Wastewater problem? Just plant a marsh: for some of the toughest environmental cleanups, plants can do it better and cheaper than we can. (phytoremediation schemes still experimental)(Column)

For some of the toughest environmental cleanups, plants can do it better and cheaper than we can

No one is suggesting that the plant kingdom isn't doing its fair share. All those leafy creatures are photosynthesizing their virtual hearts out producing the oxygen that keeps the rest of us going. They filter the air, and they prevent erosion by slowing the speed of incoming raindrops and by holding the dirt together with their root systems. Plants provide timber for houses and the furniture that fills them, pulp for paper (a tree died so you could read this column) and flowers for hospital patients. Tens of millions of acres produce the grains that feed our cattle, hogs and chickens.

For ourselves, plants are both sustenance and beauty, in either order. The news is that the plant world can do lots more for us: it can become an industrial partner, one that can clean up our mess.

The concept is known as phytoremediation, phyto being the Greek word for plant. Microbes are already being used to clean up such nasty things as oil spills, under the more general category called bioremediation (Smithsonian, April 1993). Now artificial marshes are being …