The best of intentions sometimes go astray. Take kudzu, for example — the vine that ate the South was brought here in the 1930s with the aim of curbing the soil erosion that was washing away much of the landscape. The USDA actually paid farmers to plant the stuff.

It was (and continues to be) an example of a cure being worse than the disease.

Kudzu — which can grow a foot or more overnight — found our hot, humid climate much to its liking, swallowing not only eroded gullies, but fields, trees, power poles, and almost anything that stood still for very long.

The list of invasive species, both introduced and accidental, that have found a home in the U.S. is long: cogongrass, Chinese tallow trees, privet, are among the South’s more notorious and difficult to control. Many older farmers still have nightmares of the thorn-laden multiflora roses, which were once planted as “a natural fence,” but spread like crazy.

While the USDA has inspection programs and other measures aimed at stopping invasive species from entering the country, it’s like trying to halt a bulldozer with a fly swatter — there are just too many opportunities for something to slip through.

It’s estimated that invasive species cost the U.S. $120 billion each year.

Now, a number of organizations are concerned that another good intention, in the form of a plant proposed as a biofuel feedstock, could be the source of future regret.

The Environmental Protection Agency is currently in the final stages of approving a rule that would provide incentives for companies to plant certain invasive species for biofuels production.

One, giant reed grass (Arundo donax), a clumping cane-like plant that can grow 30 feet tall, is on the World’s 100 Worst Invasive Species list, and while proponents describe it as “possibly the finest bioengery crop available,” a number of groups and organizations are concerned that planting it widely could be a recipe for disaster should it escape cultivated areas.

Among opponents, the National Wildlife Federation says Arundo will crowd out native plants, form dense monocultures along rivers and streams, threatening ecosystems and the animal species that depend on the original plant life. Control costs, NWF says, can range from $5,000 per acre to as much as $25,000. Those promoting it say it can be easily controlled with two diskings annually around field borders.

In Alabama, where the plant is a widespread problem, the state’s Invasive Plant Council says “the large planting … would present an incalculable risk to the people and ecosystems … (with) potential for irreparable damage to the state’s natural ecosystems, which provide vital ecological benefits to the present and future citizens …”

Representatives of more than 100 local, state, regional, and national groups and universities have signed a letter to the USDA, EPA, and Departments of Energy, Defense, and Transportation, urging “a thoughtful, consistent, proactive approach to sustainable bioenergy production that avoids potentially invasive feedstocks.”