys palustris)
• Regulated: corncockle (Agrostemma githago), wild onion (Allium canadense), wild garlic (Allium vineale), yellow rocket (Barbarea vulgaris), wild mustard (Brassica spp.), dodder (Cuscuta spp.), buckhorn plantain (Plantago lanceolata), wild radish (Raphanus raphanistrum), horsenettle (Solanum carolinense), and perennial sowthistle (Sonchus arvensis)

🌱 ~63 invasive taxa are regulated under Criteria for listing invasive terrestrial plants (one requires labelling)

• Prohibited: amur maple (Acer ginnala), Norway maple (Acer platanoides), bishop’s weed (Aegopodium podagraria), tree of heaven (Ailanthus altissima), garlic mustard (Alliaria petiolata), European alder (Alnus glutinosa), false indigo bush (Amorpha fruticosa), porcelain berry (Ampelopsis glandulosa), woodland angelica (Angelica sylvestris), wild chervil (Anthriscus sylvestris), Japanese angelica tree (Aralia elata), common mugwort (Artemisia vulgaris), Japanese barberry (Berberis thunbergii), common barberry (Berberis vulgaris), flowering rush (Butomus umbellatus), Asiatic bittersweet (Celastrus orbiculatus), Russian olive (Elaeagnus angustifolia), autumn olive (Elaeagnus umbellata), burning bush (Euonymus alatus), wintercreeper (Euonymus fortunei), cypress spurge (Euphorbia cyparissias), silver lace vine (Fallopia baldschuanica), Japanese knotweed (Fallopia japonica), fine-leaved sheep fescue (Festuca filiformis), lesser celandine (Ficaria verna), glossy buckthorn (Frangula alnus), yellow hornpoppy (Glaucium flavum), creeping charlie (Glechoma hederacea), reed (great) mannagrass (Glyceria maxima), dame’s rocket (Hesperis matronalis), sea buckthorn (Hippophae rhamnoides), ornamental jewelweed (Impatiens glandulifera), yellow flag iris (Iris pseudacorus), border privet (Ligustrum obtusifolium), common privet (Ligustrum vulgare), Japanese honeysuckle (Lonicera japonica), amur (bush) honeysuckle (Lonicera maackii), Morrow’s honeysuckle (Lonicera morrowii), Tatarian honeysuckle (Lonicera tatarica), dwarf honeysuckle (Lonicera xylosteum), purple loosestrife (Lythrum salicaria), European wand loosestrife (Lythrum virgatum), stiltgrass (Microstegium vimineum), amur silvergrass (Miscanthus sacchariflorus), paulownia / princess tree (Paulownia tomentosa), mile-a-minute (Persicaria perfoliata), fuki / butterbur (Petasites japonicus), reed canary (ribbon) grass (Phalaris arundinacea), amur cork tree (Phellodendron amurense), photinia / Christmas berry (Photinia villosa), common reed (Phragmites australis), golden bamboo (Phyllostachys aurea), yellow grove bamboo (Phyllostachys aureosulcata), white cottonwood / white poplar (Populus alba), Callery / Bradford pear (Pyrus calleryana), creeping buttercup (Ranunculus repens), black locust (Robinia pseudoacacia), multiflora rose (Rosa multiflora), wineberry (Rubus phoenicolasius), cup plant (Silphium perfoliatum), European mountain ash (Sorbus aucuparia), coltsfoot (Tussilago farfara), common valerian (Valeriana officinalis).
• Special Concern: rugosa rose (Rosa rugosa)
• Watch List: hardy kiwi (Actinidia arguta), chocolate vine / five-leaf akebia (Akebia quinata), Italian arum (Arum italicum), paper mulberry (Broussonetia papyrifera), butterfly bush (Buddleja davidii), yam-leaved virgin’s bower / sweet autumn clematis (Clematis terniflora), Indian yam (Dioscorea oppositifolia), Chinese yam (Dioscorea polystachya), weeping lovegrass (Eragrostis curvula), queen of the meadow (Filipendula ulmaria), bicolor lespedeza / two-colored bush-clover (Lespedeza bicolor), California privet (Ligustrum ovalifolium), honeyberry / haskap (Lonicera caerulea), ragged robin (Lychnis flos-cuculi / Silene flos-cuculi), white mulberry (Morus alba), sawtooth oak (Quercus acutissima), rugosa rose / beach rose (Rosa rugosa), Ravenna grass / hardy pampas grass (Saccharum ravennae / Tripidium ravennae), sticky sage (Salvia glutinosa), milk thistle (Silybum marianum), Japanese spiraea (Spiraea japonica), sapphire-berry (Symplocos paniculata), Japanese tree lilac (Syringa reticulata), Chinese cedar (Toona sinensis), Siberian elm (Ulmus pumila), linden arrowwood (Viburnum dilatatum), Siebold viburnum (Viburnum sieboldii), Japanese wisteria (Wisteria floribunda), Chinese wisteria (Wisteria sinensis).

💧 ~11 invasive aquatic taxa are prohibited under Aquatic nuisance species control

• fanwort (Cabomba spp., including but not limited to Cabomba caroliniana), Brazilian elodea (Egeria densa), hydrilla (Hydrilla verticillata), European frog-bit (Hydrocharis morsus-ranae), nonindigenous water-milfoils (Myriophyllum spp., including Myriophyllum heterophyllum, variable-leaf water-milfoil; Myriophyllum spicatum, Eurasian water-milfoil; and Myriophyllum aquaticum, parrot feather), European naiad (Najas minor), yellow floating heart (Nymphoides peltata), curly pondweed (Potamogeton crispus), giant salvinia (Salvinia molesta), water soldier (Stratiotes aloides), water chestnut (Trapa spp., including but not limited to Trapa natans), swollen bladderwort (Utricularia inflata).

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Michigan MI

Regulatory Overview

Michigan invasive plant prevention regulations fall within three Acts: Michigan Seed Law Act, Michigan Noxious Weeds Act and Natural Resources and Environmental Protection Act.

As in other states, the Michigan Seed Law Act 329 of 1965 (MCL 286.701–715) ensure seed products are accurately labeled and exclude or restrict seeds from species of noxious weeds (including invasive species) specified in the Seed Law Implementation (Reg. 715) regulation.

The list of noxious-weed seed species associated with the Michigan Seed Law, does not align with the list of noxious weeds regulated under Michigan’s Noxious Weeds Act 247 of 1941 (MCL 247.61–72)  This Act specifies maintenance and control obligations for particular species like invasive giant hogweed (Heracleum mantegazzianum).

The Natural Resources and Environmental Protection Act 451 of 1994 Part 413 (MCL 324.41301–41341) regulates Transgenic and Non-native Species that have the potential to harm human health, or harm natural, agricultural, or silvicultural resources. There are additional special provisions regulating the sale or watercraft movement of aquatic invasive plants (NREPA 324, §324.41325, §324.41329)

Michigan recognizes and discourages the spread of many invasive plants, like tree-of-heaven (Ailanthus altissima) that are not currently not regulated – Invasive Plants.

What is regulated

🌱 Regulated noxious-weed seed taxa defined by Michigan Seed Law Implementation (Mich. Admin. Code R. 285.715)

• Prohibited: quackgrass (Agropyron repens, syn. Elytrigia repens), plumeless thistle (Carduus acanthoides), musk thistle (Carduus nutans), whitetop, hoary cress, or perennial peppergrass (Cardaria draba, syn. Lepidium draba), Russian knapweed (Centaurea picris), spotted knapweed (Centaurea maculosa, syn. Centaurea stoebe), Canada thistle (Cirsium arvense), bull thistle (Cirsium vulgare), field bindweed (Convolvulus arvensis), hedge bindweed (Convolvulus sepium), dodder (Cuscuta spp.), yellow nutsedge (Cyperus esculentus), leafy spurge (Euphorbia esula), morning glory (Ipomoea spp.), Johnsongrass (Sorghum halepense, including Sorghum almum and seed indistinguishable from Johnsongrass), perennial sowthistle (Sonchus arvensis), horsenettle (Solanum carolinense), puncturevine (Tribulus terrestris), and serrated tussock (Nasella trichotoma).
• Restricted noxious-weed seed: velvetleaf (Abutilon theophrasti), wild onion (Allium canadense), wild garlic (Allium vineale), wild oat (Avena fatua), yellow rocket (Barbarea vulgaris), hoary alyssum (Berteroa incana), black mustard (Brassica nigra), Indian mustard (Brassica juncea), wild carrot (Daucus carota), jimsonweed (Datura stramonium), buckhorn plantain (Plantago lanceolata), wild radish (Raphanus raphanistrum), curled dock (Rumex crispus), charlock (Sinapis arvensis), giant foxtail (Setaria faberi), bitter nightshade (Solanum dulcamara), black nightshade (Solanum nigrum), eastern black nightshade (Solanum ptychanthum), silverleaf or purple nightshade (Solanum elaeagnifolium), hairy nightshade (Solanum sarrachoides), nightshade complex (Solanum spp., including species with indistinguishable seed), and cocklebur (Xanthium strumarium).

🌱 Regulated noxious weeds requiring control under Michigan Noxious Weed Act (§247.62)

• Hoary alyssum (Berteroa incana), wild carrot (Daucus carota), bindweed (Convolvulus arvensis), Canada thistle (Cirsium arvense), dodders (any species of Cuscuta), mustards including charlock (Sinapis arvensis), black mustard (Brassica nigra), and Indian mustard (Brassica juncea), poison ivy (Toxicodendron radicans), poison sumac (Toxicodendron vernix, syn. T. vernix), ragweed (Ambrosia artemisiifolia, historically cited as Ambrosia elatior L.), perennial sowthistle (Sonchus arvensis), and giant hogweed (Heracleum mantegazzianum).

🌱 ~20 regulated Invasive taxa are mostly aquatic plants and terrestrial plants that impact wetlands regulated under NREPA, (§324.41301) 💧~19 aquatic taxa*

• Prohibited: fanwort (Cabomba caroliniana), cylindro (Cylindrospermopsis raciborskii), Brazilian elodea (Egeria densa, syn. Elodea densa), J giant hogweed (Heracleum mantegazzianum), European frogbit (Hydrocharis morsus-ranae), hydrilla (Hydrilla verticillata), African oxygen weed (Lagarosiphon major), parrot’s feather (Myriophyllum aquaticum), starry stonewort (Nitellopsis obtusa), yellow floating heart (Nymphoides peltata), apanese knotweed (Reynoutria japonica syn Fallopia japonica), giant salvinia (Salvinia molesta, S. auriculata, S. biloba, and S. herzogii), and water chestnut (Trapa natans).
• Restricted: flowering rush (Butomus umbellatus), autumn olive (Elaeagnus umbellata), purple loosestrife (Lythrum salicaria), Eurasian watermilfoil (Myriophyllum spicatum), common reed or phragmites (Phragmites australis), and curly-leaf pondweed (Potamogeton crispus).
  

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Minnesota MN

Regulatory Overview

Invasive plant prevention regulation in Minnesota falls three laws: Minnesota Seed Law (21.80 – 21.92), Minnesota Noxious Weed Law (18.75-18.91) and the Invasive Species law (84D.01-84D.15). The Departments of Agriculture (MDA) and Department of Natural Resources (MDNR) coordinate administration regulated species.

As with other seed laws, the central purpose is to ensure truthful labelling and seed quality. The prohibition or restriction of specified weed seed does reduce the spread of certain invasive plants. Minnesota updates regularly updates its list of Prohibited & Restricted Weed Seeds, 2025. No listed plants are purposely spread through the horticultural trades.

The Noxious Weed Law acknowledges the role of horticulture in spreading invasive plants and makes it illegal to possess, import, purchase, sell, propagate, transport, or introduce prohibited invasive plants (identified by DNR) and restricted noxious weeds (identify by MDA). Prohibited plants explicitly include the Federal Noxious Weed list, Minnesota and Federal Prohibited and Noxious Plants (2024). This law also provides provisions mandating the control of noxious weeds on private property.

Regulated categories – detailed explanation MDA Noxious Weed List (2025) :

• FN – Federal noxious weed (USDA–APHIS) – all aquatic plants listed as federal noxious weeds (except Ipomoea aquatica) are also listed as prohibited invasive species by the MDNR
• SN – State noxious weed (MDA): prevent their spread by prohibiting the importation, sale, and transportation of their propagating parts in the state. These include Specially Regulated Plants that may be sold with conditions.
• RN – Restricted noxious weed (MDA): prevent their spread by prohibiting the importation, sale, and transportation of their propagating parts in the state
• PS – State prohibited weed seed (MDA)
• RS – State restricted weed seed (MDA)

The prohibited invasive plant species regulated under the Invasive species statutes (6216.0100 – 6216.0600) are aquatic at this time. All aquatic plants listed as federal noxious weeds (except Ipomoea aquatica) are also listed as prohibited invasive species by the MDNR.

For explanation of laws and current list of Minnesota prohibited and restricted noxious weeds see MDA Noxious Weed List opens in a new browser tab.  Minnesota Statutes 18.75 – 18.91 opens in a new browser tab and 160.23 opens in a new browser tab.

What is regulated

🌱 Regulated noxious-weed seed taxa

• Prohibited weed seed: Palmer amaranth (Amaranthus palmeri), hemp* (Cannabis sativa), plumeless thistle (Carduus acanthoides), musk thistle (Carduus nutans), Canada thistle (Cirsium arvense), bull thistle (Cirsium vulgare), field bindweed (Convolvulus arvensis), leafy spurge (Euphorbia esula), perennial peppergrass (Lepidium draba), Russian knapweed (Rhaponticum repens), and perennial sowthistle (Sonchus arvensis).
• Restricted weed seed: quackgrass (Agropyron repens), hoary alyssum (Berteroa incana), dodder (Cuscuta spp.), buckhorn plantain (Plantago lanceolata), wild radish (Raphanus raphanistrum), giant foxtail (Setaria faberi), wild mustard (Sinapis arvensis), horsenettle (Solanum carolinense), eastern black nightshade (Solanum ptycanthum), and field pennycress or Frenchweed*** (Thlaspi arvense).

