A subtropical plant native to India and other warm countries may be the solution to the removal of soil contaminants like lead. Vetiver is in the sorghum family but has some of the same characteristics as lemongrass, and greenhouse tests in New Jersey indicate that it is exceptionally good at absorbing lead from soil and storing it in its tissues.
Researchers from Thailand, India and China have studied vetiver’s ability to absorb heavy metals, and it matches the results from the New Jersey lab. Companies now plant the non-invasive species on landfills to reduce contamination, and in California it is being used to filter out contaminants from parking lot rainwater runoff.
Vetiver grass has been used for years to prevent soil erosion. The shoots of the tropical grass reach three to six feet tall, and the roots can extend much deeper.
Plants are being used more often to clean soil and water of many kinds of contamination, a process known as phytoremediation. Chinese brake fern, for example, can absorb arsenic from the ground, and mustard plants have been used to remove other heavy metals.
While the grass may not be hardy enough to survive in northern climes, it has been seen to flourish in the south and in California.