Sporadic Green Fields

In the dark winter months, Portland and the Pacific Northwest are overtaken by moss colonies.  As soon as the long, drawn-out rains begin in the fall, they spontaneously emerge just about everywhere:

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)

In the summer months when the Northwest dries out, the mosses adapt by shrinking back and going dormant.  The luminous greens are replaced by more subtle dessicated browns and greys.


  1. Totally. Copper and iron patinas often make the most fascinating patterns on buildings, ornate or not. The elements of chance and chaos are in play beautifully.

    Unfortunately, moss-based green walls might be limited to wetter climates.

  2. http://www.mossacres.com/default.asp

    Moss Acres is a well known moss grower in the northeast. They are definitely a good resource to consult and use if you intended to use moss in any project.

  3. …limited to wetter climates…
    Indeed, and lichens in drier places. But in the Pacific Northwest where it grows in abundance without a choice, we could find ways of incorporating it more strategically as a vegetated surface–like greenroofs. It seems we could design better roof surfaces that produce super-dense moss coverings for stormwater absorption without damaging the roof material, and to avoid the need for the standard growing medium that other plants require. I’ve seen some other studies that have successfully used the moss as the starter medium for greenroofs.

  4. namhenderson · ·

    I was actually just noting on my way into work today how the Spanish Moss (I am in FL) has colonized the walls of the parking garage making little micro ecologies of moss plateaus

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