I am making an anniversary cake for a co-worker and convinced her to use real flowers (instead of the all gumpaste that she originally wanted). What do I need to treat them with so that there are no issues with them being sanitary.
Thanks for your advice.

Just make sure they are clean. If they are from a garden wash and dry them carefully and make sure there are no bugs. The flower usually only lies on the cake and doesn't contaminate it. Check the internet for edible flowers so you don't use poisonous flowers.