
My mother did the flowers for my wedding as well and reported the same thing. In fact, she ended up enrolling my grandmother and cousin to help her set up the flowers on the chuppah and lots of friends had to help out with the rehearsal dinner and reception set up. I think the experience is best depicted with the picture I have of my mother literally pulling her hair out (which I cannot show here out of respect to her).
So what is the lesson? Enroll EXTRA help if you plan to do your own flowers. You can always let your friends head back to change early and you will not leave anyone pulling their hair.