Invasive Woody Plants

Since its debut as a regular Branching Out feature in 2016, "Invasives in Your Woodland" has profiled a wide variety of invasive plant species that threated the health of Maryland's ecosystems.

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.

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.

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.

The Norway Maple is so conspicuous throughout the United States that it is often easy to forget that it is an introduced species that can adversely affect the environment.