​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

• Ravenna grass - Tripidium ravennae [Synonym: Saccharum ravennae] [Synonym: Erianthus ravennae] (Grace period until September 2022)
  
• 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 undulatifolius
  
• 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

Class B Noxious Weeds

• Common buckthorn - Rhamnus cathartica
• Glossy buckthorn - Frangula alnus - [Synonym: Rhamnus frangula] - (Grace period until February 2023) (Accepting exemption applications for sterile cultivars)
• Callery pear - Pyrus calleryana
• Eurasian watermilfoil - Myriophyllum spicatum
• Bull thistle or Spear thistle - Cirsium vulgare
• Canada Thistle - Cirsium arvense
• Musk Thistle or Nodding Thistle - Carduus nutans
• Johnsongrass - 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
• Parrot feather - Myriophyllum aquaticum
• 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 - Vincetoxicum nigrum [Synonym: Cynanchum louiseae]
• Pale Swallow-wort - Vincetoxicum rossicum [Synonym: Cynanchum rossicum]
• Mugwort - (Artemisia vulgaris)
• Japanese Barberry - Berberis thunbergii - Approved Exempted Cultivars
• Japanese stiltgrass - Microstegium vimineum 
• Garlic mustard - Alliaria petiolata

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