I’m often asked by homeowners about how to get rid of a particular plant that has taken over a large area of their yard or garden. They may know, or may have just learned, that it is considered “invasive.” When they describe it, I usually can identify it in my mind and guess one or more species that there are likely to be there, as well. I know that these are not only invasive, but are also non-native species that were introduced into North America, either deliberately or accidentally. Most of these were introduced after 1970, and a number of them are a problem across much of the eastern U.S.
When I conduct a site survey for property owners, they are often astonished to learn that they have anywhere from three to 10 different non-native invasive plant species (NNIP) mixed in with the native trees, shrubs, and herbs on their site. They did not know about these plants nor could they identify them.
Well, if you would like to do some detective NNIP botanizing on your own personal piece of paradise, the winter months are a great time to do so. Most of our native Southern Appalachian plants are deciduous, becoming dormant and turning brown or even disappearing into the soil as compost by December and January. Many NNIP, however, are evergreen or semi-evergreen, so come winter, they will stick out like a sore thumb (or maybe an invasive thumb?), and you can easily learn to ID them. Spending a little time to gain this skill now, will make it much easier to pick them out among the warm weather mix of natives and non-natives in the parts of your yard you consider an impenetrable “jungle” during the summer months. Let’s look at some of the ones you can easily learn.
Privet Species
(Ligustrum Spp.)
Several species of privet have been introduced to our area. Chinese Ligustrum sinensis, European, L. vulgare, and Glossy privet, L. lucidum, are the most common. The thing to remember is that there are NO native species of privet in the U.S., so get rid of any you might see in your yard when planting your native garden.
Multiflora Rose
(Rosa multiflora)
Multiflora rose was introduced as a "living fence" substitute for barbed wire, due to its formidable thorns. Also used in highway medians to block oncoming headlights, the shrub grew so thick it could stop out of control vehicles there. Both uses were halted when it was found to completely take over such open areas.
Most roses have a widened "wing" where the petiole (leaf stem) joins the main stem. They also have two fine hair-like "stipules" growing toward the leaves at the end of this wing. But multiflora rose also has numerous stipules growing all along the wing, similar to eyelashes. This, and its hooked thorns offer a positive ID for the plant.
If you can't for any reason focus on removing multiflora rose at the end of a growing season, it's a good idea to clip the berry-producing branch tips, bag them, and throw in the trash, so they will be buried deep in the landfill. This will prevent hundreds of these "rose hips" from germinating in your yard in the future.
Oriental Bittersweet
(Celastrus orbiculatus)
Oriental bittersweet is a bigger threat to forest ecosystems than kudzu, the non-native invasive "poster child." The reason for this is that kudzu seeds are not spread quickly by wildlife or wind, but mainly from a slowly spreading underground root. And it requires full sun. Bittersweet seeds are prolific and spread widely by birds. These can easily sprout and grow quickly under a shady forest canopy.
Oriental bittersweet vines can easily strangle tree saplings and overcome native shrubs and trees by covering those canopies with their own foliage and robbing most of the sunlight. Even though the leaves are gone in winter, these twisted dimpled vines can still be seen then. Though the practice is losing favor, the vines and berries have been used in making Christmas wreaths. Once the holiday passed, these wreaths were often tossed into the wooded edges of yards, creating a nightmarish jungle of vines within a very few years.
Nandina, or
Heavenly Bamboo (Nandina domestica)
Invasive nandina shrubs were brought to the U.S. for landscaping because of their showy clusters of orange-red berries. Unfortunately, their berries contain cyanide, which is toxic to bird species that feed on numerous berries at once. In April 2009, dozens of cedar waxwings were found lying dead in Thomas County, Georgia. A necropsy revealed only nandina berries in their stomachs and deadly levels of cyanide in their tissue. Please remove these plants if you have them!
Porcelainberry (Ampelopsis brevipedunculata)
Porcelainberry is a non-native vine that sneaks into gardens undetected for a couple of years. Then, come fall, it announces itself with noticeable, and
yes, very pretty, berries. Their color resembles that of late 1900's dinnerware with blue-tinted designs. Similar to grape leaves, Porcelainberry foliage seems to cleverly disguise itself among cultivated grape arbors.
Autumn Olive (Eleagnus umbellatum)
Autumn olive was once planted by national forests, state wildlife agencies, and some private landowners, to provide food for game species within designated wildlife fields. But these agencies and other botanists noticed that this large shrub soon took over these areas and forest canopy borders, displacing native habitat. Such plantings have been largely halted, but the "cat is out of the bag" and autumn olive is showing up in many residential neighborhoods.
These are just a few of the 30 or so problematic non-native invasive plants in our Blue Ridge Mountain communities. This article will, hopefully, help you identify those that are more easily visible during winter months. Good luck hunting for them, and I hope you don't find them!!
For more information on non-native invasive plants, NNIP removal, and replacement with native insect and wildlife attractive plants, visit "Services" at http://www.restoraflora.com/
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