🌱 Regulated Invasive plants and noxious-weeds, MDA Noxious Weed List

• 💧Prohibited aquatic invasive plants: mosquito fern or water velvet (Azolla pinnata), flowering rush (Butomus umbellatus), Mediterranean strain killer algae (Caulerpa taxifolia), Australian stonecrop (Crassula helmsii), anchored or rooted water hyacinth (Eichhornia azurea), hydrilla (Hydrilla verticillata), European frog-bit (Hydrocharis morsus-ranae), Indian swampweed or Miramar weed (Hygrophila polysperma), water-spinach or swamp morning-glory (Ipomoea aquatica), African oxygen weed (Lagarosiphon major), ambulia (Limnophila sessiliflora), purple loosestrife (Lythrum salicaria, Lythrum virgatum, including any variety, hybrid, or cultivar), broadleaf paperbark tree (Melaleuca quinquenervia), heart-shaped false pickerelweed (Monochoria hastata), arrowleaf false pickerelweed (Monochoria vaginalis), Eurasian watermilfoil (Myriophyllum spicatum), brittle naiad (Najas minor), starry stonewort (Nitellopsis obtusa), yellow floating heart (Nymphoides peltata), ducklettuce (Ottelia alismoides), common reed, non-native subspecies (Phragmites australis subsp. australis), curly-leaf pondweed (Potamogeton crispus), arrowhead (Sagittaria sagittifolia), Salvinia species including aquarium watermoss and giant salvinia (Salvinia auriculata, S. biloba, S. herzogii, S. molesta), wetland nightshade (Solanum tampicense), exotic bur-reed (Sparganium erectum), water aloe or water soldiers (Stratiotes aloides), and water chestnut (Trapa natans).
• Prohibited / Eradicate terrestrial plants: Palmer amaranth (Amaranthus palmeri), tree of heaven (Ailanthus altissima), black swallow-wort (Cynanchum louiseae), pale swallow-wort (Cynanchum rossicum), brown knapweed (Centaurea jacea), diffuse knapweed (Centaurea diffusa), yellow starthistle (Centaurea solstitialis), Grecian foxglove (Digitalis lanata), common teasel (Dipsacus fullonum), cutleaf teasel (Dipsacus laciniatus), giant hogweed (Heracleum mantegazzianum), hooked hair hops (formerly Japanese hops) (Humulus japonicus), Dalmatian toadflax (Linaria dalmatica), golden honeysuckle vine (formerly Japanese honeysuckle) (Lonicera japonica), stiltgrass (Microstegium vimineum), Johnsongrass (Sorghum halepense), and red hailstone (Thladiantha dubia).
• Prohibited / Control terrestrial plants: Common barberry (Berberis vulgaris), narrowleaf bittercress (Cardamine impatiens), plumeless thistle (Carduus acanthoides), round leaf bittersweet (Celastrus orbiculatus), meadow knapweed (Centaurea × moncktonii), spotted knapweed (Centaurea stoebe subsp. micranthos), Canada thistle (Cirsium arvense), poison hemlock (Conium maculatum), leafy spurge (Euphorbia virgata and Euphorbia esula), purple loosestrife (Lythrum salicaria), wild parsnip (Pastinaca sativa, except for non-wild cultivated varieties), non-native phragmites (Phragmites australis subsp. australis), Bohemian knotweed (Polygonum × bohemicum), Japanese knotweed (Polygonum cuspidatum), giant knotweed (Polygonum sachalinense), and common tansy (Tanacetum vulgare).
• Restricted terrestrial plants: European alder (Alnus glutinosa), garlic mustard (Alliaria petiolata), creeping meadow foxtail (Alopecurus arundinaceus), porcelain berry (Ampelopsis brevipedunculata), Japanese barberry (restricted cultivars only) (Berberis thunbergii), Siberian peashrub (Caragana arborescens; exemption for Green Spires® ‘Jefarb’), wild carrot or Queen Anne’s lace (Daucus carota), autumn olive (Elaeagnus umbellata), winged burning bush (Euonymus alatus), lesser celandine (Ficaria verna), glossy buckthorn (Frangula alnus), Amur honeysuckle (Lonicera maackii), Bell’s honeysuckle (Lonicera × bella), Morrow’s honeysuckle (Lonicera morrowii), Tatarian honeysuckle (Lonicera tatarica), creeping miscanthus (formerly Amur silvergrass) (Miscanthus sacchariflorus), common or European buckthorn (Rhamnus cathartica), black locust (Robinia pseudoacacia), multiflora rose (Rosa multiflora), crown vetch (Securigera varia), and saltcedar (Tamarix ramosissima).
• Specially regulated terrestrial plants: Amur maple (Acer ginnala), Norway maple, including all cultivars (Acer platanoides), Tatarian maple (Acer tataricum), common butterbur (Petasites hybridus), giant butterbur (Petasites japonicus), Amur corktree (Phellodendron amurense), Callery pear (Pyrus calleryana), rowan or mountain ash (Sorbus aucuparia), and poison ivy (Toxicodendron radicans and T. rydbergii).

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Montana MO

Regulatory Overview

Montana ensures the quality of seed through Montana Code Agricultural Seed and Patented Plant Material (80-5-1 – 80-5-6), Noxious Weed Seed Free Forage Act (MCA 80-7-9) and associated Seed Labelling Rules (4.12.30 – 4.12.3115). This prevents the spread of some invasive plants, but does not target plants in the horticultural trades.

Invasive plants and noxious weeds are regulated under Montana Disease, Pest, and Weed Control (80-7-701- 80-7-720); Weed and Pest Control (7-22-21 & – 7-22-41) and associated Designation of Noxious Weeds (4.2.201 – 4.2.210) . These regulations grant authority to the Montana Department of Agriculture for the listing of noxious weeds and specifying the modes of prevention or reduction required. This includes the ability to prohibit of sales.

There is an additional Aquatic Invasive Species Law (80-7-1001-80-7-1031) and associated rule (12.5.706) aimed at preventing the introduction, importation, and infestation of species like Eurasian watermilfoil (Myriophyllum spicatum) (Montana Fish Wildlife an d Parks, AIS Rules).

What is regulated

🌱 Regulated noxious-weed seed taxa – Labeling for agricultural, vegetable, and flower seed must show the name and approximate number of restricted noxious-weed seeds per pound.

• Jointed goatgrass (Aegilops cylindrica), quackgrass (Agropyron repens), Palmer amaranth (Amaranthus palmeri), wild oat (Avena fatua), dodder (Cuscuta spp.), Persian darnel (Lolium persicum), curly dock (Rumex crispus), perennial sowthistle (Sonchus arvensis).

🌱 Regulated noxious-weed taxa. These categories specify required control measures. PRIORITY 3 plants specifically prohibit sales.

• PRIORITY 1A:) These weeds require eradication: Yellow starthistle (Centaurea solstitialis)ˌ Dyer’s woad (Isatis tinctoria), common reed (Phragmites australis ssp. australis).
• PRIORITY 1B: These weeds require eradication or containment and education: rush skeletonweed (Chondrilla juncea); Scotch broom (Cytisus scoparius); purple loosestrife (Lythrum salicaria); knotweed complex (Polygonum cuspidatumˌ P. sachalinenseˌ P. × bohemicumˌ Fallopia japonicaˌ F. sachalinensisˌ F. × bohemicaˌ Reynoutria japonicaˌ R. sachalinensisˌ and R.× bohemica)
• PRIORITY 2A: These weeds require eradication or containment where less abundant: flowering rush (Butomus umbellatus); blueweed (Echium vulgare); Meadow hawkweed complex (Hieracium caespitosumˌ H. praealtumˌ H. floridundumˌ and Pilosella caespitosa); orange hawkweed (Hieracium aurantiacumˌ Pilosella aurantiaca); Yellowflag iris (Iris pseudacorus); perennial pepperweed (Lepidium latifolium); Eurasian watermilfoil (Myriophyllum spicatum); tall buttercup (Ranunculus acris); tansy ragwort (Senecio jacobaeaˌ Jacobaea vulgaris)
• PRIORITY 2B: These weeds require control where less abundant. Management shall be prioritized by local weed districts: Russian knapweed (Acroptilon repensˌ Rhaponticum repens); hoary alyssum (Berteroa incana); Canada thistle (Cirsium arvense); leafy spurge (Euphorbia esula); whitetop (Cardaria drabaˌ Lepidium draba); diffuse knapweed (Centaurea diffusa); spotted knapweed (Centaurea stoebe, C. maculosa); oxeye daisy (Chrysanthemum vulgare, Leucanthemum vulgare); field bindweed (Convolvulus arvensis); St. Johnswort (Hypericum perforatum); Dalmatian toadflax (Linaria dalmatica); sulfur cinquefoil (Potentilla recta); houndstongue (Cynoglossum officinale); yellow toadflax (Linaria vulgaris); curlyleaf pondweed (Potamogeton crispus); saltcedar (Tamarix spp.); common tansy (Tanacetum vulgare).
• PRIORITY 3 REGULATED PLANTS (NOT MONTANA LISTED NOXIOUS WEEDS) These regulated plants have the potential to have significant negative impacts. The plant may not be intentionally spread or sold other than as a contaminant in agricultural products. The state recommends research, education, and prevention to minimize the spread of the regulated plant: cheatgrass (Bromus tectorum); Brazilian waterweed (Egeria densa); Russian olive (Elaeagnus angustifolia); hydrilla (Hydrilla verticillata); parrot feather watermilfoil (Myriophyllum aquaticum or M. brasiliense).

💧Aquatic invasive plants included in the above list.

• flowering rush (Butomus umbellatus); rush skeletonweed (Chondrilla juncea); Scotch broom (Cytisus scoparius); Brazilian waterweed (Egeria densa); hydrilla (Hydrilla verticillata); yellowflag iris (Iris pseudacorus); purple loosestrife (Lythrum salicaria); parrot feather watermilfoil (Myriophyllum aquaticum or M. brasiliense); Eurasian watermilfoil (Myriophyllum spicatum); common reed (Phragmites australis ssp. australis); knotweed complex (Polygonum cuspidatum, P. sachalinense, P. × bohemicum, Fallopia japonica, F. sachalinensis, F. × bohemica, Reynoutria japonica, R. sachalinensis, and R. × bohemica); curlyleaf pondweed (Potamogeton crispus); saltcedar (Tamarix spp.).

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New Hampshire NH

Regulatory Overview

The New Hampsphire Seed Law (433:1) and associated Seed Administrative Rule (Agr. 2200) provide for the regulation of the labeling, sale, offering, or transporting for sale of agricultural, vegetable, flower, tree, and shrub seeds in the state. They are implemented by the NH Department of Agriculture, Markets & Food (DAMF).

The DAMF also oversees regulation of invasive species within the plant industry under an Insect, Pests and Plant Diseases Statute (430:51-58). This enables the state to make it illegal to collect, transport, buy, sell, or release any listed invasive plants. Regulated plants are specified under the rules for Invasive Species code (Ag. 3800).

Aquatic invasive plants are regulated under Water Management and Protection for the Control of marine pollution and aquatic growth (487-16a-b, 18, 24). No exotic aquatic weeds shall be offered for sale, transported, or introduced in the state without a permit. Regulated aquatic weeds are designated in associated rules for Water Quality (Env-Wq 1300). This is overseen by NH Department of Environmental Services (NHDES) .

In 2023, N(NHDAMF) NHDES jointly published a New Hampshire Comprehensive Invasive Plant List.

What is regulated

🌱  Noxious-weed seed taxa regulated under the NH Seed Law

• Prohibited weed seeds: quackgrass (Agropyron repens); Canada thistle (Cirsium arvense); field bindweed (Convolvulus arvensis); serrated bedstraw (Galium spp.); tussock (Nasella trichotoma).
• Restricted weed seeds: corncockle (Agrostemma githago); wild onion (Allium canadense); wild garlic (Allium vineale); yellow rocket (Barbarea vulgaris); wild mustard (Brassica spp.); nutsedge (nutgrass) (Cyperus esculentus); dodder (Cuscuta spp.); purple loosestrife (Lythrum salicaria); ribwort plantain (Plantago lanceolata); annual bluegrass (Poa annua); wild radish (Raphanus raphanistrum); horsenettle (Solanum carolinense); perennial sowthistle (Sonchus arvensis).
• Undesirable grass seed: redtop (Agrostis gigantea); bentgrass (creeping, colonial, velvet) (Agrostis spp.); bermudagrass (Cynodon spp.); orchardgrass (Dactylis glomerata); tall fescue (Festuca arundinacea); meadow fescue (Festuca pratensis); velvetgrass (Holcus lanatus); timothy (Phleum pratense); annual bluegrass (Poa annua); rough bluegrass (Poa trivialis).

