Picture posting is enabled for all :)
If you put something light at the bottom of the pot, will it make it top heavy so it falls over?
PS. papier mache is exactly the kind of thing you do want on top of your beds as a sheet mulch - better than plastic because in sunshine plastic doesn't last much longer, and it turns into dust and shredded flakes that will still be looking awful after you've passed beyond seeing them. Shreddings under ripening strawberries are a cushion that turns into a sheet mulch for the rest of the year.