servatusprime

I most often dump the contents of a push mower bag in the center of the mat and let it cascade around naturally, spreading out the larger clumps. Sometimes for aesthetic reasons I will spread it out for a more uniform look. Thick or thin doesn't seem to be too critical. I try to keep the material more or less within the "drip line" of the mat.

No idea on the potted plants. I'm would guess that it isn't quite as good. With all the heat, rain, and bugs (worms, millipedes, etc.) the material breaks down. In a room temperature pot it might take a while to break down.