Invasive Plant Control

Most of the following information was taken from a pamphlet produced by Maryland Cooperative Extension, University of Maryland. Home and Garden Information Center, 1-800-342-2507

What are Invasive Plants?
Some plants introduced to our country have escaped control to become invasive and destructive. Known as non-native, exotic, or alien invasive plants, they spread unchecked because their natural controls - disease and predators - were left behind in their land of origin.

Invasive plants threaten our native plants and animals. Some native plants face extinction. Native wildlife suffers because it evolved dependent on native plants for food and shelter.

How are Invasive Plants Controlled?
The best and easiest control is early identification and quick removal. This includes pulling up as much of the root as possible.

Invasive Plants Identification
The following is a list of invasive plants common in our local parks. Your help to remove them is important to protective our native species and keeping our parks in their natural state.

1. Multiflora Rose
multiflora rose This Asian rose chokes out natives. Flowers are white. (native roses are usually pink.) It forms impenetrable stands.

Cut to ground. Dig up seedlings and moderate-size plants. For extensive infestation, spray foliage with glyphosate with spreader sticker, or treat freshly cut cane stumps with glyphosate.

2. Honeysuckles
honeysuckle honeysuckle
Flowers are white and gold. (native species are scarlet-flowered).
Cut to ground. Pull up seedlings and moderate-size plants.

The wild grape is native to North America and should be saved. It provides food for many species of animals.
If in the way of the trail, tie it back.
The vine can be identified by its long stringy bark. grape vine

3. Porcelainberry Vine
DESCRIPTION: Porcelainberry is a deciduous, woody, perennial vine. It has a smooth bark. The plant climbs by tendrils that grow opposite the leaves on the stem. Small, greenish-white flowers appear in clusters on porcelainberry in June, July, and August. The colorful berries of porcelainberry, its most distinguishing feature, appear in September-October. The berries, about 1/4-inch in diameter, range in color from white to yellow, to pastel shades of green, lilac and amethyst purple, to turquoise and sky blue. porcelain berry vine
ECOLOGICAL THREAT: Porcelainberry is a vigorous vine which is slow to establish but grows and spreads quickly in open areas of the urban landscape. Once established, the vine quickly overwhelms and destroys native vegetation by shading out smaller plants and outcompeting native vegetation for water and nutrients. Urban parks, with extensive wooded borders neighboring landscaped residential and private property, are especially vulnerable to invasion by porcelainberry.
Cut aboveground vines and, if possible, pull from trees to allow the trees to recover and recut repeatedly as needed.

4. Japanese Barberry (Prickerbush)
prickerbush barberry winter This bush grows two to three feet tall. In the fall it produces red berries When you cut its stems, you will note that they are bright yellow.

Cut to the ground. Dig up seedlings and moderate-size plants.

5. Mile-a-Minute Vine / Devil's Tear Thumb
Tear thumb This barbed annual vine, native of Asia, can grow 25 feet in a season. It has turquoise berries.
Pulls easily by hand, use heavy gloves. Use glyhosate on extensive growth.

6. Vietnamese/Japanese Stiltgrass
Stiltgrass Bright green grass has silver hairs down the center of its short bamboo-like blade. In fall, this Asian annual elongates quickly, then produces seed banks which stay viable in the soil for years.
Hand pulls easily - very little root.

7. Canada Thistle, Bull Thistle
Thistle This perennial (Canada) and Biennial (Bull) prefer full sun and quickly form dense patches with purple or pink flowers. They serve as hosts for insect and disease pests. They are official noxious weeds in Maryland
Their extensive root system makes hand pulling useless. Any piece of root will create a new plant. If possible, hand-dig seedlings in soft soil. Do not allow to flower or remove flower before the seeds form. Apply glyphosate to foliage or fresh-cut stems.

8. Garlic Mustard
Garlic mustard poses a severe threat to native plants and animals in forest communities in much of the eastern and midwestern U.S. Many native wildflowers that complete their life cycles in the springtime (e.g., spring beauty, wild ginger, bloodroot, Dutchman's breeches, hepatica, toothworts, and trilliums) occur in the same habitat as garlic mustard. garlic mustard Once introduced to an area, garlic mustard outcompetes native plants by aggressively monopolizing light, moisture, nutrients, soil and space. Wildlife species that depend on these early plants for their foliage, pollen, nectar, fruits, seeds and roots, are deprived of these essential food sources when garlic mustard replaces them. Humans are also deprived of the vibrant display of beautiful spring wildflowers.
Due to the long life of its seeds in the soil, which may be five years or more, effective management of garlic mustard requires a long term commitment. The goal is to prevent seed production until the stored \seed is exhausted. Hand removal of plants is possible for light infestations and when desirable native species co-occur. Care must be taken to remove the plant with its entire root system because new plants can sprout from root fragments.

9. Retired Tire (L. Etiredray Iretay)
retired tire This invasive species may be found in a variety of habitats, from creek bottom to upland woods. It is not susceptible to toxic sprays but must be pulled up and removed. Its flower and seed remain a mystery to science.



This page was last updated on 2.10.05