How long will a royal icing drop flower last if attached to a cake iced in buttercream?

I need to deliver the cake tomorrow at 4pm for a Saturday birthday party. If I put the RI flowers on the cake tonight, will they last until Saturday? Or will the fat in the buttercream destroy the RI?

Thanks,
Casey

I've done this with RI roses and they were fine, although they are thicker than a drop flower.

Hopefully someone will see this that has had the exact situation as yours. Sorry, I couldn't be more helpful.

Hi Casey - The bc won't destroy the drop flower, unless it's a very "wet" icing, or you attach them with a very "wet" icing. For instance, I've never had a problem putting them on my crusting bc cakes. I do it all the time. But... be careful if you're attaching them with a dark green bc for leaves and vines... your flowers will soak the color up and can look bad. I either attach them with the same color as the flower, or I attach them with royal icing. Buttercream won't make them melt, it'll just make them soft and can make them "darker" where the softer icing has soaked into them. Good luck!