Hi everyone I wanted to if I should use buttercream icing to put non edible balls to the side if a cake or ganache? Which will stick better even if refrigerated?

I have never used ganache but have heard it is great for adhering or stabilizing cake. When making sculptured cakes ganache is used to hold parts together.   Second choice would be b’cream. 

I don’t know — too many variables — but you can use a popsicle stick inserted into the side of the cake to set the ball onto — cover it with a dab of icing — that combination will hold it  —