when making handmade fondant roses for a cake how long before the cake is going to venue or person do i make the roses?

I like to do mine at least a week in advance. That way I know they are good and dry. Also, I use 1/2 fondant and a 1/2 gum paste mix.

You'll want to make them far enough in advance so they can dry out thoroughly and you have time to touch up with some pretty petal dust. If you're doing leaves, I've found if you steam them a bit (maybe the day before you put them on the cake) they look more realistic.