The Pumpkin cemeteries can only be refilled with "Pumpkin refillers". If you're wondering how you can get those precious refillers, you should play adventures: not all of them offer Pumpkin refillers, but most of them do. You can find the complete list in the in-game Event window.
Ok found the "list", but is that really the best "list" you can do?
In my world a list implies at least some kind of sorting, and some values to how many refills each adventure drops would be nice aswell.
Thanks