🌱  Invasive plant taxa prohibited under Invasive Plants Species Rules 3800

• Norway maple (Acer platanoides; incl. Acer platanoides var. schwedleri); European black alder (Alnus glutinosa; syn. Alnus alnus, Betula alnus var. glutinosa); tree of heaven (Ailanthus altissima; syn. Ailanthus glandulosa); garlic mustard (Alliaria petiolata; syn. Alliaria alliaria, Alliaria officinalis, Erysimum alliaria, Sisymbrium alliaria); Japanese barberry (Berberis thunbergii); European barberry (Berberis vulgaris); oriental bittersweet (Celastrus orbiculatus); spotted knapweed (Centaurea stoebe subsp. micranthos; syn. Centaurea biebersteinii, C. maculosa misapplied); black swallow-wort (Cynanchum louiseae; syn. Cynanchum nigrum, Vincetoxicum nigrum); pale swallow-wort (Cynanchum rossicum; syn. Vincetoxicum rossicum); autumn olive (Elaeagnus umbellata var. parvifolia; syn. Elaeagnus parvifolia); burning bush (Euonymus alatus; syn. Celastrus alatus); glossy buckthorn (Frangula alnus; syn. Rhamnus frangula); reed sweet grass (Glyceria maxima; syn. Glyceria spectabilis, Molinia maxima); giant hogweed (Heracleum mantegazzianum); dame’s rocket (Hesperis matronalis); ornamental jewelweed (Impatiens glandulifera; syn. Impatiens roylei); water-flag (Iris pseudacorus); perennial pepperweed (Lepidium latifolium; syn. Cardaria latifolia); blunt-leaved privet (Ligustrum obtusifolium; incl. var. leiocalyx); common privet (Ligustrum vulgare); Japanese honeysuckle (Lonicera japonica; syn. Nintooa japonica); Amur honeysuckle (Lonicera maackii); Morrow’s honeysuckle (Lonicera morrowii); Tartarian honeysuckle (Lonicera tatarica); Bella honeysuckle (Lonicera ×bella); moneywort (Lysimachia nummularia); Japanese stilt grass (Microstegium vimineum; syn. Andropogon vimineum, Eulalia viminea); mile-a-minute weed (Persicaria perfoliata; syn. Ampelygonum perfoliatum, Polygonum perfoliatum); kudzu (Pueraria montana var. lobata; syn. Pueraria lobata, Pueraria thunbergiana, Dolichos lobatus); Japanese knotweed (Reynoutria japonica var. japonica; syn. Fallopia japonica, Polygonum cuspidatum); giant knotweed (Reynoutria sachalinensis; syn. Fallopia sachalinensis, Polygonum sachalinense); Bohemian knotweed (Reynoutria ×bohemica; syn. Fallopia ×bohemica); common buckthorn (Rhamnus cathartica); multiflora rose (Rosa multiflora).

💧 Aquatic invasive taxa prohibited under Prohibited Exotic Aquatic Weeds Env-Wq 1303.02

• Flowering rush (Butomus umbellatus); fanworts (Cabomba spp., incl. Cabomba caroliniana); swamp stonecrop (Crassula helmsii); Brazilian elodea (Egeria densa); great willowherb / hairy willowherb (Epilobium hirsutum); reed sweet grass / manna grass (Glyceria maxima); hydrilla / anacharis (Hydrilla verticillata); frogbit (Hydrocharis morsus-ranae); East Indian hygrophila (Hygrophila polysperma); water spinach (Ipomoea aquatica); yellow iris / yellow flag iris (Iris pseudacorus); African oxygen weed (Lagarosiphon major); ambulia (Limnophila sessiliflora); purple loosestrife (Lythrum salicaria, L. virgatum, L. alatum and cultivars); water fern (Marsilea quadrifolia); water forget-me-not (Myosotis scorpioides); milfoils / featherfoils (Myriophyllum spp., incl. M. heterophyllum, M. spicatum, M. aquaticum); European naiad (Najas minor); yellow floating heart (Nymphoides peltata); common reed (Phragmites australis [syn. P. communis]); curly leaf pondweed (Potamogeton crispus); double flowering arrowhead / Japanese arrowhead / old world arrowhead (Sagittaria japonica); giant sagittaria (Sagittaria sagittifolia); giant salvinia (Salvinia molesta); water chestnuts (Trapa spp.); slender cattail (Typha gracilis); dwarf cattail / Laxman’s cattail (Typha laxmannii); miniature cattail / micro-mini cattail (Typha minima).

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New York NY

Regulatory Overview

The New York Consolidated Laws (AGM Chapter 69, §§ 136–142) establish the Inspection and Sale of Seeds law, including the statutory definition of Noxious Weed Seeds and authority to regulate them (1 NYCRR Part 95).

In 2015, 6 NYCRR Part 575 Prohibited and Regulated Invasive Species became effective (March 10, 2015) under the New York State Department of Environmental Conservation, establishing prohibitions and regulations on possession, transport, sale, importation, purchase, and introduction of select invasive species. Regulated species require labels that clearly state: Invasive Species – Harmful to the Environment.

A companion regulation, 6 NYCRR Part 576 Aquatic Invasive Species Spread Prevention, was later adopted to require reasonable precautions to prevent spreading aquatic invasive species via watercraft and related equipment.

New York State licensing laws for nurseries require adherence to invasive species regulations.

In addition, weeds, including invasive plants, may require control under the New York State Property Maintenance Code  (PMCNYS 2025 – §§ 202 & 302.4). But weeds here is broadly defined as Uncultivated vegetation such as grasses, brush, briars, and annual plants, excluding trees and cultivated vegetation, such as shrubs, flowers, gardens, and vegetation used for agricultural purposes. 

🌱 2 noxious weed-seed taxa – Noxious Weed Seeds

• spurge, leafy (Euphorbia esula)
• bluegrass, annual (Poa annua) (in lawn seed)

🌱 69 Noxious weeds taxa Prohibited and Regulated Invasive Species 

• sycamore maple (Acer pseudoplatanus); japanese chaff flower (Achyranthes japonica); garlic mustard (Alliaria petiolata); porcelain berry (Ampelopsis brevipedunculata); wild chervil (Anthriscus sylvestris); japanese angelica tree (Aralia elata); mugwort (Artemisia vulgaris); small carpet grass (Arthraxon hispidus); japanese barberry (Berberis thunbergii); slender false brome (Brachypodium sylvaticum); fanwort (Cabomba caroliniana); narrowleaf bittercress (Cardamine impatiens); oriental bittersweet (Celastrus orbiculatus); spotted knapweed (Centaurea stoebe syn. C. biebersteinii, C. diffusa, C. maculosa misapplied, C. ×psammogena); canada thistle (Cirsium arvense syn. C. setosum, C. incanum, Serratula arvensis); black swallow-wort (Cynanchum louiseae syn. C. nigrum, Vincetoxicum nigrum); pale swallow-wort (Cynanchum rossicum syn. C. medium, Vincetoxicum medium, V. rossicum); chinese yam (Dioscorea polystachya syn. D. batatas); cut-leaf teasel (Dipsacus laciniatus); brazilian waterweed (Egeria densa); autumn olive (Elaeagnus umbellata); cypress spurge (Euphorbia cyparissias); leafy spurge (Euphorbia esula); lesser celandine (Ficaria verna syn. Ranunculus ficaria); smooth buckthorn (Frangula alnus syn. Rhamnus frangula); reed manna grass (Glyceria maxima); giant hogweed (Heracleum mantegazzianum); japanese hops (Humulus japonicus); hydrilla, water thyme (Hydrilla verticillata); european frogbit (Hydrocharis morsus-ranae); cogon grass (Imperata cylindrica syn. I. arundinacea, Lagurus cylindricus); yellow iris (Iris pseudacorus); broad-leaved pepper-grass (Lepidium latifolium); chinese lespedeza (Lespedeza cuneata); border privet (Ligustrum obtusifolium); japanese honeysuckle (Lonicera japonica); amur honeysuckle (Lonicera maackii); morrow’s honeysuckle (Lonicera morrowii); tartarian honeysuckle (Lonicera tatarica); fly honeysuckle (Lonicera × bella); uruguayan primrose-willow (Ludwigia hexapetala syn. L. grandiflora); floating primrose-willow (Ludwigia peploides); garden loosestrife (Lysimachia vulgaris); purple loosestrife (Lythrum salicaria); japanese stilt grass (Microstegium vimineum); marsh dewflower (Murdannia keisak); parrot-feather (Myriophyllum aquaticum); broadleaf water-milfoil (Myriophyllum heterophyllum); broadleaf water-milfoil hybrid (Myriophyllum heterophyllum × M. laxum); eurasian water-milfoil (Myriophyllum spicatum); yellow floating heart (Nymphoides peltata); wavyleaf basketgrass (Oplismenus hirtellus); mile-a-minute weed (Persicaria perfoliata syn. Polygonum perfoliatum); amur cork tree (Phellodendron amurense); common reed grass (Phragmites australis); golden bamboo (Phyllostachys aurea); yellow groove bamboo (Phyllostachys aureosulcata); curly pondweed (Potamogeton crispus); kudzu (Pueraria montana); japanese knotweed (Reynoutria japonica syn. Fallopia japonica, Polygonum cuspidatum); giant knotweed (Reynoutria sachalinensis syn. Fallopia sachalinensis, Polygonum sachalinensis); bohemian knotweed (Reynoutria × bohemica syn. Fallopia × bohemica, Polygonum × bohemica); common buckthorn (Rhamnus cathartica); multiflora rose (Rosa multiflora); wineberry (Rubus phoenicolasius); gray florist’s willow (Salix atrocinerea); cup-plant (Silphium perfoliatum); water chestnut (Trapa natans); beach vitex (Vitex rotundifolia).
• Regulated plants that require labelling: Norway maple (Acer platanoides); Japanese virgin’s bower (Clematis terniflora); burning bush (Euonymus alatus); winter creeper (Euonymus fortunei)*; Chinese silver grass (Miscanthus sinensis)*; black locust (Robinia pseudoacacia).
• Exempt cultivars include Berberis thunbergii (‘Aurea’, ‘UCONNBTCP4N’ [Crimson Cutie™], PPAF; ‘UCONNBTB113’ [Lemon Cutie™], PPAF; ‘UCONNBTB048’ [Lemon Glow™], PPAF; ‘UCONNBTB039’ [Mr. Green Genes™], PP 30,128 P3); Miscanthus sinensis (‘My Fair Maiden’, ‘Scout’); and Euonymus fortunei (‘Kewensis’, ‘Vanilla Frosting’). These exemptions apply only to the specifically named cultivars and do not apply to the species as a whole; exemptions are conditional and subject to review should new evidence indicate increased invasive risk.

💧 aquatic and wetland invasive taxa included in Prohibited and Regulated Invasive Species 

• 💧 wetland species included in the above list: smooth buckthorn (Frangula alnus syn. Rhamnus frangula); reed manna grass (Glyceria maxima); yellow iris (Iris pseudacorus); purple loosestrife (Lythrum salicaria); marsh dewflower (Murdannia keisak); common reed grass (Phragmites australis).
• 💧 aquatic species included in the above list: fanwort (Cabomba caroliniana); brazilian waterweed (Egeria densa); hydrilla (Hydrilla verticillata); european frogbit (Hydrocharis morsus-ranae); uruguayan primrose-willow (Ludwigia hexapetala syn. L. grandiflora); floating primrose-willow (Ludwigia peploides); parrot-feather (Myriophyllum aquaticum); broadleaf water-milfoil hybrid (Myriophyllum heterophyllum × M. laxum); eurasian water-milfoil (Myriophyllum spicatum); yellow floating heart (Nymphoides peltata); curly pondweed (Potamogeton crispus); water chestnut (Trapa natans).

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North Dakota ND

Regulatory Overview

North Dakota regulates seed quality through its state seed laws, which establish standards for purity, labeling, and allowable levels of prohibited and restricted weed seeds in agricultural and forage seed sold in the state. These requirements are set out in NDCC Chapter 4.1-53 (Seeds) and implemented through administrative rules and seed certification programs. Specific lists of prohibited and restricted weed seeds are designated by the State Seed Commissioner through administrative rule and can be found in N. D. Administrative Code § 74-03-01-09, Field Inspection. This provision identifies prohibited noxious weed seeds subject to zero tolerance and restricted noxious weed seeds subject to limitation and labeling. These designations underpin seed inspection, certification, and enforcement and are reflected in the USDA’s State Noxious-Weed Seed Requirements used for Federal Seed Act compliance.

Under North Dakota law, every person is required to “do all things necessary and proper to control the spread of noxious weeds.” This includes preventing seed dispersal and eradicating infestations in accordance with § 4.1-47-01 through § 4.1-47-28 of the North Dakota Century Code, as summarized in the North Dakota Department of Agriculture’s 2025 Noxious Weeds Law and Regulations. No person may distribute, sell, or offer for sale within this state a noxious weed.

The North Dakota Game and Fish Department, with input from members of the Aquatic Invasive Species Committee (AISC), has created a listing of North Dakota aquatic nuisance species (ND ANS).

In North Dakota, aquatic nuisance species are addressed through a pathway-based management frameworkadministered by the North Dakota Game and Fish Department. Under its statutory authority and with input from the Aquatic Invasive Species Committee (AISC), the Department maintains a list of North Dakota aquatic nuisance species and implements measures to reduce their spread. As outlined in North Dakota Administrative Code Chapter 30-01-01, these measures focus on education, monitoring, and inspections, particularly related to watercraft, equipment, and water use activities. This framework emphasizes prevention of spread rather than regulation of plant sales or comprehensive ecosystem-based invasive species control.

🌱 noxious weed-seed taxa

• Prohibited: absinthe wormwood (Artemisia absinthium); Palmer amaranth (Amaranthus palmeri) – zero tolerance applied; musk thistle (Carduus nutans); Canada thistle (Cirsium arvense); field bindweed (Convolvulus arvensis); diffuse knapweed (Centaurea diffusa); spotted knapweed (Centaurea stoebe subsp. micranthos); yellow starthistle (Centaurea solstitialis) – zero tolerance applied; hound’s-tongue (Cynoglossum officinale); leafy spurge (Euphorbia esula); Dalmatian toadflax (Linaria genistifolia subsp. dalmatica); yellow toadflax (Linaria vulgaris); hoary cress (Lepidium chalepense); purple loosestrife (Lythrum salicaria); purple loosestrife, cultivars (Lythrum virgatum and all cultivars); Russian knapweed (Rhaponticum repens); perennial sowthistle (Sonchus arvensis); saltcedar (Tamarix spp.).
• Restricted: wild oat (Avena fatua); hedge bindweed (Calystegia sepium); dodder (Cuscuta spp., except Cuscuta coryli); quackgrass (Elymus repens subsp. repens).

