The idea is that the yogurt, milk, and buttermilk can be used to raise the pH level of the soil or growing medium/surface. Moss tends toward the acidic. In this method you are talking about, in which the moss is (usually) dried out, then broken up in a blender, what you are supposed to be creating are, in effect, numerous little cuttings of moss that will re-propagate themselves, eventually merging together into a single mass. The problem is that not all moss is easily propagated from broken-off pieces.

Buttermilk and yogurt are usually suggested, and they both have a low (to very low) pH. That's why they're used for this purpose.

As far as I knew, moss didn't just regenerate from chopped up pieces, but rather grew from spores. Anyone have any information about moss "regenerating?"

Of course, moss propogates itself by means of spores. I am not sure about the moss/yogurt scheme because I have never tried it, but it is undoubtedly the method most well-favored and highly publicized in gardening magazines and newspapers. This I suspect has less to do with its effectiveness and more to do with its novelty (it sounds good and makes a good story), but I could be wrong. I don't know what the biological explanation is for mosses growing back from little dried up fragments. A single patch of moss can consist of thousands, or millions of individual plants, each with its own stems and leaves. Some mosses are equipped to regrow from broken, even highly dessicated fragments because they have adapted to being pulverized by ice and enduring the predations of animals that eat them, and use them to build nests, etc. It makes sense as an adaptive strategy that moss be able to regrow from fragments. This is what the blender/yogurt method attempts to exploit.

Where are you trying to grow the moss?

Depending on what kind of climate you live in, if you're trying to get moss to establish itself on grassless earth, you can prepare the ground by raking it and keeping it free of grass, weeds, leaves, twigs, and debris, and acidiphy the soil with Rhododendron fertilizer, or milk powder to a reading of pH 5.5. This should make the ground an inviting place for spores to settle, and moss to grow and thrive. Otherwise, moss spores can be purchased for bonsai pots, etc. If you are interested in moss cultivation for bonsai, see the link below - it should prove useful. Will Heath, the author of the article linked below, has a recipe for growing small patches of moss that can then be installed in bonsai pots. Otherwise, there are methods for growing moss from little moss sods taken from locally growing mosses.

Here is a link that might be useful: moss basics - bonsai

The link below is an example of one type of moss spore that can be purchased. It is intended for bonsai. I have used this brand, it did work for my bonsai container.

Here is a link that might be useful: moss spores

Hi
Can't tell you a thing about the science of it but it works. You will get at least 3 times the coverage in half the time. In really wet situations will also grow algae which is a downside.Try it you'll be amazed gary

im trying but, only had beer on hand so i just went out and dug under the snow to get some moss then chopped it finely with scissors (as finely as i could) and mixed with beer, now it is smeared on a rock inside. i really hope this works, i definitly want to grow tons of moss