Invasive Plants in the Landscape

We are being invaded! Not by some foreign country or aliens from outer space, but by plant species not native to our area. The National Park Service and the U.S. Fish and Wildlife Service classify invasive plants as “alien species whose introduction does or is likely to cause economic or environmental harm or harm to human health.”

The problem with non-native plant species is there are no naturally occurring growth controls such as animals, insects, or diseases. Since non-native plants have no natural controls to prevent growth, these plants spread rapidly and frequently crowd out more desirable native plant species which, in turn, causes a loss of natural wildlife habitat.

Ironically, many of the plant species now considered as invasive were originally brought to this country for ornamental, medicinal, or industrial purposes. European settlers would often bring plants from their countries when they came to America. Throughout most of the 19th century and into the 20th century, plant collectors would return from their travels to the Orient with new species of plants.

Unfortunately, some plants, shrubs, and trees that are commonly used to landscape residential properties are now considered invasive species. Stands of bamboo are found growing in a number of locations in this area.

Vines such as English Ivy, Periwinkle (Vinca), Japanese Honeysuckle, Japanese Wisteria, and Oriental Bittersweet are still available for landscape use even though these plants can take over gardens or natural areas.

The Bradford Callery Pear, which signals the arrival of spring with its profusion of white flowers, will reproduce and crowd out desirable native vegetation with its dense shade. Non-native Norway Maples and Mimosa trees are frequently used in the suburban landscape and are now considered invasive trees.

 In order to reduce or eliminate the spread of invasive plant species it is helpful to learn to identify the aggressive, non-native plants growing in our yards and environment.

The National Park Service and U.S. Fish and Wildlife Service has available a well-written, illustrated, and updated handbook “Plant Invaders of Mid-Atlantic Natural Areas.” This book contains valuable information on identifying, controlling, and eliminating invasive plants as well as offering a listing of native plants to use in place of non-native plants.

Controlling non-native plants can be done by treating the plants with an herbicide, such as glyphosate (RoundUp), or removing plants by digging and pulling where practical. If an invasive plant species has infested an area to the point that using an herbicide is the best course for removal, then please remember to consider its effects on the environment, follow the instructions listed on the label or contact a professional to do the application and removal.

Once the invasive plants have been removed it is best to use native plant species when replanting the area.

There is a list of suitable native plants for Anne Arundel County that can be found online here. This list provides both scientific and common names of native plants and categorizes the plants by groundcovers, vines, ferns, grasses, perennials, shrubs, and trees. Using native plants, instead of non-native invasive plants, benefits our environment and improves wildlife habitat.