🌱 Noxious weed taxa Noxious Weeds Law and Regulations

• absinth wormwood (Artemisia absinthium L.); Palmer amaranth (Amaranthus palmeri); musk thistle (Carduus nutans L.); diffuse knapweed (Centaurea diffusa Lam.); Russian knapweed (Centaurea repens L.); spotted knapweed (Centaurea maculosa Lam.); Canada thistle (Cirsium arvense (L.) Scop.); hound’s-tongue (Cynoglossum officinale L.); leafy spurge (Euphorbia esula L.); Dalmatian toadflax (Linaria genistifolia subsp. dalmatica); yellow toadflax (Linaria vulgaris); purple loosestrife (Lythrum salicaria L., Lythrum virgatum L., and all cultivars); saltcedar (Tamarix spp.).

💧 Aquatic invasive taxa regulated as aquatic nuisance species

• didymo or rock snot (Didymosphenia geminata); Eurasian watermilfoil (Myriophyllum spicatum); curly-leaf pondweed (Potamogeton crispus).

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Ohio OH

Regulatory Overview

In Ohio, plant regulation is divided into three distinct but overlapping legal frameworks, each designed to address a different pathway of spread and type of impact.

Under the authority of the Ohio Department of Agriculture, invasive plant species are regulated through the Ohio Revised Code (ORC 901.50) and Ohio Administrative Code (OAC 901:5-30-01 – Note: Ohio appears to be blocking Canadian IPs from accessing their websites). These are defined as non-native plants that cause or are likely to cause economic, environmental, or human health harm, based on scientific evidence. This category is primarily a trade-focused tool, prohibiting the sale, propagation, distribution, and importation of listed species in order to prevent new introductions through the horticultural pathway.

In contrast, noxious weeds are regulated under a separate set of statutes spanning ORC Chapter 5579, with the designated list of prohibited noxious weeds maintained in OAC 901:5-37-01. These provisions impose a land management obligation: landowners and public authorities are required to control or destroy listed noxious weeds, with enforcement occurring at the municipal, township, or county level. This framework does not restrict sale but instead addresses the impacts of plants once they are established in the landscape, particularly in agricultural and roadside contexts.

A third and often overlooked category is noxious weed seeds, regulated under Ohio’s Seed Law (ORC Chapter 907; OAC 901:5-27-06). This framework governs seeds in commerce and distinguishes between prohibited noxious weed seeds, which must be absent from seed lots, and restricted noxious weed seeds, which may be present only at very low levels and must be disclosed on seed labels.

Together, these three systems — trade prohibition, landowner control, and seed purity — reflect historically separate regulatory approaches that do not always align. As a result, some species may still be legally sold even if they are recognized as harmful and subject to control once established, highlighting a broader policy gap that continues to challenge invasive plant management.

🌱 Noxious weed-seed taxa

• Prohibited noxious weed seeds (OAC 901:5-27-06(A)): Russian knapweed (Acroptilon repens), Palmer amaranth (Amaranthus palmeri), waterhemp (Amaranthus tuberculatus), kochia (Bassia scoparia), hedge bindweed (Calystegia sepium), musk thistle (Carduus nutans), Canada thistle (Cirsium arvense), field bindweed (Convolvulus arvensis), quackgrass (Elytrigia repens), leafy spurge (Euphorbia esula), giant hogweed (Heracleum mantegazzianum), hairy whitetop (Lepidium appelianum), heart-podded hoary cress (Lepidium draba sub. draba), purple loosestrife (Lythrum salicaria), serrated tussock (Nassella trichotoma), apple of Peru (Nicandra physalodes), perennial sowthistle (Sonchus arvensis), shattercane (Sorghum bicolor), Johnsongrass (Sorghum halepense), and Columbus grass (Sorghum × almum).
• Restricted noxious weed seeds (OAC 901:5-27-06(B)): corncockle (Agrostemma githago), wild onion (Allium canadense), wild garlic (Allium vineale), wild mustard (Brassica arvensis & Brassica kaber), poison hemlock (Conium maculatum), dodder (Cuscuta spp.), oxeye daisy (Leucanthemum vulgare), buckhorn (Plantago lanceolata), curly dock (Rumex crispus), and horsenettle (Solanum carolinense).

A note on taxonomy: the legal text used “Palmer Amarantha” rather than Palmer amaranth, and “Sorghum halpense” rather than halepense.

🌱 Noxious weed taxa

• Prohibited: Palmer amaranth (Amaranthus palmeri), waterhemp (Amaranthus tuberculatus), forage kochia (Bassia prostrata), kochia (Bassia scoparia), hedge bindweed (Calystegia sepium), musk thistle (Carduus nutans), spotted knapweed (Centaurea stoebe), Canada thistle (Cirsium arvense), poison hemlock (Conium maculatum), field bindweed (Convolvulus arvensis), marestail (Conyza canadensis), cypress spurge (Euphorbia cyparissias), giant hogweed (Heracleum mantegazzianum), hairy whitetop or ballcress (Lepidium appelianum), heart-podded hoary cress (Lepidium draba sub. draba), purple loosestrife (Lythrum salicaria), serrated tussock (Nassella trichotoma), apple of Peru (Nicandra physalodes), wild parsnip (Pastinaca sativa), mile-a-minute weed (Persicaria perfoliata), yellow groove bamboo (Phyllostachys aureasculata), kudzu (Pueraria montana var. lobata), Japanese knotweed (Reynoutria japonica), Russian knapweed (Rhaponticum repens), Russian thistle (Salsola tragus), cressleaf groundsel (Senecio glabellus), perennial sowthistle (Sonchus arvensis), shattercane (Sorghum bicolor), Columbus grass (Sorghum × almum), Johnsongrass (Sorghum halepense), and grapevines (Vitis spp.).
• The list of secondary noxious weeds was rescinded but wild carrot (Daucus carota), oxeye daisy (Leucanthemum vulgare), and wild mustard (Brassica spp.) are named in ORC 5579.05 as requiring control.

Two notes: The statute includes conditional qualifiers for grapevines (groups of 100+ not maintained for two consecutive years) and yellow groove bamboo (when spread from original planting and not being maintained). Also, the statute spells mile-a-minute as “Persicaria perfoliate” and yellow groove bamboo as “Phyllostachys aureasculata” — I’ve used the accepted botanical spellings (perfoliata and aureasculata respectively).

🌱 63 Invasive taxa regulated under OAC 901:5-30-01 (effective February 13, 2023) – Invasive plant species

• Tree-of-heaven (Ailanthus altissima), garlic mustard (Alliaria petiolata), porcelainberry (Ampelopsis brevipedunculata), pinnate mosquitofern (Azolla pinnata), common barberry (Berberis vulgaris), flowering rush (Butomus umbellatus), Asian bittersweet (Celastrus orbiculatus), spotted knapweed (Centaurea stoebe ssp. micranthos), common teasel (Dipsacus fullonum), cutleaf teasel (Dipsacus laciniatus), Brazilian waterweed (Egeria densa), anchored water hyacinth (Eichhornia azurea), Russian olive (Elaeagnus angustifolia), autumn olive (Elaeagnus umbellata), hairy willowherb (Epilobium hirsutum), Japanese knotweed (Fallopia japonica), lesser celandine (Ficaria verna), giant hogweed (Heracleum mantegazzianum), dame’s rocket (Hesperis matronalis), hydrilla (Hydrilla verticillata), European frogbit (Hydrocharis morsus-ranae), Indian swampweed (Hygrophila polysperma), yellow flag iris (Iris pseudacorus), African oxygen weed (Lagarosiphon major), common privet (Ligustrum vulgare), Asian marshweed (Limnophila sessiliflora), Japanese honeysuckle (Lonicera japonica), Amur honeysuckle (Lonicera maackii), Morrow’s honeysuckle (Lonicera morrowii), Tatarian honeysuckle (Lonicera tatarica), purple loosestrife (Lythrum salicaria), European wand loosestrife (Lythrum virgatum), European water-clover (Marsilea quadrifolia), Japanese stiltgrass (Microstegium vimineum), arrowleaf false pickerelweed (Monochoria hastata), heartshape false pickerelweed (Monochoria vaginalis), white mulberry (Morus alba), parrot feather watermilfoil (Myriophyllum aquaticum), Eurasian watermilfoil (Myriophyllum spicatum), brittle waternymph (Najas minor), yellow floating heart (Nymphoides peltata), duck lettuce (Ottelia alismoides), princess tree (Paulownia tomentosa), mile-a-minute (Persicaria perfoliata), reed canary grass (Phalaris arundinacea), common reed (Phragmites australis ssp. australis), water lettuce (Pistia stratiotes), curly pondweed (Potamogeton crispus), kudzu (Pueraria montana var. lobata), Callery pear (Pyrus calleryana), European buckthorn (Rhamnus cathartica), multiflora rose (Rosa multiflora), arrowhead (Sagittaria sagittifolia), crack willow (Salix fragilis), common salvinia (Salvinia minima), giant salvinia (Salvinia molesta), simple bur-reed (Sparganium erectum), water soldier (Stratiotes aloides), water chestnut (Trapa natans), narrowleaf cattail (Typha angustifolia), hybrid cattail (Typha × glauca), Siberian elm (Ulmus pumila), and black swallowwort (Vincetoxicum nigrum).

A few notes on discrepancies between the rule text and accepted botanical nomenclature: the rule spells dame’s rocket as “Hesperis matronlis” and European water-clover as “Marsilea guadrifolia” — both are typographical errors in the code. I’ve used the correct spellings above. The rule states reed canary grass sold for animal feed is exempt from the trade prohibition.

💧 ~32 are aquatic or wetland taxa (this is not specified in the legislation, but is shared for educational/comparative purposes)

• Pinnate mosquitofern (Azolla pinnata); Flowering rush (Butomus umbellatus); Brazilian waterweed (Egeria densa); Anchored water hyacinth (Eichhornia azurea); Giant hogweed (Heracleum mantegazzianum); Hydrilla (Hydrilla verticillata); European frog-bit (Hydrocharis morsus-ranae); Indian swampweed (Hygrophila polysperma); Yellow flag iris (Iris pseudacorus); African oxygen weed (Lagarosiphon major); Asian marshweed (Limnophila sessiliflora); Purple loosestrife (Lythrum salicaria); European wand loosestrife (Lythrum virgatum); European water-clover (Marsilea quadrifolia); Arrowleaf false pickerelweed (Monochoria hastata); Heartshape false pickerelweed (Monochoria vaginalis); Parrot feather watermilfoil (Myriophyllum aquaticum); Eurasian watermilfoil (Myriophyllum spicatum); Brittle waternymph (Najas minor); Yellow floating heart (Nymphoides peltata); Duck lettuce (Ottelia alismoides); Common reed (Phragmites australis subsp. australis); Water lettuce (Pistia stratiotes); Curly-leaved pondweed (Potamogeton crispus); Arrowhead (Sagittaria sagittifolia); Common salvinia (Salvinia minima); Giant salvinia (Salvinia molesta); Simple bur-reed (Sparganium erectum); Water soldier (Stratiotes aloides); Water chestnut (Trapa natans); Narrowleaf cattail (Typha angustifolia); Hybrid cattail (Typha × glauca)

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Pennsylvania PA

Regulatory Overview

In Pennsylvania, plant regulation operates through three distinct but partially integrated legal frameworks — noxious weed control, seed purity, and invasive plant management — each addressing a different pathway of spread and type of impact. Pennsylvanias noxious weed framework includes invasive plants.

The centrepiece of Pennsylvania’s regulatory system is the Controlled Plant and Noxious Weed Act (3 Pa.C.S. Chapter 15, Act 46 of 2017), administered by the Pennsylvania Department of Agriculture (PDA). This law consolidates both trade restrictions and land management obligations within a single tiered framework. Noxious weeds are classified into three categories based on distribution and feasibility of control: Class A species are geographically limited and targeted for eradication; Class B species are widely established and managed for suppression; and Class C species are not known to occur in the state but pose a risk if introduced, and include by default all species on the Federal Noxious Weed List. The Act prohibits the sale, propagation, transport, distribution, and other handling of all listed noxious weeds and controlled plants without a permit from PDA, though the management response — eradication, containment, or prevention — varies by classification. PDA may issue control orders requiring landowners to treat noxious weeds, and municipalities that carry out treatment on a noncomplying landowner’s property may recover costs. Oversight is provided by the Controlled Plant and Noxious Weed Committee, a statutory administrative board with representation from six state agencies, legislative agriculture committees, and three appointed stakeholder seats representing agriculture, the ornamental and horticultural industry, and higher education. The Committee may add or remove species by majority vote following public notice and meeting. The Act also established a cultivar exemption process: sterile cultivars of listed noxious weeds may be approved for continued sale through formal application to PDA. To date, four Japanese barberry cultivars (the WorryFree® Series) and one glossy buckthorn cultivar (Fine Line®) have been approved.

A second framework governs noxious weed seeds under Pennsylvania’s Seed Act (3 Pa.C.S. Chapter 71) and associated regulations (7 Pa. Code Chapter 111). As in many jurisdictions, this system distinguishes between prohibited noxious weed seeds, which must be absent from seed lots (zero tolerance), and restricted noxious weed seeds, which may be present only at specified low levels and must be declared on seed labels by name and number per pound. Notably, the 2017 Act created a mandatory statutory bridge between the two systems: when the Controlled Plant and Noxious Weed Committee designates a new noxious weed, it shall also determine, in consultation with PDA, whether the species’ seed falls within the category of a prohibited or restricted noxious weed seed, and those seeds shall then be regulated under 7 Pa. Code Ch. 111. While the seed regulations still require their own amendment process, this integration is more deliberate than what exists in many states where noxious weed and seed purity frameworks operate entirely independently.

A third, non-regulatory layer is administered by the Pennsylvania Department of Conservation and Natural Resources (DCNR), which maintains a science-based invasive plant list used to guide management on state forest and park lands. DCNR invasive species are ranked by severity of ecological threat: Rank 1 (Severe Threat) for species that spread easily into native plant communities and displace native vegetation; Rank 2 (Significant Threat) for species that are invasive but less aggressively so; Rank 3 (Lesser Threat) for species that spread mainly in or near disturbed areas; and a Watch List for species that are severe problems in surrounding states but not yet widely reported in Pennsylvania. Despite Pennsylvania’s relatively integrated statutory framework, a significant gap remains between ecological risk assessment and regulatory control. Many species identified by DCNR as severe ecological threats remain legally available in commerce.

