I am making a wedding cake and the bride's mother wants flowers on branches (fairly thick branches) cascading down the cake. She wants a buttercream cake. I live in South GA, and it's already 90 degrees and humid here during the day, so using modeling chocolate isn't an option. Can I make the branches out of fondant and glue the flowers to it. I am just concerned how I will make the fondant branches stick to the buttercream. Any suggestions would be so appreciated.
Use fondant or gumpaste - gumpaste dries harder and allows for more finer petals and twigs, as it is stronger. Gumpaste/fondant flowers glue perfectly to gumpaste/fondant branches with water or sugar glue.
If the branches can touch the cake/board below for extra stability, that is great. If the branch is still too heavy, perhaps insert toothpicks/cocktail sticks into the back of the branch before inserting straight into the cake horizontally. Remember to tell the venue/cake cutter to remove all the toothpicks before serving to the guest.
I just made a similar cake with branches made out of floral wire wrapped in floral tape. You might consider that method.