I'm a brand new martha subscriber and can't seem to get to the other comment pages, so maybe this hint is already somewhere else. I read if you scrape moss off something, blend it with water, then pour mixture over what you want to look mossy, the moss spores will start growing there. Haven't tried yet but will.

I have tried this technique over and over and it really doesn't work. Moss happens where moss happens.
To "age" new terra cotta pots quickly, simply pounce on some watered-down green paint, then go over it with a water-wet paintbrush to blend the paint. After this dries, brush on a mixture of horticultural lime and water. When this dries, rub it haphazardly with a damp cloth and leave the pots outside for rain to do the rest.
An hour after I started, my pots looked ancient!

Earth is plain old garden soil--what else. There's nothing fancy about it.

Nancy D. If you have a problem with Martha's wonderful informative ideas, then move on to another website. Rudeness does become you!

Great idea! I am going use some old pots I have and the moss that grows out ion the earth below some trees in the back yard.

I tried this once and it didn't work. Any suggestions? What about a darker ,damper environment?