My cats won't stand on or move the pine cones because the cones are "stickery" to their paws. The fresher the pine cones, the better they work. I tried cypress mulch, rocks, citrus peels, and cat deterrent spray, which stinks by itself, but the cats still used the pots, even though they have four regular litterboxes and a Littermaid handy. When our youngest cat started to remove cones last winter so he could bat them around, I added the stakes to make removal more difficult. So far it's working, and I am not constantly having to dig out and replace soil to be able to stand having the ficus and satsuma trees in the sunroom.