🌱 Noxious weed-seed taxa

• Prohibited: bindweed, field (Convolvulus arvensis), bindweed, hedge (Calystegia sepium), quackgrass (Elytrigia repens), Canada thistle (Cirsium arvense), multiflora rose (Rosa multiflora), johnsongrass (Sorghum halepense), shattercane (Sorghum bicolor), marijuana (Cannabis sativa), mile-a-minute (Polygonum perfoliatum), kudzu-vine (Pueraria lobata), purple Loosestrife and cultivars (Lythrum salicaria), giant Hogweed (Heracleum mantegazzianum), goatsrue (Galega officinalis), jimsonweed (Datura stramonium).
• Restricted: bedstraw (Galium spp .), buckhorn plantain (Plantago lanceolata), corncockle (Agrostemma githago), dodder (Cuscuta spp.) horsenettle (Solanum carolinense), perennial sow thistle (Sonchus arvensis), wild garlic (Allium vineale), wild onion (Allium canadense), wild mustard (Brassica juncea, B. kaber, and B. nigra), bull thistle (Cirsium vulgare), musk thistle (Carduus nutans).
• Restricted in turf grass seed: bermudagrass. (Cynodon spp.), annual bluegrass. (Poa annua), rough bluegrass. (Poa trivialis), bentgrass (creeping, colonial, velvet), (Agrostis spp .), meadow fescue (Festuca pratensis), tall fescue (Festuca arundinaceae), orchardgrass (Dactylis glomerata), timothy (Phleum pratense), velvetgrass (Holcus lanatus), redtop (Agrostis gigantea).

🌱 Noxious-weeds in addition to the Federal NW list Class C.

• Class A noxious weeds: Palmer amaranth (Amaranthus palmeri S. Watson), water hemp (Amaranthus rudis), tall water hemp (Amaranthus tuberculatus), animated oat (Avena sterilis L.), dodder (Cuscuta spp., except for native species), goats rue (Galega officinalis L.), giant hogweed (Heracleum mantegazzianum Sommier & Levier), hydrilla (Hydrilla verticillata (L.f.) Royle), wavyleaf basketgrass (Oplismenus hirtellus (L.) P. Beauv. subsp. undulatifolius), broom rape (Orobanche spp., except for native species), kudzu (Pueraria lobata (Willd.) Ohwi).
• Class B noxious weeds: musk thistle (Carduus nutans L.), Canada thistle (Cirsium arvense L. ), bull thistle (Cirsium vulgare L. ), purple loosestrife (Lythrum salicaria L., Lythrum virgatum L., Lythrum complex, cultivars and any combination thereof), mile-a-minute (Persicaria perfoliata (L.) syn. Polygonum perfoliatum L.), multiflora rose (Rosa multiflora L.), shatter cane (Sorghum bicolor L. Moench), Johnson grass (Sorghum halepense (L.) Pers.), poison hemlock (Conium maculatum L.)
• Class C noxious weeds are any Federal noxious weeds listed in 7 CFR 360.200 (relating to designation of noxious weeds) not established in this Commonwealth which are not referenced above.

💧 Aquatic and wetland regulated taxa

• giant hogweed (Heracleum mantegazzianum Sommier & Levier), hydrilla (Hydrilla verticillata (L.f.) Royle), purple loosestrife (Lythrum salicaria L., Lythrum virgatum L., Lythrum complex, cultivars and any combination thereof),

🌱 DNCR Invasive Plants – Not A Regulatory List
Rank 1 – Severe Threat

• Tree-of-heaven (Ailanthus altissima); Garlic mustard (Alliaria petiolata); Japanese angelica tree (Aralia elata); Porcelain berry (Ampelopsis glandulosa); Japanese barberry (Berberis thunbergii); European barberry (Berberis vulgaris); Oriental bittersweet (Celastrus orbiculatus); Poison hemlock (Conium maculatum); Japanese knotweed (Fallopia japonica); Giant knotweed (Fallopia sachalinensis); Hybrid knotweed (Fallopia × bohemica); Lesser celandine (Ficaria verna); Glossy buckthorn (Frangula alnus); Goatsrue (Galega officinalis); Giant hogweed (Heracleum mantegazzianum); Hydrilla (Hydrilla verticillata); Japanese hops (Humulus japonicus); Japanese honeysuckle (Lonicera japonica); Amur honeysuckle (Lonicera maackii); Morrow’s honeysuckle (Lonicera morrowii); Beautiful honeysuckle (Lonicera morrowii × bella); Standish honeysuckle (Lonicera standishii); Tartarian honeysuckle (Lonicera tatarica); Sweet breath honeysuckle (Lonicera fragrantissima); Purple loosestrife (Lythrum salicaria); Japanese stiltgrass (Microstegium vimineum); Wavyleaf basketgrass (Oplismenus hirtellus); Mile-a-minute (Persicaria perfoliata); Common reed (Phragmites australis subsp. australis); Kudzu (Pueraria montana var. lobata); Common buckthorn (Rhamnus cathartica); Multiflora rose (Rosa multiflora); Japanese spiraea (Spiraea japonica); Shattercane (Sorghum bicolor subsp. × drummondii); European water chestnut (Trapa natans); Narrowleaf cattail (Typha angustifolia); Hybrid cattail (Typha × glauca); Black swallowwort (Vincetoxicum nigrum); Pale swallowwort (Vincetoxicum rossicum); Parrot feather watermilfoil (Myriophyllum aquaticum); Eurasian watermilfoil (Myriophyllum spicatum); Curly pondweed (Potamogeton crispus).

Rank 2 – Significant Threat

• Norway maple (Acer platanoides); Mimosa (Albizia julibrissin); European black alder (Alnus glutinosa); Small carpetgrass (Arthraxon hispidus); Butterfly bush (Buddleja davidii); Brown knapweed (Centaurea jacea); Black knapweed (Centaurea nigra); Spotted knapweed (Centaurea stoebe); Greater celandine (Chelidonium majus); Canada thistle (Cirsium arvense); Bull thistle (Cirsium vulgare); Russian olive (Elaeagnus angustifolia); Autumn olive (Elaeagnus umbellata); Winged euonymus (Euonymus alatus); Wintercreeper (Euonymus fortunei); Dame’s rocket (Hesperis matronalis); Yellow flag iris (Iris pseudacorus); Chinese bushclover (Lespedeza cuneata); Shrubby bushclover (Lespedeza bicolor); Japanese privet (Ligustrum japonicum); Border privet (Ligustrum obtusifolium); Chinese privet (Ligustrum sinense); Common privet (Ligustrum vulgare); Chinese wisteria (Wisteria sinensis); Japanese wisteria (Wisteria floribunda); Empress tree (Paulownia tomentosa); Amur corktree (Phellodendron amurense); Japanese corktree (Phellodendron japonicum); Lavella corktree (Phellodendron lavallei); Reed canary grass (Phalaris arundinacea); Golden bamboo (Phyllostachys aurea); Yellow groove bamboo (Phyllostachys aureosulcata); Giant timber bamboo (Phyllostachys bambusoides); Rough bluegrass (Poa trivialis); Callery pear (Pyrus calleryana); Crown-vetch (Securigera varia); Bee-bee tree (Tetradium daniellii); Linden viburnum (Viburnum dilatatum); Doublefile viburnum (Viburnum plicatum); Siebold viburnum (Viburnum sieboldii).

Rank 3 – Lesser Threat

• Goutweed (Aegopodium podagraria); Wild chervil (Anthriscus sylvestris); Mugwort (Artemisia vulgaris); Flowering rush (Butomus umbellatus); Narrowleaf bittercress (Cardamine impatiens); Spiny plumeless thistle (Carduus acanthoides); Musk thistle (Carduus nutans); Jimsonweed (Datura stramonium); Common teasel (Dipsacus fullonum); Cutleaf teasel (Dipsacus laciniatus); Hairy willowherb (Epilobium hirsutum); Smallflower hairy willowherb (Epilobium parviflorum); English ivy (Hedera helix); Orange day-lily (Hemerocallis fulva); Velvetgrass (Holcus lanatus); Moneywort (Lysimachia nummularia); Chinese silvergrass (Miscanthus sinensis); White mulberry (Morus alba); Japanese pachysandra (Pachysandra terminalis); Reed canary grass (Phalaris arundinacea); Bristled knotweed (Persicaria longiseta); Paper mulberry (Broussonetia papyrifera); Tall fescue (Schedonorus arundinaceus); Common chickweed (Stellaria media); Bigleaf periwinkle (Vinca major); Common periwinkle (Vinca minor); Brazilian waterweed (Egeria densa); Brittle waternymph (Najas minor); Starry stonewort (Nitellopsis obtusa); Carolina fanwort (Cabomba caroliniana); Guelder rose (Viburnum opulus).

Watch List

• Amur maple (Acer ginnala); Japanese maple (Acer palmatum); Chocolate vine (Akebia quinata); Giant reed (Arundo donax); Japanese clematis (Clematis terniflora); Chinese yam (Dioscorea polystacha); Cogon grass (Imperata cylindrica); Golden rain-tree (Koelreuteria paniculata); Large flower primrose willow (Ludwigia grandiflora subsp. hexapetala); Yellow floating heart (Nymphoides peltata); Sawtooth oak (Quercus acutissima); Common frogbit (Hydrocharis morsus-ranae); Ravenna grass (Tripidium ravennae); Siberian elm (Ulmus pumila); Johnson grass (Sorghum halepense); Palmer amaranth (Amaranthus palmeri)

💧 14 Aquatic invasive taxa identified by Pennsylvania DNRC (only hydrilla is regulated)

• Carolina fanwort (Cabomba caroliniana), Brazilian waterweed (Egeria densa), hydrilla (Hydrilla verticillata), common frogbit (Hydrocharis morsus-ranae), large flower primrose willow (Ludwigia grandiflora ssp. hexapetala), parrot feather (Myriophyllum aquaticum), watermilfoil (Myriophyllum spicatum), brittle waternymph (Najas minor), starry stonewort (Nitellopsis obtusa), yellow floatingheart (Nymphoides peltata), curly pondweed (Potamogeton crispus), European water chestnut (Trapa natans), narrow-leaved cattail (Typha angustifolia), hybrid cattail (Typha x glauca)

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Vermont VT

Regulatory Overview

In Vermont, invasive plant regulation operates through multiple distinct but loosely connected legal frameworks administered primarily by the Vermont Agency of Agriculture, Food and Markets (VAAFM) and the Vermont Agency of Natural Resources (VANR). VAAFM is responsible for seed regulation, noxious weed designation, and plant pest authority, while VANR regulates invasive plants along shorelines and aquatic plant movement under environmental protection statutes.

Seed Quality (6 V.S.A. Chapter 35; CVR 20-031-019): As in other jurisdictions, Vermont regulates the quality of seed sold through seed purity laws. Noxious weed seed are seeds considered “objectionable in agricultural crops, lawns and gardens.” Origin or ecological impact are not noted. The most difficult to control are “Prohibited” and must be entirely absent from seed lots (zero tolerance). Restricted noxious weed seeds may be present at low levels but must be declared on labels. There is no statutory linkage between the noxious weed seeds listed in the Seed Standards and the Noxious Weed regulation.

Noxious Weed Regulation (Quarantine #3 – CVR 20-031-021): Vermont’s primary invasive plant control mechanism is the Quarantine #3 – Noxious Weeds rule, adopted in 2002 and most recently amended in 2012. Noxious weeds are broadly defined as any non-native plant whose presence is detrimental to the environment, crops or other desirable plants, livestock, land, or other property, or is injurious to the public health or the economy generally. The word “invasive” appears only once in the quarantine rule (in the cultivar exemption provision) and is not defined.

Species are classified based on their presence in the state at the time of listing. Class A NWs are not known to occur in Vermont on the date of listing. Movement, sale, possession, cultivation, and distribution is prohibited. Class B NWs are limited distribution statewide. While the sale, movement, and distribution remain prohibited, possession and cultivation of established plantings is permitted. The regulation includes 39 named species (11 Class A, 28 Class B) plus all species on the Federal Noxious Weed List (7 C.F.R. § 360.200), incorporated by reference. 

And advisory panel, Vermont Invasive Exotic Plant Advisory Committee (VIEPAC) reviews noxious plant lists annually and recommends additions and deletions. However, the regulation itself has not been updated since 2012. The Secretary of VAAFM has been able to use the Pest Survey, Detection, and Management statute (6 V.S.A. Chapter 84, § 1030) to regulate additional plants. In 2024, eight plant species were designated “plant pests.” While sales are not prohibited, they do require a permit. The use of the term plant pests to designate invasive plants is consistent with IPPC recommendations (2017), though it creates some confusion for the general public.

Environmental Regulations (ANR – 10 V.S.A. § 1442; 10 V.S.A. § 1454): In addition to noxious weeds and plant pests specified by the VAAFM, nuisance plants are mentioned in Lake Shoreland Protection Standards (10 V.S.A. § 1442). These standards prohibit noxious weeds and nuisance plants (like poison ivy and poison oak) along waterfronts.  Additional regulations prohibit the transport of any aquatic plant, aquatic plant part, or aquatic nuisance species to or from any Vermont water 10 V.S.A. §1454).

The VANR posts a non-regulatory Invasive Plant Watch List (2017). It identifies species that are recommended to be avoided and may be added to the quarantine list at a later date, but it carries no legal authority. 

🌱 Noxious weed-seed taxa

• Prohibited (zero tolerance): field bindweed (Convolvulus arvensis), quackgrass (Elymus repens), Canada thistle (Cirsium arvense), bedstraw (Galium spp.), serrated tussock (Nassella trichotoma), velvetleaf (Abutilon theophrasti)
• Restricted: dodder (Cuscuta spp.), horsenettle (Solanum carolinense), wild mustard (Brassica spp.), wild onion (Alliumspp.), wild radish (Raphanus raphanistrum), perennial sowthistle (Sonchus arvensis), purple loosestrife (Lythrum salicaria), corncockle (Agrostemma githago).

