Controlling Invasive Shrubs in the Mountains
Thorough guidelines for controlling each of the following species can be found in Cherri Smith's manual distributed by N.C. Department of Transportation.
Please follow this link to get this FREE manual:
http://www.ncdot.org/doh/preconstruct/pe/neu/NEUProcedures/NCDOT_Invasive_Exotic_Plants.pdf
Elaeagnus umbellata (Autumn Olive)
Photo credits (clockwise): Nancy Loewenstein, Auburn University, Bugwood.org; Pennsylvania Department of Conservation and Natural Resources - Forestry Archive, Bugwood.org; Chris Evans, River to River CWMA, Bugwood.org
Autumn olive shrubs have spread all over the east coast, since introduction as an ornamental. Like the thorny olive tree, its tasty fruits make it popular with wildlife and thus, it is easily dispersed. The shrub is dense and shades out native plant species.
The shrub grows to 20'. The oblong-shaped leaves (1" long) are silvery on the underside. In spring and early summer, white or yellow tubular flowers bloom in clusters. Small, red fruits appear in the fall.
The shrub grows to 20'. The oblong-shaped leaves (1" long) are silvery on the underside. In spring and early summer, white or yellow tubular flowers bloom in clusters. Small, red fruits appear in the fall.
Lespedeza bicolor (Bicolor/Shrub Lespedeza)
Photo credits (left to right): David J. Moorhead, University of Georgia, Bugwood.org; Chris Evans, River to River CWMA, Bugwood.org
Shrub lespedeza is found throughout the southeast and all over the state of North Carolina. It is most prevalent on the coastal plain and in the piedmont. Birds disperse its seeds. It thrives after burning, making it a formidable competitor with native vegetation in burned sites. The shrub sometimes forms thickets in open areas.
It grows to a height of 10'. It is identified by its loose, arching branches, compound leaves (groups of 3 oblong-shaped leaves) which are arranged alternately around the stem, and its clusters of magenta flowers (blooming in the summer, 0.5" long). Seed pods are produced in the fall.
Ligustrum sinense (Chinese Privet)
Photo credits (left to right): Troy Evans, Great Smoky Mountains National Park, Bugwood.org; Chris Evans, River to River CWMA, Bugwood.org
Chinese privet grows along roadsides, in woods, bottomlands, and along streams in the Piedmont and in all other parts of the state. It can form dense thickets which effectively wipes out the herbaceous vegetation.
The shrub produces a small black fruit in late summer, early fall which is consumed by birds; birds are the most effective dispersers for this aggressive plant. Besides the black fruit, the shrub can be identified buy its oval-shaped leaves which grow oppositely along the branches. The leaves are dark and glossy on the top surface and pale on the underside with a hairy midrib. The shrub grows up to 15' and has smooth gray or tan bark. In mid-summer, the tree produces small white flowers which grow in clusters at the end of each branch.
The shrub produces a small black fruit in late summer, early fall which is consumed by birds; birds are the most effective dispersers for this aggressive plant. Besides the black fruit, the shrub can be identified buy its oval-shaped leaves which grow oppositely along the branches. The leaves are dark and glossy on the top surface and pale on the underside with a hairy midrib. The shrub grows up to 15' and has smooth gray or tan bark. In mid-summer, the tree produces small white flowers which grow in clusters at the end of each branch.
Reynoutria japonica (Japanese Knotweed)
Photo credit: Leslie Seiger, San Diego Mesa College, Bugwood.org
Japanese knotweed has invaded the eastern United States and southern Canada. In the mountains and in the Piedmont of North Carolina it is most common in open habitat along streams and in floodplains. It disperses mainly as seeds and rhizome fragments through flooding.
Japanese knotweed forms small shrubs (10’) with smooth hollow stems, reminiscent of bamboo. Its leaves (6” long and 3 – 4” wide) are oval but taper to a point. Small, white flowers grow in spikes in late summer and early fall.
Rosa multiflora (Multiflora Rose)
You can distinguish this rose from native
wild roses by its feathery stipules. Photo credits (from left to right): James H. Miller, USDA Forest Service, Bugwood.org; Chris Evans, River to River CWMA, Bugwood.org
Past efforts to use this rose shrub as live fencing in pasture land has made it a problem in current pasture lands, successional fields, and in other open habitats throughout the state.
The shrub grows to 10' and has arching, thorny stems. The compound leaves are made up of 7 to 9 leaflets (1 - 1.5") arranged in an alternating fashion along the leaf stem and a terminal leaflet. The leaflets are oval with serrated edges. A distinguishing feature is that the stipules, the green growths at the base of leafstalks, are feathery. The 5-petaled flowers bloom in May or June and are fragrant, white or pink, and about 1" diameter. Bright red rosehips develop during the summer and can stay on through the winter. As they dry out they become leathery and brown.
The shrub grows to 10' and has arching, thorny stems. The compound leaves are made up of 7 to 9 leaflets (1 - 1.5") arranged in an alternating fashion along the leaf stem and a terminal leaflet. The leaflets are oval with serrated edges. A distinguishing feature is that the stipules, the green growths at the base of leafstalks, are feathery. The 5-petaled flowers bloom in May or June and are fragrant, white or pink, and about 1" diameter. Bright red rosehips develop during the summer and can stay on through the winter. As they dry out they become leathery and brown.
Spiraea japonica var. fortunei (Japanese Spiraea)
Photo credit: Great Smoky Mountains National Park Resource Management Archive, USDI National Park Service, Bugwood.org
Japanese spirea has dispersed throughout the eastern United States, including in the mountains of North Carolina. It is most common in moist, open forests. Seeds are dispersed through water, making it common along stream banks.
Japanese spirea has beautiful pink flowers which make it a popular ornamental. These flowers grow in clusters in midsummer. Leaves are oblong and serrated (1 – 3” long). The shrub grows to 3 - 6’ tall.
Japanese spirea has beautiful pink flowers which make it a popular ornamental. These flowers grow in clusters in midsummer. Leaves are oblong and serrated (1 – 3” long). The shrub grows to 3 - 6’ tall.
Tamarix ramosissima (Salt Cedar)
Photo credit: Steve Dewey, Utah State University, Bugwood.org
Salt cedar is an invasive from Africa that is mostly a problem in western and central United States but it is also invasive in the south’s riparian zones, wetlands, and coastal areas.
Salt cedar can grow between 5 – 20’ in height. The bark of young trees is smooth and reddish but it grays and becomes rougher as the shrub ages. Tiny, grayish-green leaves overlap along the stem. Pinkish white flowers bloom from spring to late summer.
