One of the most visible and well-known invasive plants in our area is kudzu. It aggressively grows and can cover just about everything in its path, including large trees and abandoned structures.
It crowds out native vegetation and can disrupt wildlife habitats. Kudzu kills other plants by smothering them, by girdling woody stems and tree trunks and by breaking off or uprooting entire trees and shrubs because of its weight. The individual kudzu vines are capable of reaching lengths of more than 100 feet and can grow as much as one foot per day under optimal conditions.
It can grow in almost any type of soil, but prefers moist soils of almost any type, although the large root systems allow it to survive prolonged periods of drought conditions.
Kudzu was imported from Asia in the early 1900s and was planted throughout the Southeast along the sides of roads, railroads and farmland for erosion control as well as a source of forage for livestock. The government encouraged farmers in the South to plant kudzu to reduce soil erosion and Franklin Roosevelt's Civilian Conservation Corps planted it widely for many years. It was also a popular ornamental vine due to its beautiful leaves and purple flowers which resemble wisteria.
Controlling kudzu can be a real challenge since it is a perennial weed. It has a large underground root which takes time to kill with the ability to store food reserves. Continued pruning it back to the ground, or in some cases, mowing, will eventually deplete the vine of its stored energy in its roots.
August and September are an excellent time to control kudzu with a chemical herbicide since the leaves are taking food material and transporting it deep into the vine's root system for the winter. The best chemicals for controlling kudzu are Round-up and any herbicide with the active ingredient triclopyr, sold under names like Bayer Advanced Brush Killer Plus, Ortho MAX Poison Ivy and Tough Brush Killer, and others.
Spray the leaves with these chemicals until thoroughly wet. You can also cut the individual plants back to the ground and coat the cut stump with undiluted triclopyr. There are formulations sold just for this purpose. This method works especially well in controlling kudzu that is growing beds of shrubs and flowers, since the herbicide will also kill desired plant material as well. Poison ivy, greenbriers, privet, and other woody plants can be similarly controlled in this manner. Both methods of applying the herbicides may require more than one application.
Another way to control the vines is in the winter months, while the vine is dormant cut back the individual kudzu vines. In May, spray the kudzu shoots when the leaves have fully opened up and is about the size of your hand and then do so again in late summer to control the re-growths. Please make sure you follow all label directions and safety precautions when using chemical pesticides.
If you have very large areas of kudzu, you may need to hire a landscape contractor that has the expertise and resources to control and remove it from your property. You can find one through the Web site of the Metro Atlanta Landscape Turf Association (MALTA) at www.maltalandscape.com.
Despite of the rapid, aggressive growth of kudzu, it can be brought under control and prevented from overtaking your property. Constant vigilance is a must since event after the vine has been eradicated it has the potential to return from old root growth and vegetative growth. For more information on kudzu, please contact the Gwinnett County extension office.
Timothy Daly is an agricultural and natural resource agent with the Gwinnett County Extension Service. He can be reached at 678-377-4010 or firstname.lastname@example.org