I had a really good phone conversation with Jim from Moss Acres. He confirmed that moss, along with ferns, are a really good air-purifiers. He recommended looking into the Stuttgart moss wall in Germany to glean data from that. Bt he basically said that all moss cleans air.

Jim recommended the using the moss species Bryum Caespiticium for my wall for a number of reasons:

• It grows everywhere on earth
• does really good vertically
• grows faster than other species
• grows in open spaces as well as shaded which means it can take some partial sun

Jim also recommended a could of other species that only do well in full shade but do well growing on hard surfaces:

• Bryum Hypnum 
• Bryum Thiudium (i.e. fern moss/sheet moss)

He recommended staying away from clumping moss and stick to mosses that spread because the clump could get so big and heavy that the rhizoids won’t be strong enough to hod it onto the wall. That said, if I made special tiles with some depth or a shelf to hold the clumps, that could work.

At Moss Acres, they grow their moss indoor under LED lights and they grow moss horizontally and then install it vertically because it is impossible to get moss to attach vertically. They mist 1-2 minutes every hour because the moss dries out fast and need more moisture than you think. Since moss has no roots, the leaves need to be kept moist. They use rainwater to mist the moss because Jim said that was the best. However, he said he saw Bryum Caespiticium growing near a swimming pool which goes to show how resilient that species is. It’s safe to stick to rainwater but tap water won’t be an end-all. To combat mold, Moss Acres actually keeps the substrate dry out once the moss is established and keeps just the moss moist. However, a moist substrate helps the moss spread.

 

What shall I do now??

Jim said that my “starter tile” wall system could work. Recap: that’s my idea of a modular wall where only some of the tiles have moss pregrown on them called “starter tiles”. These starter tiles get inserted into a a wall with no moss on it and the moss on those tiles spread to the other tiles. The starter tile could then be reused to start new walls or they could stay in that wall.

I’m going to call the starter tiles “starters” and the other ones “spreaders”. Also note: I’m playing around with the idea that these tile are actually between a tile and a brick (tilebricks) and that they lock into one another to create a semi-self supporting structure.

So I’m thinking my system will have dry starters with moss established on them inserted into a wall of spreaders that are kept damp to encourage the moss to spread onto them. The spreaders will be dampened by pouring water onto the top of the system and having the water trickle down. The starters will be kept dry by glazing around the edges.

I think these tilebricks are hexagons because the water will flow in the cracks and coat the tile fully. So the spreaders will only have to be kept damp until the moss has fully taken them over and established itself. After that, like the starter, they will be allowed to dry out to combat mold.

Throughout the life of the wall, the moss will have to be constantly misted. I think combining this system with a humidifier that would be good for the moss as well as the user in a dry room. What if the user doesn’t want the humidifier on all year? Because moss is an evergreen and can dry out and remain dormant for a long time, the user could choose to only keep the moss active during the parts of the year when a humidifier is needed.

Also, I would be using moss the spreads instead of clumps (i.e. the types that Jim recommended). Although, some of these tiles could be adapted to hold clumps to add another texture and variety to the wall.