check this link

Here is a link that might be useful: growing moss on concrete etc

Thanks terrestial, my main concern was the alkalininty of the cement. In digging around a little I find that 5 to 5.5 is considered ideal for moss. This is a little acid which is the ph of my soil which I have tested. The block is 7+ feet in diameter and was dumped (without my knowledge) on my property many years ago by someone unknown. It seems it was formed by pouring concrete into a dished out hole in the ground (???) I have recently cut the trees in this area and when I discovered this lying on it's side on a mound of dirt, I dug out alongside it and wedged it over, falt side down. It now actually looks like a faux "puddingstone" rock and along with some plantings in the area I wanted to "dress up" the "rock".

I am rattling on and the only way I can find out how well or if it will grow at all is to try it. I appreciate the link and will follow the recipe and hopefully have a "crop" by next fall or so. Otherwise some vines will help with the camouflage...maybe not a bad idea to try both approaches at the same time.

In my research I did find a way to help with the existing moss that seems like a good idea. Someone said to sprinkle the insides of a baby diaper over the area. This powder is modified corn starch whis is a super-absorbent which would hold moisture just as the granules they sell for container gardening. It won't work on my rock, but I am going to try it on some of the moss. I don't think it can hurt.