Kudzu

(Photo taken by Andrew Kirby)

Kudzu is a tri-leaved, semi-woody, perennial vine that has the capacity to either trail or climb. Vines may grow up to 60 feet in a single season (1 foot each day under ideal conditions); they advance from root crowns and spread in all directions, rooting and forming new vines every few feet. A single drown may produce as many as 30 separate vines. Each kudzu plant has been scattered by seed, vine cuttings or crown transplants. The seeds are spread by pods that form in July to October from the fragrant flowers. These seeds mature on the vines during October and November and can lie in the kudzu patch for many years before they germinate, complicating eradication efforts. There are roughly 17 species of kudzu known worldwide, they are all native to China, Taiwan, Japan, and India. It is estimated that kudzu has invaded over 7 million acres of land in the Southeast. It has spread as far north as Illinois, Pennsylvania, West Virginia, and up to Connecticut and as far west as eastern Texas and central Oklahoma. (Although there have been increasing reports of its growth in Oregon.) This infestation is most unrelenting in Alabama, Georgia, and Mississippi. The reason for its concentration is ideal weather condition; hot, rainy summers with few freezes in the winter.

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  Where did it come from?

Kudzu made its US debut in the 1870’s during an exhibition on plants. Due to its rapid growth and beautiful flowers, it evolved into a popular vine for shade in Southern porches during the late 19th century. Careless agricultural acts and expansive cotton farming in the South established the problem of soil erosion. As an incentive to resolve this issue during the 1930’s, the US Government’s Soil Erosion Service doled out money to farmers for each acre of kudzu they planted. They also gave out over 80 million free seedlings. For the next few years it was celebrated with festivals along the South, one of its most spoken advocates was Channing Cope of Covington, Georgia. Known as the “Kudzu King”, he was quoted as saying that kudzu had replaced cotton as the crop of the south. He also wrote articles for the Atlanta Journal Constitution proclaiming its virtues and traveled the southeast to create clubs in honor of the plant. He was very disappointed when eventually, during the 1950’s; its rapid expansion began to be recognized as a problem. The Department of Agriculture removed kudzu from the list of cover plants permissible under the Agricultural Conservation Program in 1953. It wasn’t until the 1970’s that The Department of Agriculture listed kudzu as a common weed and in 1997, Congress voted to place kudzu on the Federal Noxious Weed list.

• Why is it such a Problem?

A recent study at Clemson University concluded with the opinion that lands infested with kudzu are only good for growing more kudzu. It is a plant that will cover and choke everything in its path, eliminating native species. The weight of the vines can bring down tree limbs, power lines and even collapse buildings. The Congressional Office of Technology estimated the economic costs of Kudzu at $50 million annually. Control costs are estimated to increase by about $6 million per year.
Methods for successful removal of Kudzu are still being experimented but there are proven methods that generally require a lot of patience. One such method is the removal or killing of the crown root. Mechanical methods involve cutting off crowns from roots, usually just below ground level, immediately killing the plant. It is necessary to destroy all removed crown material: One common way that kudzu spreads is through soil transported from a kudzu infestation, buried crowns actually regenerate into healthy kudzu.
For younger patches in accessible terrain, mowing or grazing proves successful over time. This tactic is known as defoliation and over three or four years can eliminate kudzu when at least 80% is consumed continuously. Also effective is mowing every four to six weeks during the growing season.
Herbicides are the only other method of control but special considerations must be taken, especially in relation to the area where the patch is located. Debris must be cleared and Timber must be logged first before the appropriate herbicide can be applied. Burning is also an old method for clearing the area. With regard to what type of herbicide to use, consideration must be taken for the age of the plant (which can be determined by the crown) and the type of soil at the infestation site. To determine if an herbicide may be used, it must be understood whether other plants will be introduced to the area eventually, what other plants may be injured or killed by the chemicals and if there is a possibility of contaminating streams or groundwater. Retreatment is also expected to ensure lasting success, often for up to 10 years.

• A New Way of Thought

If it is such a burden and there are no easy ways to eradicate kudzu, it makes sense for us consider the possibility of its use. Researchers at Tuskegee University have raised goats in fields of kudzu which would otherwise be considered wasted land. Kudzu produces forage that is high in quality and quite palatable to livestock. In turn, the goats keep the kudzu from spreading further while producing profitable milk and wool products. Because of its nutritional value, kudzu can be fed to most livestock as a high-quality, high-protein food similar to alfalfa. If kudzu is to provide a continuing food source, animals must be removed from the fields occasionally to allow the vines time to grow, although they grow quickly the edible leaves usually only produce around 2 to 4 tons of dry matter per acre per year.
Oriental cultures have valued Kudzu for thousands of years. Records in China refer to kudzu (known then as gen-gen) medicinal purpose as early as 1578. Fiber found in the stems was used to make cloth and paper during the 17th century. In the Orient, writings that date as far back as 100 AD express its use for treating dysentery, allergy problems, headaches, diarrhea, fevers, colds, tinnitus, vertigo, to help with digestion and reduce blood pressure. Today, experiments show that a compound in kudzu actually causes the repression of alcohol consumption. This research could have great value in the future for the treatment of alcoholism.
One of the more common uses for Kudzu is basket-making. The vines are malleable enough to be woven or manipulated until they dry and harden. There are also people along the southeast who make their own soaps and lotions. The most interesting products, though, are the food products which have been developed; Kudzu was introduced to Japan in the 1700’s where it was used to make cakes. Today we boast recipes for teas, syrups, jellies, stewed roots, pickled flowers, fried kudzu, casseroles, corn bread, kudzu tofu… The list goes on. It is also a popular thickening ingredient similar to corn starch.

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Be sure to check out-

http://www.youtube.com/watch?v=_Ms2vzbG27I

A wonderful video from our friends at The Science House

http://www.science-house.org/

(Thank you Beth!)