I haven't seen any plant arrangements in toilet bowls around here, but I've seen a lot of arrangements where the pot is sitting on its side and the plants are planted to mimic them spilling out of the pot. Seems to be a trend that started several years ago or maybe even longer ago than that. I have an area where I created a small fairy garden and nearby I have a Plow & Hearth (from QVC) solar light mobile of 6-7 fairies hanging from a shepherd's hook and it color morphs at night. I have to say, I just love seeing those fairies floating around and color morphing from my kitchen window! It's funny the little silly things that can make you smile.
I haven't had any luck with the Knockout Roses, luckily hydrangeas are another story, but I love roses and try as I might, I just don't seem to have luck with them so I usually wind up replacing them with another hydrangea and I'm happy! - hah!