Environment: Amber Waves of Grime

So, if a tree grows in Brooklyn, why not wheat in Manhattan?

New Yorkers with an urge to keep the concrete at bay usually settle for sooty geraniums on a windowsill. Not Agnes Denes, 43, a New York conceptual artist. Her creation, only six blocks from the bustle of the World Trade Center, is a two-acre wheatfield. Shifting and shimmering as the sun and harbor breezes play across it, the minifarm lends an improbable air of Manhattan, Kans., to lower Manhattan.

Last May, Denes with the help of about 60 paid and volunteer assistants, and financed by a $10,000 grant from the Public...