The PA Department of Agriculture added Japanese Barberry, or Berberis thunbergii, to a list of noxious weeds — plants that cannot be legally sold or cultivated in the state. The popular, non-native, ornamental shrub forms dense, prickly thickets that crowd out plants and disrupt native ecosystems. It is also thought to harbor black-legged ticks that spread lyme disease. The ban on sale and cultivation took effect October 8, 2021. Enforcement of the ban will be phased in over two years to allow time for nurseries to eliminate it from their stock, find non-harmful alternatives, and develop seedless, sterile varieties that pose less threat to the environment and agriculture. Landscape and nursery businesses will receive notices of the timeline, procedures and exemption process for sterile varieties. Property owners should consider eliminating the shrubs on their land.
Effective October 8, 2021, the department added two other plants to the noxious weed list: garlic mustard, Alliaria petiolata, and Japanese stiltgrass, Microstegium vimineum. These plants are generally not sold in nurseries but are invasive and common in Pennsylvania. Landowners with these plants on their property are encouraged to remove them.