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​Controlled Plant & Noxious Weeds

Controlled Plant List:

A controlled plant is a plant species or subspecies that has been designated by the committee as a controlled plant and is regulated to prevent uncontained growth and to negate undesirable characteristics.

  • Hemp - Cannabis sativa L and any viable part of that plant with a delta-9 THC concentration of not more than 0.3% on a dry weight basis.

PDA regulates hemp growing and processing through the Hemp Program.

About Noxious Weeds

Noxious weeds are identified as a plant that is determined to be injurious to public health, crops, livestock, agricultural land or other property and cannot be sold, transported, planted, or otherwise propagated in Pennsylvania.

Weeds are placed within one of three classes, Class A, B, or C based on spread and eradication potential and includes the Federal Noxious Weed list by default as Class C weeds.    

Class A Noxious Weed-

        • Is established in Pennsylvania
        • Is geographically limited
        • Is intended to be eradicated

Class B Noxious Weed-

        • Is widely established in Pennsylvania
        • Cannot feasibly be eradicated

Class C Noxious Weed-

        • Is not known to exist in Pennsylvania
        • Poses a potential threat if introduced into the Commonwealth
        • Is listed on the Federal Noxious Weed List


Noxious Weeds List:

Class A Noxious Weeds

    • Giant Hogweed - Heracleum mantegazzianum (Active Field Program)
    • Goatsrue - Galega officinalis (Active Field Program)
    • Kudzu - Pueraria lobata 
    • Palmer amaranth - Amaranthus palmeri
    • Waterhemp - Amaranthus rudis
    • Tall waterhemp - Amaranthus tuberculatus
    • Animated oat - Avena sterilis
    • Dodder - Cuscuta spp. (Except for native species)
    • Hydrilla - Hydrilla verticillata 
    • Broomrape - Orobanche spp. (Except for native species)
    • Wavyleaf basketgrass - Oplismenus hirtellus
    • European frogbit - Hydrocharis morsus-ranae
    • European water chestnut - Trapa natans
    • Water primrose - Ludwigia grandiflora ssp. hexapetala
    • Brazilian waterweed - Egeria densa 
    • Yellow floating heart - Nymphoides peltata
    • Ravenna Grass - Tripidium ravennae [Synonym: Saccharum ravennae] [Synonym: Erianthus ravennae
    • Wild Chervil - Anthriscus sylvestris
    • Chocolate vine - Akebia quinata
    • Japanese privet - Ligustrum japonicum (Grace period until January 10, 2025)
    • Parrot feather - Myriophyllum aquaticum 
    • Starry Stonewort - Nitellopsis obtusa

Class B Noxious Weeds

    • Bull thistle or Spear thistle - Cirsium vulgare
    • Canada Thistle - Cirsium arvense
    • Musk Thistle or Nodding Thistle - Carduus nutans
    • Johnson Grass - Sorghum halepense
    • Mile-a-Minute - Persicaria perfoliata
    • Multiflora Rose - Rosa multiflora
    • Purple Loosestrife - Exotic Lythrum species, including Lythrum salicaria L. (commonly known as purple loosestrife), the Lythrum salicaria complex and Lythrum virgatum L. (commonly known as European wand loosestrife), their cultivars and any combination thereof.
    • Shattercane - Sorghum bicolor
    • Poison hemlock - Conium maculatum
    • Tree-of-heaven - Ailanthus altissima 
    • Wild parsnip - Pastinaca sativa (except for non-wild cultivated varieties) 
    • Japanese knotweed - Reynoutria japonica 
    • Giant knotweed - Reynoutria sachalinensis 
    • Bohemian knotweed - Reynoutria x bohemica 
    • Japanese Angelica Tree - Aralia elata
    • Japanese hops - Humulus japonicus
    • Oriental bittersweet - Celastrus orbiculatus
    • Black swallow-wort - Cynanchum louiseae/Vincetoxicum nigrum
    • Pale Swallow-wort - Cynanchum rossicum/Vincetoxicum rossicum
    • Mugwort - Artemisia vulgaris
    • Japanese Barberry - Berberis thunbergii (Grace period until October 8, 2023) (Approved exempted varieties)
    • Garlic mustard - Allaria petiolata
    • Japanese stiltgrass - Microstegium vimineum 
    • Callery pear - Pyrus calleryana (Grace period until February 10, 2024)
    • Eurasian watermilfoil - Myriophyllum spicatum 
    • Common buckthorn - Rhamnus cathartica 
    • Glossy buckthorn - Rhamnus frangula [Synonym: Frangula alnus] (Rhamnus ‘Fine Line’- Approved exempted variety)
    • Lesser celandine - Ficaria verna
    • Burning bush - Euonymus alatus (Grace period until January 10, 2025) 
    • Chinese privet - Ligustrum sinense (Grace period until January 10, 2025) 
    • European privet - Ligustrum vulgare (Grace period until January 10, 2025) 
    • Border privet - Ligustrum obtusifolium (Grace period until January 10, 2025)
    • Amur honeysuckle - Lonicera maackii 
    • Morrow’s honeysuckle - Lonicera morrowii
    • Bell’s honeysuckle - Lonicera x bella 
    • Tatarian honeysuckle - Lonicera tatarica 
    • Standish/Fragrant honeysuckle - Lonicera standishii

Class C Noxious Weeds

    • Water soldier - Stratiotes aloides 

Submit a Noxious Weed complaint.

Plants that have been voted on and approved by the Controlled Plant and Noxious Weed Committee will become official 60 days after publication in the Pennsylvania Bulletin