Lead-absorbing tropical grass withstands N.J. winter

    A New Jersey researcher is hoping a common subtropical grass could soon be removing lead from backyards across the Garden State.

    The grass vetiver is what Montclair State University environmental studies professor Dibyendu Sarkar calls a hyper-accumulator — it sucks lots of heavy metals out of the soil.

    Sarkar’s previous studies showed vetiver could remove enough lead from moderately contaminated soil to bring it within EPA limits in eight growing cycles. That is eight years in New Jersey, fewer in warmer parts of the country.

    This winter, his goal was to see if the subtropical plant could survive here.

    “The planter boxes are all outside, and the plants did not die … it survived,” Sarkar said, with some surprise.

    Sarkar will follow up this small study with large-scale testing in brownfield sites, to see if the grass will thrive in more natural conditions.

    Dick Grimshaw, founder of the Vetiver Network International, said he thinks heavy mulching would be required for the plant to survive a typical New Jersey winter. That effort, and the need to pull up the grasses periodically to remove the lead from the environment entirely, would make it impractical for most homeowners, Grimshaw said.

    “There are two aspects of science,” Grimshaw said. “One is showing what the theory is, and then you have to see whether you can actually put it into practice — and if it’s something which the users are going to do.”

    The grass is common in tropical and subtropical areas and has been planted for years to prevent erosion and runoff.

    More recently, it has been used in former industrial sites in China, Vietnam and Australia to remove heavy metals such as arsenic from the soil.

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