Invasive Plants or Trees

Tree-of-heaven has been receiving a significant amount of attention lately, and not just because it is a fast-spreading invader of woodlands throughout the mid-Atlantic states and beyond. the recent discovery of a new invasive insect in Pennsylvania, and its subsequent spread into adjoining areas, has lent new voice to advocates for the plant’s removal. Spotted Lanternfly, a recent arrival from Asia prefers tree-of-heaven as its host. This has led to an increased movement to remove tree-of-heaven from the landscape.

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.

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.

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

Multiflora rose is one of the most common invasive plants in the mid-Atlantic region. Read how to identify it, how to keep it from spreading, and how to keep it in check.

Like many invasive plants in North American woodlands, Oriental bittersweet is a strong competitor for light and nutrients in a variety of disturbed landscapes. It can be found along roadsides, in fallow fields, and in woodlands that have been recently harvested.

Drive along many of Maryland’s major roads in the spring, and you will see what seems like a wall of white, as the Callery pear (and its offshoot, the Bradford pear) are in bloom. While these may be an impressive sight, these trees are an invasive and highly competitive species.