In one of the best examples of promotion gone terribly, terribly wrong, kudzu — lovingly referred to as 'The Vine that Ate the South' — was once touted as a miraculous combination of forage crop, erosion controller and ornamental vine that just happened to come with a refreshing grape scent.
Fast forward 100 years, and the vine, native to Japan, is smothering the southeastern United States in a canopy of 4-inch, emerald green leaves. Listed by Congress as a "federal noxious weed" in 1998, kudzu has infested an estimated 7 million acres between Texas and New York. Its infestations are most extreme in Mississippi, Alabama and Georgia, where it routinely overtakes power lines, abandoned automobiles and even entire buildings. "The damage it has caused is in the millions," Stewart writes in Wicked Plants, "At the Fort Pickett military base in Virginia, kudzu overwhelmed two hundred acres of training land, (and) even M1 Abrams battle tanks couldn't penetrate the rampant growth."
Growing a foot per day during its main growing season, kudzu kills any shrub or tree in its path via a 3-pronged attack. First, its dense blanket of foliage deprives underlying vegetation of sunlight. The woody vine can also "girdle" the victim's trunk by stripping off the bark and associated membranes and, in turn, starving the plant by disconnecting the nutrient transport system between leaves and roots. Finally, the sheer weight of kudzu delivers a final lethal blow as it breaks off branches and even uproots entire trees.
So far, attempts to subdue the green invader are too costly to be effective on a large scale. Because kudzu plants repeatedly resprout and their seeds can go years before germinating, mowing, grazing and herbicide treatments require multiple applications over multiple years. Physically removing the plants by digging up root systems is extremely energy intensive (the tap root alone can be 300 to 400 pounds) and, like controlled burns, not feasible in highly erodible terrain. Finally, the use of foreign insects, fungi and pathogens as biological control is often met with resistance as such applications can result in unforeseen ecosystem damage and new invasive species problems.
But the news about kudzu isn't entirely bad. The plant's leaves, flowers and stems are all edible, so it was only a matter of time until fried kudzu and other southern delicacies were created using the vine as the main ingredient. And a 2005 Harvard Medical School study even found that a compound extracted from kudzu root helps suppress the amount of alcohol a person wants to drink, and may aid in the treatment of alcoholism.
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