Invasive Plants or Trees

Garlic mustard is a biennial flowering plant in the mustard family that is an aggressive invader of woodlands throughout the United States.

Afforestation is the process of planting trees in formerly open space. Because trees take time to mature, it is important to ensure that the seedlings have sufficient light and nutrients to grow. This often involves controlling growth of other species within the planting area, including invasive species such as the distinctive Johnsongrass. And once established in an area, Johnsongrass can out-compete many other species for nutrients and over-top them to rob them of sunlight.

Japanese privets are less common than other privets that are more widespread across the eastern U.S. Reported sightings in the mid-Atlantic are sparse, but it may be more widespread, based on its continued use in landscaping.

Winged euonymus is not widespread in the mid-Atlantic. Its greatest reported infestations are in the Midwest and Northeast. It has been found in much of central and southern Pennsylvania, far northern Delaware, southwestern Virginia, north-central West Virginia, and the greater Washington DC area.

European buckthorn is a native of Europe and was introduced here as an ornamental plant, perhaps as early as the late 1700s. In the 1900s, it was planted widely to form living fence rows and for wildlife habitat. Since then, it has spread aggressively into a variety of environments.

Butterflybush is a rarity among non-native, invasive species. It has a wide variety of cultivars and a wide range of supporters among retail outlets as well as some environmental observers. It is also benefitting from positive public relations related to the decline of butterflies. However, it is indeed invasive, and contributes to (rather than mitigates) the decline of pollinators.

Japanese knotweed is an upright, shrubby, herbaceous perennial plant that can grow to over ten feet in height. It commonly invades disturbed areas with full or mostly full sunlight, such as roadsides. However, it can tolerate shade, as well as high temperatures, high salinity, and drought.

Kudzu is a deciduous, climbing, semi-woody perennial vine that grows 35 to 100 feet long. It grows via runners, rhizomes, and from nearly every node that touches the ground. It spreads most rapidly in open areas, including disturbed areas such as abandoned fields, roadsides, and forest edges.

Japanese honeysuckle grows in a variety of habitats, including woodlands, wetlands, and disturbed areas, such as fence rows, roadways and rights-of-way. It is shade-tolerant and often smothers and kills native ground-level vegetation. It can also kill shrubs and saplings by girdling.

Autumn olive is now considered an invasive plant species for a variety of reasons. While it is not illegal to sell the plant in every jurisdiction where it exists, many natural resources management agencies and organizations discourage property owners from further planting.