🌱 Noxious weeds — Quarantine #3

• Class A : fanwort (Cabomba caroliniana), Brazilian elodea (Egeria densa), hydrilla (Hydrilla verticillata), East Indian hygrophila (Hygrophila polysperma), parrot feather (Myriophyllum aquaticum), variable-leaved milfoil (Myriophyllum heterophyllum), giant salvinia (Salvinia auriculata, S. biloba, S. herzogii, S. molesta), pale swallow-wort (Vincetoxicum hirundinaria, syn. Cynanchum rossicum).
• Class B: goutweed (Aegopodium podagraria), tree-of-heaven (Ailanthus altissima), garlic mustard (Alliaria petiolata), flowering rush (Butomus umbellatus), oriental bittersweet (Celastrus orbiculatus), Japanese knotweed (Fallopia japonica, syn. Polygonum cuspidatum), common frogbit (Hydrocharis morsus-ranae), bell honeysuckle (Lonicera × bella), Japanese honeysuckle (Lonicera japonica), Amur honeysuckle (Lonicera maackii), Morrow’s honeysuckle (Lonicera morrowii), Tartarian honeysuckle (Lonicera tatarica), purple loosestrife (Lythrum salicaria), Eurasian watermilfoil (Myriophyllum spicatum), yellow floating heart (Nymphoides peltata), common reed (Phragmites australis subsp. australis), curly-leaf pondweed (Potamogeton crispus), common buckthorn (Rhamnus cathartica), glossy buckthorn (Rhamnus frangula, syn. Frangula alnus), European water chestnut (Trapa natans), black swallow-wort (Vincetoxicum nigrum, syn. Cynanchum louiseae), Norway maple (Acer platanoides), common barberry (Berberis vulgaris), Japanese barberry (Berberis thunbergii), burning bush (Euonymus alatus), yellow flag iris (Iris pseudacorus), Amur maple (Acer ginnala), European naiad (Najas minor).
• All weeds listed in 7 C.F.R. 360.200 (Federal Noxious Weed List) as amended are also incorporated by reference as Class B.
• Cultivar exemptions: Frangula alnus ‘Asplenifolia’ and Frangula alnus ‘Fine Line’ are exempt from the quarantine.

🌱 Plant Pest Designations (May 2024) – Designated under 6 V.S.A., Chapter 84

• kudzu (Pueraria montana var. lobata), mile-a-minute (Persicaria perfoliata), Japanese stiltgrass (Microstegium vimineum), porcelain berry (Ampelopsis glandulosa), wineberry (Rubus phoenicolasius), waterwheel (Aldrovanda vesiculosa), water hyacinth (Eichhornia crassipes), water soldier (Stratiotes aloides).

💧 Aquatic and wetland regulated taxa

• The following aquatic and wetland species are regulated under the Noxious Weed Quarantine: fanwort (Cabomba caroliniana), Brazilian elodea (Egeria densa), hydrilla (Hydrilla verticillata), East Indian hygrophila (Hygrophila polysperma), parrot feather (Myriophyllum aquaticum), variable-leaved milfoil (Myriophyllum heterophyllum), giant salvinia (Salvinia auriculata, S. biloba, S. herzogii, S. molesta), Eurasian watermilfoil (Myriophyllum spicatum), common frogbit (Hydrocharis morsus-ranae), yellow floating heart (Nymphoides peltata), curly-leaf pondweed (Potamogeton crispus), European water chestnut (Trapa natans), flowering rush (Butomus umbellatus), European naiad (Najas minor), common reed (Phragmites australis subsp. australis), purple loosestrife (Lythrum salicaria).
• Additional aquatic species are regulated under the 2024 Plant Pest Designations: waterwheel (Aldrovanda vesiculosa), water hyacinth (Eichhornia crassipes), water soldier (Stratiotes aloides).
• Additionally, 10 V.S.A. § 1454 broadly prohibits the transport of any aquatic plant, aquatic plant part, or aquatic nuisance species to or from Vermont waters, regardless of whether the species is specifically listed under either the quarantine or the plant pest designations.

🌱 Watch List — Not a Regulatory List (November 2017)

Waterwheel (Aldrovanda vesiculosa) [subsequently designated plant pest 2024], European black alder (Alnus glutinosa), false indigo (Amorpha fruticosa), porcelain berry (Ampelopsis brevipedunculata) [subsequently designated plant pest 2024], wild chervil (Anthriscus sylvestris), pond water-starwort (Callitriche stagnalis), narrowleaf bittercress (Cardamine impatiens), spotted knapweed (Centaurea maculosa), water hyacinth (Eichhornia crassipes) [subsequently designated plant pest 2024], Russian olive (Elaeagnus angustifolia), autumn olive (Elaeagnus umbellata), European spindle-tree (Euonymus europaeus), cypress spurge (Euphorbia cyparissias), meadow dropwort (Filipendula ulmaria), reed mannagrass (Glyceria maxima), dame’s rocket (Hesperis matronalis), Japanese hops (Humulus japonicus), Himalayan balsam (Impatiens glandulifera), border privet (Ligustrum obtusifolium), dwarf honeysuckle (Lonicera xylosteum), garden loosestrife (Lysimachia vulgaris), European waterclover (Marsilea quadrifolia), Japanese stiltgrass (Microstegium vimineum) [subsequently designated plant pest 2024], wall-lettuce (Mycelis muralis), starry stonewort (Nitellopsis obtusa), wild parsnip (Pastinaca sativa), princess tree (Paulownia tomentosa), butterbur sweet-coltsfoot (Petasites hybridus), Japanese sweet-coltsfoot (Petasites japonicus), reed canary grass (Phalaris arundinacea), mile-a-minute (Polygonum perfoliatum) [subsequently designated plant pest 2024], giant knotweed (Polygonum sachalinense, syn. Fallopia sachalinensis), white poplar (Populus alba), black locust (Robinia pseudoacacia), watercress (Rorippa nasturtium-aquaticum), multiflora rose (Rosa multiflora), false spiraea (Sorbaria sorbifolia), water soldier (Stratiotes aloides) [subsequently designated plant pest 2024], common valerian (Valeriana officinalis).

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Washington WA

Regulatory Overview

Washington State regulates harmful plants through a three-part system that combines seed controls, trade restrictions, and land management. State laws in the Revised Code of Washington (RCW) set out the framework to ensure seed quality and consumer protection and the framework to limit economic loss and adverse effects to Washington’s agricultural, natural, and human resources caused by noxious weeds. The lists of regulated plants are specified within Washington Administrative Code (WAC) and may be updated annually. These regulations come under the oversight of the Washington Department of Agriculture.

The Seed Law and General Rules for Seed Regulations (RCW 15.49; WAC 16-301) define noxious weed seeds in commercial seed lots to protect consumers.  Prohibited (primary) noxious weed seeds, which are defined as “highly destructive, competitive, and/or difficult to control,” must be entirely absent from seed for sale. Restricted (secondary) noxious weed seeds, which are “objectionable in fields, lawns, and gardens of this state, but which can be controlled by cultural or chemical practices,” may be present only at levels declared on the label. Plant origin is not specified. 

The Noxious Weed Law and State Noxious Weed List  (RCW 17.10; WAC 16-750) lay out the requirements for establishing lists and managing Class A, B, or C noxious weeds. Class A species are rare and must be eradicated. Class B species are subject to region-specific control designations, allowing prevention efforts to focus on areas where they are limited or absent. Class C species are generally widespread, with control determined at the county level. Implementation is largely carried out by County Weed Boards making enforcement dependent on local capacity and priorities. Learn more about Washington Noxious Weed Laws.

Invasive plants are further regulated under Noxious Weed Seed and Plant Quarantine (WAC 16-751). “It is illegal to transport, buy, sell, or trade any quarantined species. It is also illegal to distribute seed packets, flower seed blends, or ‘wildflower mixes’ that include these plants. Anyone who violates the quarantine restrictions is subject to a civil penalty of up to $5,000 per violation.” The list of non-native terrestrial and aquatic species is updated anually (WAC 16-752-610). The State Noxious Weed List and the Quarantine list overlap substantially but are not identical.

🌱 Noxious-weed seed for seed quality purposes (WAC 16-301-045; WAC 16-301-050)

• Prohibited (Primary) Noxious Weed Seeds — must be entirely absent from seed for sale: velvetleaf (Abutilon theophrasti), jointed goatgrass (Aegilops cylindrica, only in small grain), camelthorn (Alhagi maurorum), Palmer’s amaranth (Amaranthus palmeri), bladder campion (Silene vulgaris, only in timothy Phleum pratense), hedge bindweed (Calystegia sepium), purple starthistle (Centaurea calcitrapa), diffuse knapweed (Centaurea diffusa), brown knapweed (Centaurea jacea), bighead knapweed (Centaurea macrocephala), meadow knapweed (Centaurea × moncktonii), black knapweed (Centaurea nigra), Vochin knapweed (Centaurea nigrescens), yellow starthistle (Centaurea solstitialis), spotted knapweed (Centaurea stoebe subsp. australis), rush skeletonweed (Chondrilla juncea), Canada thistle (Cirsium arvense), field bindweed (Convolvulus arvensis), quackgrass (Elymus repens), leafy spurge (Euphorbia esula), tansy ragwort (Jacobaea vulgaris), hoary cress (Lepidium draba), hairy whitetop (Lepidium appelianum), perennial pepperweed (Lepidium latifolium), lepyrodiclis (Lepyrodiclis holosteoides), serrated tussock (Nassella trichotoma), Russian knapweed (Rhaponticum repens), Austrian fieldcress (Rorippa austriaca), white cockle (Silene latifolia, only in timothy Phleum pratense), silverleaf nightshade (Solanum elaeagnifolium), perennial sowthistle (Sonchus arvensis), perennial sorghum, including but not limited to Johnsongrass, sorghum almum, and perennial sweet sudangrass (Sorghum spp.).
• Restricted (Secondary) Noxious Weed Seeds — may be present only at levels declared on the label: blackgrass (Alopecurus myosuroides), Western ragweed (Ambrosia psilostachya), wild oat (Avena fatua), black mustard (Brassica nigra), gromwell (Buglossoides arvensis, only in small grain), field sandbur (Cenchrus spinifex), dodder (Cuscuta spp.), halogeton (Halogeton glomeratus), common St. Johnswort (Hypericum perforatum), dyer’s woad (Isatis tinctoria), blue lettuce (Lactuca tatarica subsp. pulchella), Dalmatian toadflax (Linaria dalmatica), yellow toadflax (Linaria vulgaris), Iva axillaris (Iva axillaris), plantains (Plantago spp.), wild radish (Raphanus raphanistrum), docks and sorrel (Rumexspp.), wild mustard (Sinapis arvensis subsp. arvensis), medusahead (Taeniatherum caput-medusae), field pennycress (Thlaspi arvense), puncturevine (Tribulus terrestris).
• Note: The prohibited list uses Centaurea × moncktonii for meadow knapweed, while the noxious weed list uses Centaurea × gerstlaueri — both names have been applied to this hybrid complex. Similarly, the prohibited list uses Euphorbia esula for leafy spurge while the noxious weed list uses Euphorbia virgata — another case where the accepted taxonomy has shifted but the regulatory text retains the older name.

🌱 Noxious-weed seed taxa from Chapter 16-750 WAC STATE NOXIOUS WEED LIST AND SCHEDULE OF MONETARY PENALTIES Last Update: 12/1/25 (Class A WAC 16-750-005; Class B WAC 16-750-011; Class C WAC 16-750-015) [plants in BOLD are also on the Quarantine Plant list below and are prohibited from sale]

