The Life and Lies of Kudzu

Southerners see it everywhere: green tentacles snaking up the road signs, vines suffocating vast green meadows of trees. The infestation has become a trademark of the south: kudzu. Many Americans grow up hearing that kudzu was imported for erosion control, but the true story is more complex.

For the celebration of the hundredth year since the signing of the Declaration of Independence, the Japanese brought many ornamental plants, including kudzu, to Philadelphia in 1876 at the Centennial Exposition. The Japanese use the vine’s fiber to make clothing, paper, and other goods, but Americans were attracted to kudzu’s aesthetic. The lush vine and its aromatic flowers impressed gardeners visiting the exhibit, who  introduced it to American gardens as an ornamental shade vine.

Let me call you sweetheart under the old kudzu vine, an article in the Fair Play (St. Genevieve, MO), 1919

Growing as fast as 60 feet per season, kudzu became a sensation in 1893 when newspapers cited it as the fastest growing vine in the world.  Home gardeners started finding the plant to be too tenacious for arbors and home gardens and were busy getting rid of the unstoppable weed.

After kudzu lost popularity as an ornamental, local governments suggested it as a forage crop because it grows well on poor and rocky soils. Forage crops are a special group of crops that farmers grow widely over large expanses of field and use to feed livestock.  

Kudzu has all the attributes of a good forage crop. First, it’s a legume, so it’s capable of fixing nitrogen and adding nutrients back to the soil. Secondly, kudzu propagates easily by stems and vegetative growth, even without roots. Furthermore, each cutting can grow 10 to 25 feet in the first spring and summer, growing as much as 60 feet per season after three years. Finally, kudzu isn’t limited to the south since it grows as far north as Canada.

In addition to suggesting it as a forage crop, farmers put kudzu to work again in the mid 1930’s with the rise of the dust bowl. The newly formed Soil Conservation Service lauded growing kudzu as a means of erosion control. Farmers raised and planted thousands of kudzu cuttings in nurseries for construction workers to use widely to protect the structural integrity of banks while building railroads and highways across the country. While it provided success against erosion on embankments, kudzu was losing popularity quickly as a forage crop.

Despite its early promise, kudzu couldn’t handle sustained feeding. Livestock grazing severely stunted its summer growth, and it had a hard time regrowing between feeding seasons. So kudzu was ditched as a forage crop in the mid 1940’s. The government ceased subsidizing farmers to plant it, who replaced it as an agricultural commodity with higher yielding crops.  

Despite its appeal in southern literature and myths passed around by many, kudzu is not actually the major invasive weed that old scientific literature would have us believe. Many accounts state that there are 7 million acres of kudzu vines across the United States, but it’s estimated that kudzu covers only 227,000 acres. Furthermore, the Forest Service estimates that kudzu only grows at a rate of 2,500 acres a year, not the popular and outstanding 150,000 acre/year estimate. Also unlike many invasive species, kudzu has a new predator.  The kudzu bug, another recent invasive species and pest of soybeans, sucks the sap out of the vine and leaves it to wither.

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Image: Robert Michalove, Flickr

If the myths behind kudzu are false, why have they pervaded our culture so thoroughly? Kudzu thrives on roadsides, where it engulfs trees and telephone polls, but it cannot easily eclipse shady forests. Though not a concern, its prevalence makes it a poster child for other invasive species.

Perhaps we should turn our mania to serious invasive weeds of the south, such as Chinese privet, an ornamental bush that’s likely  growing in your backyard right now. Despite being considered a very invasive crop by the forest service, nurseries continue to grow and sell it. Unlike kudzu, privet easily slips its way into forests and outcompetes native flora.  It is additionally a larger concern than kudzu because it grows more readily from seed and is transported by birds from backyards into forested areas of the southeastern United States.

So when you tell  kudzu’s legends, remember to include some stories of those other invasive plants which may be doing more silent damage without the fanfare held by the illustrious kudzu.

Laura Kraft is a Georgia native, having grown up in Alpharetta, Georgia. She is a joint Bachelor’s/Master’s student studying aphid endosymbionts under Dr. Kerry Oliver, looking for a PhD program outside the southeast to move to. When not in lab, you’ll find her at one of a couple Spanish conversation tables around Athens or improving her amateur photography skills. More from Laura Kraft.