Forest Health

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.

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.

In our Winter 2019 issue, read our "Woodland Wildlife Spotlight," the "Invasives in Your Woodland" feature, what the 2018 Farm Bill offers for woodland property owners, and how a native fungus that may help control tree-of-heaven.

Japanese barberry tolerates shade, resists drought, and deer don’t eat it. While this sounds like a perfect combination for ornamental planting, because deer do not browse it, it can outcompete native shrubs. It spreads rapidly through woodlands, open fields, and wetlands.

Eurasian bush honeysuckles are non-native species that can out-compete many native plant species. They are found throughout Maryland and the mid-Atlantic states, where these multi-stemmed plants spread rapidly in disturbed areas, forming dense thickets that can reach ten to fifteen feet in height.

English ivy can be found in many areas throughout Maryland and the nation. You can see it in both woodlands and urban areas alike. This climbing vine is a highly aggressive invader that threatens all levels of forested and open area.