Invasive Species Guide
The Offender: Autumn Olive (Elaeagnus umbellata)
Origins: Imported from Asia in the 1830’s to reestablish old strip mines because E. umbellata does well in poor soil. However, because of the fact that birds and animals love the berries of E. umbellata, it quickly spread into natural areas.
Habitat: Found in all areas of the natural environments (especially areas with poor soil quality): Forests, fields and meadows, roadsides, forest edges, wetlands, streambanks, yards etc.
Identification: The most defining characteristics of E. umbellata are that the shrub leafs out before most other plants in the spring and when it does the new leaves are silver in color. As the shrub matures the leave turn darker green and the young brown bark turns from brown to light gray.
Environmental Impacts: E. umbellata shades out native species since it leafs out earlier in the spring and its leaves stay on longer that most native species. Also E. umbellata is a prolific seeder; in fact just 1 pound of fruit produces around 2,000 seeds! This allows for E. umbellata to quickly establish itself in an area and spread to surrounding areas easily!
Treatment Options: Hand pulling is an effective measure to control E. umbellata but all of the roots must be removed to prevent re-sprouting and hand pulling is best done when shrubs are young. Grazing with goats can be extremely efficient but unless you personally own goats this option can be expensive depending on the extent of the E. umbellata. Goats will also eat native vegetation as well so keep that in mind when deciding management options. Herbicide foliar treatments, basal bark treatments or cut stump treatments all work when using either a broadleaf specific herbicide or a nonspecific herbicide.
The Offender: Chinese Privet (Ligsutrum sinense)
Origins: Imported from China in the 1850’s as an ornamental yard plant and by the 1950’s it became a prolific invasive species throughout the southern United States.
Habitat: Found in all areas of the natural environments (especially areas with poor soil quality). Forests, fields and meadows, roadsides, forest edges, wetlands, streambanks, yards etc.
Identification: Leaves are evergreen to semi evergreen and are arranged opposite to each other on the branch. Leaves are arranged on a flat plane and resemble a fishbone pattern. Leaves have smooth edges and are glossy green on top and light green on bottom.
Environmental Impacts: Although Ligsutrum sinense seeds are only viable in the soil for less than a year, the shear amount of the seeds produced by the shrub are astronomical and therefore unattended Ligsutrum sinense populations can quickly turn a landscape into a dense thicket of Ligsutrum sinense which out-competes and shades out native species.
Treatment Options: Hand pulling is an effective measure to control Ligsutrum sinense, but all of the roots must be removed to prevent re-sprouting and hand pulling is best done when shrubs are young. Grazing with goats can be extremely efficient, but unless you personally own goats this option can be expensive depending on the extent of the Ligsutrum sinense. Goats will also eat native vegetation as well so keep that in mind when deciding management options. Herbicide foliar treatments, basal bark treatments or cut stump treatments all work when using either a broadleaf specific herbicide or a nonspecific herbicide. Be patient! Ligsutrum sinense probably won’t completely to go away after one treatment and more than likely will take multiple treatments in order to end up with good control.
The Offender: Tree of Heaven (Ailanthus altissima)
Origins: Imported from China in 1748 and was planted in Pennsylvania. By the mid 1800’s A. altissima was available commercially throughout the United States.
Habitat: Found in all areas of the natural environments (especially areas that have been disturbed and have poor soil quality). Forests, Fields and meadows, roadsides, forest edges, streambanks, yards etc.
Identification: Tree that can grow up to 70ft in height and has large alternate compound leaves with 12-25 leaflets. Bark is smooth and light brown to gray. Broken branches and leaves give a very offensive odor when broken. A. altissima has yellow flowers in June and reddish single winged samaras are produced and stay attached for long periods of time. Most trees produce 325,000 seeds a year!
Environmental Impacts: A. altissima is not only a prolific seeder, it can also grow shoots from roots and crowd out native species. It also produces a chemical in the soil (Ailanthone) that acts as an allelopathic herbicide preventing native species from growing near ailanthus allowing for thick groves of ailanthus to take over a landscape.
Treatment Options: Hand pulling is an effective measure to control A. altissima, but all of the roots must be removed to prevent re-sprouting. Hand pulling is best done when shrubs are young and soil is moist. Herbicide foliar treatments, basal bark treatments, cut stump treatments, and hack and squirt treatments all work when using either a broadleaf specific herbicide or a nonspecific herbicide. Be patient! A. altissima probably won’t completely to go away after one treatment and more than likely will take multiple treatments in order to end up with good control.
The Offender: Kudzu (Pueria montana var lobata)
Origins: Kudzu arrived in 1876 to be planted in Philadelphia to cover the Japanese Pavilion. In 1902 it was used as a forage crop and erosion control.
Habitat: Found in all areas of the natural environments (especially areas that have been disturbed and have poor soil quality): forests, fields and meadows, roadsides, forest edges, streambanks, yards etc.
Identification: Large dark green leaves are alternate and have three leaflets. Leaves and stems have golden hairs. Upright reddish to purple flower clusters appear mid-late summer. Taproots can grow up to 7 inches wide and 6-12 feet long.
Environmental Impacts: Kudzu grows 60 feet in a growing therefore it can quickly climb trees and shrubs and take over an entire landscape with ease. It also has larger tubers that supply the plant with nutrients and food.
Treatment Options: Kudzu is very difficult to control - be patient! More than likely it will be multiple treatments before any results seem to appear. Prescribed burns are only effective for young infestations. However, prescribed burns do clear vines in trees and clear the areas for herbicide spraying to be more easily performed. Livestock grazing is effective when Kudzu is young however livestock does not eat the crown of Kudzu and therefore isn’t the best treatment option. Herbicide is the most cost-effective control currently available.
The Offender: Japanese Honeysuckle (Lonicera japonica)
Origins: Native to Eastern Asia. L. japonica was brought to US in 1806 as an ornamental vine in Long Island NY and then in 1990 L. japonica was recommended for erosion control by biologists.
Habitat: Found in all areas of the natural environment: Forests, Fields and meadows, roadsides, forest edges, yards etc.
Identification: L. japonica is a semi-evergreen to fully evergreen perennial woody vine with glossy dark-green oval leaves which are arranged opposite to each other along the vine. The most distinctive characteristic is its showy fragrant yellow and white flowers. These flowers are the flowers that you plucked and sucked out the nectar as a kid!
Environmental Impacts: L. japonica can either create a dense mat on forest floors and meadow areas or more commonly climb shrubs and fences like a ladder in order to grab ahold of tree climbs. L. japonica climbs the trees in order to reach the canopy to receive the most sunlight possible. It then grows into larger sized vines. These larger vines strangle the tree by squeezing the trunk and stopping the flow of nutrients and eventually killing it or toppling the tree over due to the extra weight in the canopy. L. japonica is also a semi evergreen vine and therefore photosynthesizes for a much longer duration throughout the year than most native species giving L. japonica a competitive advantage.
Treatment Options: Manual hand pulling is effective, but the entire plant needs to be removed to prevent re-sprouting from occurring. The more common and best approach is to use a non-selective or broadleaf selective herbicide during fall-early winter before the hard frost (25 degrees Fahrenheit). Early Spring before native plant leaf flush is also a great time to treat this species.