• Class A: garlic mustard (Alliaria petiolata), Palmer amaranth (Amaranthus palmeri), false brome (Brachypodium sylvaticum), flowering rush (Butomus umbellatus), Turkish thistle (Carduus cinereus), Italian thistle (Carduus pycnocephalus), slenderflower thistle (Carduus tenuiflorus), round leaf bittersweet (Celastrus orbiculatus), purple starthistle (Centaurea calcitrapa), bighead knapweed (Centaurea macrocephala), Vochin knapweed (Centaurea nigrescens), marsh thistle (Cirsium palustre), oriental clematis (Clematis orientalis), common crupina (Crupina vulgaris), eggleaf spurge (Euphorbia oblongata), goatsrue (Galega officinalis), French broom (Genista monspessulana), reed sweetgrass (Glyceria maxima), Texas blueweed (Helianthus ciliaris), giant hogweed (Heracleum mantegazzianum), hydrilla (Hydrilla verticillata), small-flowered jewelweed (Impatiens parviflora), dyer’s woad (Isatis tinctoria), South American spongeplant (Limnobium laevigatum), floating primrose-willow (Ludwigia peploides), wild four-o’clock (Mirabilis nyctaginea), variable-leaf milfoil and hybrid (Myriophyllum heterophyllum and M. heterophyllum × M. hippuroides), kudzu (Pueraria montana var. lobata), Mediterranean sage (Salvia aethiopis), meadow clary (Salvia pratensis), clary sage (Salvia sclarea), ricefield bulrush (Schoenoplectus mucronatus), milk thistle (Silybum marianum), silverleaf nightshade (Solanum elaeagnifolium), Johnsongrass (Sorghum halepense), smooth cordgrass (Spartina alterniflora), common cordgrass (Spartina anglica), dense-flowered cordgrass (Spartina densiflora), saltmeadow cordgrass (Spartina patens), Spanish broom (Spartium junceum), Syrian beancaper (Zygophyllum fabago).
• Class B: velvetleaf (Abutilon theophrasti), camelthorn (Alhagi maurorum), indigobush (Amorpha fruticosa), common bugloss (Anchusa officinalis), wild chervil (Anthriscus sylvestris), kochia (Bassia scoparia), hoary alyssum (Berteroa incana), white bryony (Bryonia alba), butterfly bush (Buddleja davidii), fanwort (Cabomba caroliniana), plumeless thistle (Carduus acanthoides), musk thistle (Carduus nutans), hanging sedge (Carex pendula, C. pendula subsp. pendula, and C. pendula subsp. agastachys), diffuse knapweed (Centaurea diffusa), brown knapweed (Centaurea jacea), Malta starthistle (Centaurea melitensis), black knapweed (Centaurea nigra), yellow starthistle (Centaurea solstitialis), spotted knapweed (Centaurea stoebe), meadow knapweed (Centaurea × gerstlaueri), rough chervil (Chaerophyllum temulum), rush skeletonweed (Chondrilla juncea), wild basil (Clinopodium vulgare), poison hemlock (Conium maculatum), houndstongue (Cynoglossum officinale), yellow nutsedge (Cyperus esculentus), Scotch broom (Cytisus scoparius), spurge laurel (Daphne laureola), blueweed (Echium vulgare), Brazilian elodea (Egeria densa), hairy willowherb (Epilobium hirsutum), myrtle spurge (Euphorbia myrsinites), leafy spurge (Euphorbia virgata), Bohemian knotweed (Fallopia × bohemica), Japanese knotweed (Fallopia japonica), giant knotweed (Fallopia sachalinensis), lesser celandine (Ficaria verna), common fennel (Foeniculum vulgare, except bulbing fennel F. vulgare var. azoricum), shiny geranium (Geranium lucidum), herb-Robert (Geranium robertianum), Texas blueweed (Helianthus ciliaris), giant hogweed (Heracleum mantegazzianum), orange hawkweed (Hieracium aurantiacum), meadow hawkweeds (all nonnative species and hybrids of Hieracium subgenus Pilosella), wall hawkweeds (all nonnative species and hybrids of Hieracium subgenus Hieracium), policeman’s helmet (Impatiens glandulifera), tansy ragwort (Jacobaea vulgaris), yellow archangel (Lamiastrum galeobdolon), perennial pepperweed (Lepidium latifolium), Dalmatian toadflax (Linaria dalmaticassp. dalmatica), water primrose (Ludwigia hexapetala), annual bugloss (Lycopsis arvensis), garden loosestrife (Lysimachia vulgaris), purple loosestrife (Lythrum salicaria), wand loosestrife (Lythrum virgatum), parrotfeather (Myriophyllum aquaticum), Eurasian watermilfoil (Myriophyllum spicatum), yellow floating heart (Nymphoides peltata), Scotch thistle (Onopordum acanthium), Himalayan knotweed (Persicaria wallichii), common reed, nonnative genotypes only (Phragmites australis), hawkweed oxtongue (Picris hieracioides), sulfur cinquefoil (Potentilla recta), Russian knapweed (Rhaponticum repens), grass-leaved arrowhead (Sagittaria graminea), saltcedar (Tamarix ramosissima), spurge flax (Thymelaea passerina), puncturevine (Tribulus terrestris), Ravenna grass (Tripidium ravennae), European coltsfoot (Tussilago farfara), gorse (Ulex europaeus).
• Class C: jointed goatgrass (Aegilops cylindrica), tree-of-heaven (Ailanthus altissima), blackgrass (Alopecurus myosuroides), beach grasses, European, American, and hybrid (Ammophila arenaria, A. breviligulata, and A. arenaria × A. breviligulata), absinth wormwood (Artemisia absinthium), Italian arum (Arum italicum), common barberry (Berberis vulgaris), longspine sandbur (Cenchrus longispinus), spikeweed (Centromadia pungens), Canada thistle (Cirsium arvense), bull thistle (Cirsium vulgare), old man’s beard (Clematis vitalba), field bindweed (Convolvulus arvensis), jubata grass (Cortaderia jubata), Pampas grass (Cortaderia selloana), English hawthorn (Crataegus monogyna), smoothseed alfalfa dodder (Cuscuta approximata), wild carrot, except where commercially grown (Daucus carota), common teasel (Dipsacus fullonum), Russian olive (Elaeagnus angustifolia), babysbreath (Gypsophila paniculata), English ivy, four cultivars only (Hedera helix ‘Baltica’, ‘Pittsburgh’, and ‘Star’, and H. hibernica ‘Hibernica’), common St. Johnswort (Hypericum perforatum), black henbane (Hyoscyamus niger), common catsear (Hypochaeris radicata), common holly, except where commercially grown (Ilex aquifolium), spotted jewelweed (Impatiens capensis), yellow flag iris (Iris pseudacorus), oxeye daisy (Leucanthemum vulgare), yellow toadflax (Linaria vulgaris), Eurasian watermilfoil hybrid (Myriophyllum spicatum × M. sibiricum), Japanese eelgrass (Nanozostera japonica), fragrant waterlily (Nymphaea odorata), green alkanet (Pentaglottis sempervirens), reed canarygrass (Phalaris arundinacea), curlyleaf pondweed (Potamogeton crispus), Austrian fieldcress (Rorippa austriaca), Himalayan blackberry (Rubus bifrons), evergreen blackberry (Rubus laciniatus), cereal rye (Secale cereale), common groundsel (Senecio vulgaris), white cockle (Silene latifolia), buffalobur (Solanum rostratum), lawnweed (Soliva sessilis), perennial sowthistle (Sonchus arvensis), Swainsonpea (Sphaerophysa salsula), medusahead (Taeniatherum caput-medusae), scentless mayweed (Tripleurospermum inodorum), nonnative cattail species and hybrids (Typha species), ventenata (Ventenata dubia), spiny cocklebur (Xanthium spinosum).

🌱 Noxious-weed seed and Quarantine Plants WAC 16-752-610 [Plants in bold not on Noxious Weed list above]

• velvetleaf (Abutilon theophrasti), tree-of-heaven (Ailanthus altissima), camelthorn (Alhagi maurorum), garlic mustard (Alliaria petiolata), Palmer’s amaranth (Amaranthus palmeri), indigobush (Amorpha fruticosa), common bugloss (Anchusa officinalis), wild chervil (Anthriscus sylvestris), cape pondweed (Aponogeton distachyos), Italian arum (Arum italicum), giant reed (Arundo donax, except variegated cultivars), kochia (Bassia scoparia), hoary alyssum (Berteroa incana), false brome (Brachypodium sylvaticum), butterfly bush (Buddleia davidii, except accepted sterile cultivars), flowering rush (Butomus umbellatus), fanwort (Cabomba caroliniana), plumeless thistle (Carduus acanthoides), Turkish thistle (Carduus cinereus), musk thistle (Carduus nutans), Italian thistle (Carduus pycnocephalus), slenderflower thistle (Carduus tenuiflorus), hanging sedge (Carex pendula, C. pendula subsp. pendula, and C. pendula subsp. agastachys), purple starthistle (Centaurea calcitrapa), diffuse knapweed (Centaurea diffusa), brown knapweed (Centaurea jacea), bighead knapweed (Centaurea macrocephala), black knapweed (Centaurea nigra), Vochin knapweed (Centaurea nigrescens), spotted knapweed (Centaurea stoebe), meadow knapweed (Centaurea × gerstlaueri), dwarf snapdragon (Chaenorhinum minus), rough chervil (Chaerophyllum temulum), oriental clematis (Clematis orientalis), wild basil (Clinopodium vulgare), poison hemlock (Conium maculatum), Australian swamp stonecrop (Crassula helmsii), common crupina (Crupina vulgaris), houndstongue (Cynoglossum officinale), yellow nutsedge (Cyperus esculentus), purple nutsedge (Cyperus rotundus), Scotch broom (Cytisus scoparius), spurge laurel (Daphne laureola), wild carrot (Daucus carota, except subsp. sativus), blueweed (Echium vulgare), Brazilian elodea (Egeria densa), hairy willowherb (Epilobium hirsutum), myrtle spurge (Euphorbia myrsinites), eggleaf spurge (Euphorbia oblongata), leafy spurge (Euphorbia virgata), Bohemian knotweed (Fallopia × bohemica), Japanese knotweed (Fallopia japonica), giant knotweed (Fallopia sachalinensis), lesser celandine (Ficaria verna), common fennel (Foeniculum vulgare, except bulbing fennel F. vulgarevar. azoricum), goatsrue (Galega officinalis), French broom (Genista monspessulana), shiny geranium (Geranium lucidum), herb-Robert (Geranium robertianum), mud mat (Glossostigma diandrum), reed sweetgrass (Glyceria maxima), Senegal tea plant (Gymnocoronis spilanthoides), common ivy (Hedera helix), Atlantic ivy (Hedera hibernica), Texas blueweed (Helianthus ciliaris), giant hogweed (Heracleum mantegazzianum), Venice mallow (Hibiscus trionum), nonnative hawkweeds (all nonnative Hieracium spp. and hybrids), hydrilla (Hydrilla verticillata), European frog-bit (Hydrocharis morsus-ranae), spotted touch-me-not (Impatiens capensis), policeman’s helmet (Impatiens glandulifera), small-flowered jewelweed (Impatiens parviflora), yellow flag iris (Iris pseudacorus), dyer’s woad (Isatis tinctoria), tansy ragwort (Jacobaea vulgaris), African elodea (Lagarosiphon major), yellow archangel (Lamiastrum galeobdolon), perennial pepperweed (Lepidium latifolium), oxeye daisy (Leucanthemum vulgare), South American spongeplant (Limnobium laevigatum), American spongeplant (Limnobium spongia), Dalmatian toadflax (Linaria dalmatica ssp. dalmatica), water primrose (Ludwigia hexapetala), floating primrose-willow (Ludwigia peploides), annual bugloss (Lycopsis arvensis), garden loosestrife (Lysimachia vulgaris), purple loosestrife (Lythrum salicaria), wand loosestrife (Lythrum virgatum), Australian water clover (Marsilea mutica), wild four o’clock (Mirabilis nyctaginea), marsh dew flower (Murdannia keisak), parrotfeather (Myriophyllum aquaticum), variable-leaf milfoil (Myriophyllum heterophyllum), Eurasian watermilfoil (Myriophyllum spicatum), slender-leaved naiad (Najas minor), yellow floating heart (Nymphoides peltata), Scotch thistle (Onopordum acanthium), green alkanet (Pentaglottis sempervirens), Himalayan knotweed (Persicaria wallichii), sulfur cinquefoil (Potentilla recta), unicorn-plant (Proboscidea louisianica), kudzu (Pueraria montana var. lobata), Russian knapweed (Rhaponticum repens), grass-leaved arrowhead (Sagittaria graminea), delta arrowhead (Sagittaria platyphylla), Mediterranean sage (Salvia aethiopis), meadow clary (Salvia pratensis), clary sage (Salvia sclarea), ricefield bulrush (Schoenoplectus mucronatus), milk thistle (Silybum marianum), silverleaf nightshade (Solanum elaeagnifolium), buffalobur (Solanum rostratum), lawnweed (Soliva sessilis), Johnsongrass (Sorghum halepense), smooth cordgrass (Spartina alterniflora), common cordgrass (Spartina anglica), dense-flowered cordgrass (Spartina densiflora), saltmeadow cordgrass (Spartina patens), Spanish broom (Spartium junceum), water soldier (Stratiotes aloides), saltcedar (Tamarix ramosissima), spurge flax (Thymelaea passerina), hedgeparsley (Torilis arvensis), water chestnut (Trapa natans), water caltrop (Trapa bicornus), puncturevine (Tribulus terrestris), Ravenna grass (Tripidium ravennae), European coltsfoot (Tussilago farfara), gorse (Ulex europaeus), swollen bladderwort (Utricularia inflata), Syrian beancaper (Zygophyllum fabago).

💧 aquatic invasive taxa from the quarantine list (WAC 16-752-610), the aquatic and wetland species

• cape pondweed (Aponogeton distachyos), flowering rush (Butomus umbellatus), fanwort (Cabomba caroliniana), Australian swamp stonecrop (Crassula helmsii), Brazilian elodea (Egeria densa), mud mat (Glossostigma diandrum), Senegal tea plant (Gymnocoronis spilanthoides), hydrilla (Hydrilla verticillata), European frog-bit (Hydrocharis morsus-ranae), yellow flag iris (Iris pseudacorus), African elodea (Lagarosiphon major), South American spongeplant (Limnobium laevigatum), American spongeplant (Limnobium spongia), water primrose (Ludwigia hexapetala), floating primrose-willow (Ludwigia peploides), Australian water clover (Marsilea mutica), marsh dew flower (Murdannia keisak), parrotfeather (Myriophyllum aquaticum), variable-leaf milfoil (Myriophyllum heterophyllum), Eurasian watermilfoil (Myriophyllum spicatum), slender-leaved naiad (Najas minor), yellow floating heart (Nymphoides peltata), grass-leaved arrowhead (Sagittaria graminea), delta arrowhead (Sagittaria platyphylla), ricefield bulrush (Schoenoplectus mucronatus), water soldier (Stratiotes aloides), water chestnut (Trapa natans), water caltrop (Trapa bicornus), swollen bladderwort (Utricularia inflata).
• There are also species that straddle the line — purple loosestrife (Lythrum salicaria), wand loosestrife (Lythrum virgatum), garden loosestrife (Lysimachia vulgaris), hairy willowherb (Epilobium hirsutum), and the cordgrasses (Spartina spp.) are wetland-associated …

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Wisconsin WI (still working on this)

Regulatory Overview

Wisconsin’s invasive plant regulations reflect an evolution in regulatory thinking—from agricultural commodity protection, to land management obligations, to more recent ecological and environmental frameworks. Harmful plants are managed through three distinct mechanisms operating under different agencies and authorities.

Seed quality and labeling regulation are administered by the Wisconsin Department of Agriculture, Trade and Consumer Protection under Wis. Stat. WS §§ 94.38–94.46; Wis. Admin. Code WAC ATCP 20. Prohibited noxious weed seeds are defined as seeds of species that are highly destructive and difficult to control. Restricted noxious weed seeds are defined as species that are objectionable but controllable through cultural practices or herbicides. These must be declared on the label if present.

