Amusingly, 'Nature Chair' was a commonly used search term for this blog. So let us have another! Very nicely done, actually. Public seating, to convert hard-scape and the dead edge of a wheelchair ramp becomes public seating. The hay bales provide support, and an organic matrix for the grass to grow into. Certainly, they will dissolve over time, but cellulose dissolves slowly, while it's cheap enough to do quickly as almost an experiment.