The kudzu vine has become the poster child for invasive species. Native to Asia, the vine was introduced to the US in the 1870s and widely used for erosion control. Fast-growing and resilient, it decimates local flora and is extremely difficult to kill. It is especially widespread in the southeastern US.
Kudzu does have its good points. It really is very effective at anchoring the soil and preventing erosion. Its taproots draw minerals from deep in the ground to the topsoil, and it also increases nitrogen content of the soil. Animals can graze on it, and it has some potential medical uses as well. All these are overshadowed, though, by its rapid growth and tendency to take over, making it an unwanted guest that just can’t be gotten rid of.
There have been many attempts at killing it, but most are expensive, labor-intensive, or ineffective over the long term. Fire is not very effective; some herbicides are, but their widespread use is expensive and undesirable for other reasons. Cutting and mowing temporarily remove it, but it grows back quickly. Removing the crown—the part of the plant directly above the root—is more effective, and if the whole crown is successfully removed the plant dies. However, if a crown is planted again, an entire plant can grow from it. A good part of the plant’s rapid spread throughout the Southeast is thought to have resulted from disposal of the cut biomass containing viable crowns.
There may be a new tactic, though, more effective than most and with fewer unwanted side effects than fire or herbicides. A 17-year-old from Georgia, expanding on what originally began as a sixth-grade science project, is successfully using helium to kill kudzu. Jacob Schindler has invented and patented a drill that delivers helium into the root system. (Other gases he administered this way, such as carbon dioxide, proved ineffective.) He is currently working with Auburn University to test the method over large areas.