hi there, wondering what the best way to get ruffle roses made from buttercream (used an all shortening recipe) to adhere to a cake? Should the cake be iced with the same buttercream? I tried this and overnight they slipped down the cake :( thank you, thank you!

I was also thinking to do a thin layer of royal icing prior to piping the roses?? 

I have always put an open circle of b'cream on the back of the rose before pushing it onto the cake.

You can just use a squirt of icing, but the open circle (I usually pipe i t w/tip 3) helps create a bit of suction to help hold the weight of the rose.

It also depends on how big your rose it.  I prefered to use air-drying b'cream and let them dry at least overnight.  Those can be kept for up to a month in a covered cardboard box or cake box.  NOT in an air-tight container.

Thanks, could the roses be piped directly onto the cake or do they have to be made seperately then placed?