The myth of kudzu has indeed swallowed the South, but the actual vine’s grip is far more tenuous.
In news media and scientific accounts and on some government websites, kudzu is typically said to cover seven million to nine million acres across the United States. But scientists reassessing kudzu’s spread have found that it’s nothing like that. In the latest careful sampling, the U.S. Forest Service reports that kudzu occupies, to some degree, about 227,000 acres of forestland, an area about the size of a small county and about one-sixth the size of Atlanta. That’s about one-tenth of 1 percent of the South’s 200 million acres of forest. By way of comparison, the same report estimates that Asian privet had invaded some 3.2 million acres—14 times kudzu’s territory. Invasive roses had covered more than three times as much forestland as kudzu.
And though many sources continue to repeat the unsupported claim that kudzu is spreading at the rate of 150,000 acres a year—an area larger than most major American cities—the Forest Service expects an increase of no more than 2,500 acres a year.
The hype didn’t come out of nowhere. Kudzu has appeared larger than life because it’s most aggressive when planted along road cuts and railroad embankments—habitats that became front and center in the age of the automobile. As trees grew in the cleared lands near roadsides, kudzu rose with them. It appeared not to stop because there were no grazers to eat it back. But, in fact, it rarely penetrates deeply into a forest; it climbs well only in sunny areas on the forest edge and suffers in shade.
Still, along Southern roads, the blankets of untouched kudzu create famous spectacles. Bored children traveling rural highways insist their parents wake them when they near the green kudzu monsters stalking the roadside. “If you based it on what you saw on the road, you’d say, dang, this is everywhere,” said Nancy Loewenstein, an invasive plants specialist with Auburn University. Though “not terribly worried” about the threat of kudzu, Loewenstein calls it “a good poster child” for the impact of invasive species precisely because it has been so visible to so many.