If you are brave enough to drive around South Carolina with your windows down during fall’s ragweed season, you might catch a whiff of something that smells like grape soda or grape jelly. You might even catch a flash of purple in the sea of green that covers large sections of country and parts of undeveloped city blocks. The green blanket that crawls over anything in its path (trees, tractors, power poles, buildings, shrubs and, I’m guessing, slow-moving people) is kudzu.
On April 28, 1918, my husband’s great-grandfather recorded in his daily journal, “Planted cudzu vine.” Since we now live on the farm that was then his home, I am thankful he was not successful with the plant that was widely touted to stop soil erosion. Erosion was especially troublesome for large tracts of land that were depleted by repeated crops of cotton. Kudzu was first introduced in the US in 1876, at a Centennial Exposition in Philadelphia that was meant to celebrate our nation’s 100th birthday. During the Great Depression, our government created jobs for workers by paying them to plant acres of the vine. There was no way to know that kudzu would be much more vigorous in the southern USA than in its native Japan.
Pueraria montana (known by absolutely everyone as ‘kudzu’) has spread across the entire southeastern US. Some jokingly refer to it as The Vine That Ate The South. Kudzu loves southern heat and humidity but is also found as far north as South Dakota and as far west as Washington state. In hot weather, the vine can grow as much as one foot per day. It thrives in any type of soil and never needs irrigation. It may reach up to 100 feet – in ONE season! It kills trees and shrubs by blocking sunlight. It can also strangle trees by girdling their trunks. Current estimates say that two million American acres are covered in kudzu. It is included on every invasive list. The huge tap roots may produce as many as thirty vines growing from a single crown. Vines also root where they touch soil. The pretty purple flowers resemble pea blossoms and smell like grapes. They mature to flat seed pods.
Control is difficult. Deer don’t seem to care for the fuzzy stems, but goats feed happily. Best results include a combination of herbicides, repeated close mowing, mechanical removal of the root crowns, and prayer. The US Department of Agriculture is investigating biologic controls including a natural fungus.