A Wisconsin Noxious Weeds statute (Wis. Stat. § 66.0407) requires every person to destroy all noxious weeds on the land which they own, occupy or control. A “noxious weed” can be any weed designated as noxious by the department of natural resources (WDNR) or a regional weed governing body. 

More recently, Wisconsin enacted an Invasive Species Rule (WAC NR 40) and ecological regulatory framework, applying across all taxa.. This is administered by the WDNR under the authority of WS. § 23.22. This rule makes it illegal to possess, transport, transfer, or introduce certain invasive species without a permit. Species are classified as either “Prohibited” or “Restricted.” A Prohibited Invasive Species is one not yet found in the state, or found only in isolated locations, where eradication or containment may still be feasible. The DNR may require landowners to control prohibited species. A Restricted Invasive Species is already established in the state, and complete eradication is unlikely. Possession is allowed, but transport, transfer, and introduction are banned. A distinctive feature of Wisconsin’s system is the county-level split designation: some species are prohibited statewide except in listed counties where they are restricted, reflecting regional distribution patterns. The current NR 40 plant list includes 68 prohibited species, 14 prohibited/restricted (county-split) species, and 63 restricted species.

In July 2025, the WDNR initiated an update to species regulated under NR 40 based on input from the Wisconsin Invasive Species Council. That approval process is ongoing.

There is a Wis. Admin. Code entitled AQUATIC PLANTS: INTRODUCTION, MANUAL REMOVAL AND MECHANICAL CONTROL (WAC NR 109.08). This prohibits the distribution of an invasive aquatic plant designated by the department of natural resources without permission, and specifically prohibits Eurasian water milfoil, curly leaf pondweed, or purple loosestrife.

🌱 Noxious-weed seed taxa

• Prohibited: Palmer amaranth (Amaranthus palmeri), waterhemp (Amaranthus tuberculatus), field bindweed (Convolvulus arvensis), leafy spurge (Euphorbia esula), Canada thistle (Cirsium arvense), wild proso millet (Panicum miliaceum), woolly cupgrass (Eriochloa villosa), kudzu (Pueraria montana var. lobata), mile-a-minute weed (Polygonum perfoliatum), Russian knapweed (Centaurea picris), and spotted knapweed (Centaurea maculosa).
• Restricted: wild radish (Raphanus raphanistrum), buckhorn (Plantago lanceolata), white cockle (Silene alba), dodder (Cuscuta spp.), hoary alyssum (Berteroa incana), wild oat (Avena fatua), wild mustard (Sinapis arvensis), quackgrass (Agropyron repens), perennial sowthistle (Sonchus arvensis), giant ragweed (Ambrosia trifida), and velvetleaf (Abutilon theophrasti)
• The seed law uses older nomenclature in several places (for cross jurisdictional comparisons): Centaurea picris for Russian knapweed (now Rhaponticum repens), Centaurea maculosa for spotted knapweed (now Centaurea stoebe), Silene alba for white cockle (now Silene latifolia), and Agropyron repens for quackgrass (now Elymus repens).

🌱 Noxious-weeds (Wis. Stat. § 66.0407)

•  Canada thistle, leafy spurge, field bindweed

🌱 Invasive plant taxa from (WAC NR 40)

• Prohibited: (statewide, except where county-listed as restricted): Japanese chaff flower (Achyranthes japonica), fiveleaf akebia (Akebia quinata), porcelain berry Ampelopsis brevipedunculata, including variegated cultivar), wild chervil (Anthriscus sylvestris, except in 33 listed counties), giant reed (Arundo donax), mosquito fern (Azolla pinnata), common barberry (Berberis vulgaris), hill mustard (Bunias orientalis, except in 6 listed counties), fanwort (Cabomba caroliniana), narrow leaf bittercress (Cardamine impatiens), Asian loeseneri bittersweet (Celastrus loeseneri), diffuse knapweed (Centaurea diffusa), Russian knapweed (Centaurea repens), yellow star thistle (Centaurea solstitialis), European marsh thistle (Cirsium palustre, except in 21 listed counties), poison hemlock (Conium maculatum, except in 22 listed counties), Australian swamp crop (Crassula helmsii), Scotch broom (Cytisus scoparius), Grecian foxglove (Digitalis lanata), Chinese yam (Dioscorea batatas), Indian yam (Dioscorea oppositifolia), Brazilian waterweed (Egeria densa), anchored water hyacinth (Eichhornia azurea), floating water hyacinth (Eichhornia crassipes), hairy willowherb (Epilobium hirsutum, except in 6 listed counties), Bohemian knotweed (Fallopia × bohemica), giant knotweed (Fallopia sachalinensis), mudmat (Glossostigma cleistanthum), tall mannagrass (Glyceria maxima, except in 22 listed counties), giant hogweed (Heracleum mantegazzianum), Japanese hops (Humulus japonicus, except in 15 listed counties), hydrilla (Hydrilla verticillata), European frogbit (Hydrocharis morsus-ranae), floating marsh pennywort (Hydrocotyle ranunculoides), Indian swampweed (Hygrophila polysperma), policeman’s helmet (Impatiens glandulifera), water spinach (Ipomoea aquatica), African elodea (Lagarosiphon major), perennial pepperweed (Lepidium latifolium), sericea lespedeza (Lespedeza cuneata), lyme grass (Leymus arenarius, except in 8 listed counties), Asian marshweed (Limnophila sessiliflora), Dalmatian toadflax (Linaria dalmatica, except in Juneau and Bayfield counties), Japanese honeysuckle (Lonicera japonica), Amur honeysuckle (Lonicera maackii, except in 37 listed counties), wanded loosestrife (Lythrum virgatum), Japanese stilt grass (Microstegium vimineum), parrot feather (Myriophyllum aquaticum), brittle naiad (Najas minor), sacred lotus (Nelumbo nucifera), yellow floating heart (Nymphoides peltata), Java waterdropwort (Oenanthe javanica), wavy leaf basket grass (Oplismenus hirtellus ssp. undulatifolius), ducklettuce (Ottelia alismoides), princess tree (Paulownia tomentosa), butterfly dock (Petasites hybridus), Amur cork tree (Phellodendron amurense, except male cultivars and seedling rootstock), common reed nonnative ecotype (Phragmites australis, except in 34 listed counties), water lettuce (Pistia stratiotes), mile-a-minute vine (Polygonum perfoliatum), kudzu (Pueraria montana), sawtooth oak (Quercus acutissima), lesser celandine (Ranunculus ficaria), Himalayan blackberry (Rubus armeniacus), wineberry (Rubus phoenicolasius), Hawaii arrowhead (Sagittaria sagittifolia), giant salvinia (Salvinia herzogii), giant salvinia (Salvinia molesta), seaside goldenrod (Solidago sempervirens, except in 3 listed counties), Johnsongrass (Sorghum halepense), water soldiers (Stratiotes aloides), medusahead (Taeniatherum caput-medusae), spreading hedgeparsley (Torilis arvensis), Japanese hedgeparsley (Torilis japonica, except in 44 listed counties), water chestnut (Trapa natans), coltsfoot (Tussilago farfara), southern cattail (Typha domingensis), graceful cattail (Typha laxmannii), black swallow-wort (Vincetoxicum nigrum, except in 20 listed counties), pale swallow-wort (Vincetoxicum rossicum), Japanese wisteria (Wisteria floribunda), Chinese wisteria (Wisteria sinensis).
• Restricted (statewide, except where county-listed as prohibited): Amur maple (Acer tataricum subsp. ginnala, except all cultivars), bishop’s goutweed (Aegopodium podagraria), tree of heaven (Ailanthus altissima), garlic mustard (Alliaria petiolata), black alder (Alnus glutinosa, except all cultivars and hybrids), wild chervil (Anthriscus sylvestris, in 33 listed counties), wormwood (Artemisia absinthium), Japanese barberry (Berberis thunbergii, specific cultivars only), hill mustard (Bunias orientalis, in 6 listed counties), flowering rush (Butomus umbellatus), creeping bellflower (Campanula rapunculoides), Siberian peashrub (Caragana arborescens, except cultivars Lorbergii, Pendula, and Walkerii), plumeless thistle (Carduus acanthoides), musk thistle (Carduus nutans), oriental bittersweet (Celastrus orbiculatus), spotted knapweed (Centaurea stoebe), brown knapweed (Centaurea jacea), black knapweed (Centaurea nigra), Tyrol knapweed (Centaurea nigrescens), celandine (Chelidonium majus), Canada thistle (Cirsium arvense), European marsh thistle (Cirsium palustre, in 21 listed counties), poison hemlock (Conium maculatum, in 22 listed counties), crown vetch (Coronilla varia), hound’s tongue (Cynoglossum officinale), cut-leaved teasel (Dipsacus laciniatus), common teasel (Dipsacus fullonum), Russian olive (Elaeagnus angustifolia), autumn olive (Elaeagnus umbellata), hairy willowherb (Epilobium hirsutum, in 6 listed counties), helleborine orchid (Epipactis helleborine), burning bush (Euonymus alatus, cultivar ‘Nordine’ only), cypress spurge (Euphorbia cyparissias), leafy spurge (Euphorbia esula), Japanese knotweed (Fallopia japonica), queen of the meadow (Filipendula ulmaria), hemp nettle (Galeopsis tetrahit), white bedstraw (Galium mollugo), tall mannagrass (Glyceria maxima, in 22 listed counties), dame’s rocket (Hesperis matronalis), Japanese hops (Humulus japonicus, in 15 listed counties), Balfour’s touch-me-not (Impatiens balfourii), yellow iris (Iris pseudacorus), field scabiosa (Knautia arvensis), lyme grass (Leymus arenarius, in 8 listed counties), Dalmatian toadflax (Linaria dalmatica, in Juneau and Bayfield counties), Amur honeysuckle (Lonicera maackii, in 37 listed counties), Morrow’s honeysuckle (Lonicera morrowii), Tartarian honeysuckle (Lonicera tatarica), Bell’s honeysuckle (Lonicera × bella), moneywort (Lysimachia nummularia, except cultivar Aurea and yellow/gold leaf forms), garden yellow loosestrife (Lysimachia vulgaris), purple loosestrife (Lythrum salicaria), white mulberry (Morus alba, except male cultivars), aquatic forget-me-not (Myosotis scorpioides), woodland forget-me-not (Myosotis sylvatica), Eurasian watermilfoil (Myriophyllum spicatum), spiny naiad (Najas marina), wild parsnip (Pastinaca sativa, except garden vegetable form), ribbon grass (Phalaris arundinacea var. picta and other ornamental variegated varieties), common reed nonnative ecotype (Phragmites australis, in 34 listed counties), scarlet pimpernel (Pimpinella saxifraga), white poplar (Populus alba), curly-leaf pondweed (Potamogeton crispus), common buckthorn (Rhamnus cathartica), glossy buckthorn (Frangula alnus, including Columnaris cultivar, excluding Asplenifolia and Fineline), rose acacia (Robinia hispida), black locust (Robinia pseudoacacia, except all cultivars), multiflora rose (Rosa multiflora), seaside goldenrod (Solidago sempervirens, in 3 listed counties), tansy (Tanacetum vulgare, except cultivars Aureum and Crispum), Japanese hedgeparsley (Torilis japonica, in 44 listed counties), narrow-leaf cattail (Typha angustifolia), hybrid cattail (Typha × glauca), Siberian elm (Ulmus pumila, except hybrids and rootstock), garden heliotrope (Valeriana officinalis), black swallow-wort (Vincetoxicum nigrum, in 20 listed counties).
• Note: 14 species carry dual prohibited/restricted status depending on county
• Note: Berberis thunbergii individual named cultivars are listed.

💧 aquatic invasive taxa from WAC NR 40 and NR 109.07(2)

• mosquito fern (Azolla pinnata), flowering rush (Butomus umbellatus), fanwort (Cabomba caroliniana), Australian swamp crop (Crassula helmsii), Brazilian waterweed (Egeria densa), anchored water hyacinth (Eichhornia azurea), floating water hyacinth (Eichhornia crassipes), mudmat (Glossostigma cleistanthum), hydrilla (Hydrilla verticillata), European frogbit (Hydrocharis morsus-ranae), floating marsh pennywort (Hydrocotyle ranunculoides), Indian swampweed (Hygrophila polysperma), water spinach (Ipomoea aquatica), yellow iris (Iris pseudacorus), African elodea (Lagarosiphon major), Asian marshweed (Limnophila sessiliflora), moneywort (Lysimachia nummularia, except cultivar Aurea and yellow/gold leaf forms), garden yellow loosestrife (Lysimachia vulgaris), purple loosestrife (Lythrum salicaria), wanded loosestrife (Lythrum virgatum), aquatic forget-me-not (Myosotis scorpioides), parrot feather (Myriophyllum aquaticum), Eurasian watermilfoil (Myriophyllum spicatum), brittle naiad (Najas minor), spiny naiad (Najas marina), sacred lotus (Nelumbo nucifera), yellow floating heart (Nymphoides peltata), ducklettuce (Ottelia alismoides), water lettuce (Pistia stratiotes), curly-leaf pondweed (Potamogeton crispus), Hawaii arrowhead (Sagittaria sagittifolia), giant salvinia (Salvinia herzogii), giant salvinia (Salvinia molesta), water soldiers (Stratiotes aloides), water chestnut (Trapa natans), southern cattail (Typha domingensis), narrow-leaf cattail (Typha angustifolia), hybrid cattail (Typha × glauca), graceful cattail (Typha laxmannii).
• There are species that straddle the boundary: Glyceria maxima, Epilobium hirsutum, Phragmites australis nonnative ecotype, and Phalaris arundinacea var. picta are wetland-associated but could be categorized either way. Three of the restricted aquatic species — purple loosestrife, Eurasian watermilfoil, and curly-leaf pondweed — are also separately designated as invasive aquatic plants under NR 109.07(2)