Sometimes dubbed “The Vine That Ate the South”, kudzu has an unenviable reputation as the prime example of a runaway invasive species. First introduced into the United States in the late 1870s, the kudzu became popular for its rapid growth and fresh, grape-like scent.
During the summer, under ideal conditions, kudzu can grow as much as 30 cm a day. Over the course of year, it can grow 30 meters or more. It requires no pesticides, fertilizer or herbicides, and indeed seems immune to most herbicides itself.
For the next several decades, kudzu was actively cultivated, and found a variety of uses. It seemed like a wonder-plant. Early uses included being used to shade porches, where its rapid growth and sweet smell put it much in demand. Later uses included being planted in roadside ditches and fallow fields as erosion control. There, again, its rapid growth and tenacious nature made it valuable. It provided forage for goats, and in Asia, where it is native, it finds its way into various foods and traditional medicines.
However, this rapid growth and sheer tenaciousness became its downfall. The southern United States has perfect conditions for this plant, and no predators to keep it in check. Left untended, it can rapidly take over a field, or a forest. One anecdote is that people in the deep south keep their windows closed at night to keep out the kudzu. Kudzu has spread into about 20,000 square kilometers of land in the United States and costs around $500 million annually in lost cropland and control costs.
While kudzu still has its uses, including decontaminating soil, animal feeds, and numerous food uses, its rapid growth led to it being declared a pest species in the 1950s, and the poster child for invasive species.
What might turn things around for kudzu however, could be in the field of biofuels. Currently, biofuels are typically made from corn, which takes this food crop out of its vital task of feeding people. Couple this with the pesticides and herbicides required to grow corn, and using it for biofuels becomes less and less sustainable. Kudzu, however, requires little or no pesticides and herbicides. Little save goats will eat the stuff, in fact, at least on the ground. More importantly, though, the biofuel yield for kudzu is roughly on par with corn, for less work, less money, and less guilt. Kudzu can also grow on much more marginal land (like cliffs and embankments), leaving prime land available for food production.
Left untended, kudzu will grow riot. However, by attaching a value to it, especially in today’s world that is desperately seeking an alternative to petroleum and its attendant demons, kudzu becomes worthwhile to tend properly, to harvest and control. Perhaps by putting kudzu to use as a commodity, people will have the impetus to bring kudzu under control. Perhaps the “cancer of the vegetative world” can help us work to eliminate fossil fuels, while keeping our fields producing food for the hungry of the world.