There are somewhere around 700 moss species native to the PNW so any accurate identification is best left to a bryophytologist :-)

Ha. That makes sense. I was mostly wondering how to propagate it, instead of just waiting for it to volunteer, and maybe a bit about it's growth habits and what kind of soil, sun, etc. it likes.

I did a little reading and I'm guessing maybe it's a cushion moss? I only have small pieces though so it's a bit hard to tell.

I've had moss volunteer in my pots before but I think this is the first time I've seen this nice cushy one. I'd actually weeded it out of the pots, and then I realized how handy it could be so I dug back through the bag this morning and pulled out what I could find. If I'd thought of it earlier I could have had a good deal more. Oh well.

For now I've just plonked a chunk or two into each pot and given it some space. With luck it will expand to fill the pot.

Mosses reproduce on surfaces that have a lingering or recurring film of water on them. Hence their prevalence on firm substrates such as boulders, logs and live tree trunks.

As well as potting soil that has become compacted enough on top to support their presence.

Popular wisdom suggests, put clump of moss in blender with some buttermilk. Process. Spread slurry over surface you want to moss cover. Keep dampish...

Thanks everyone!

I've seen the blender suggestion. Does that work with cushion mosses? I've mostly seen it used to get moss to grow on walls and rocks.

I have no idea...just repeating what I'd read. I like mosses, but never encouraged them in any way but keeping weeds down.