Moss-facilitating sculpture with integral wormbin

Shaded garden sculptures are often intended to become mossy. But this is hard: the moss must show up, latch on and somehow thrive in a dry and fertilizer free environment. Even after many years, some statues just have a faint jaundice rather than a verdant mossy coat. Martha Stewart catalyzes the process by daubing on a mix of buttermilk and chopped up moss but this seems like cheating - and plus I skeptical about the durability of such artificially established mosses.

I propose that a porous statue constructed with an overlying worm bin would allow nutrient rich worm tea to percolate down thru it, thus facilitating and nourishing the moss, algae and other hangers-on. The statues could be caryatids, green men, gnomes or whatever other garden denizens you fancy, each with an urnlike worm bin atop.