I agree with anon.  The shoveling of dirt into an open grave is one of the most meaningful D+D rituals I know. One is certainly forced to come to grips with the fact that a loved one is underneath.

The symbolism of rocks perched atop gravestones, however makes me a tad uncomfortable.  It smacks vaguely of superstition, which, depending on the historical narrative you choose to believe, can either come from the permanence of stone (compared to flowers) to the calling card account to the keeping of the dead in their place.  

By the way, I also wanted to note - I have an Evil Grandma B (EGB) so I completely relate to the EDM acronym.

Thanks for this article - lovely.