Moss doesn’t withstand heavy foot or car traffic Where it appears inadvertently reveals which areas are programmatically active and which are not.
As colonies of spores, mosses get most of their nutrients from the air and therefore don’t require soil — just plenty of moisture, which we have in abundance during the winter. Surfaces that convey or pool moisture (such as concrete) are ideal growing surfaces for them. In the drier summer months the moss shrink back like desiccated sponges, turning to more subtle dark greys and browns until the rains return. Because mosses are dependent on air for sustenance, they are susceptible to airborne pollution and serve as an indicator of air quality (Portland seems to be doing well).
Spongy terrestrial reefs
At a time of year when everything appears pretty grey and muted, they form amazing mosaics of color. A ready-made, unintended vegitecture that colonizes the city.
Seems to me that there is a lot of untapped design potential with this material.
(All images taken in Portland. More photos here)