How do you attach dried flowers into a shadowbox?

I have dried whole roses from my mothers funeral and would like to make a memorial in a glass shadow box, but I am not sure how to attach the very delicate flowers to the cloth covered cardboard backing?|||Why don`t you try some florists foam..it`s really cheap..and you can insert the flowers where u want...spray flowers with a light covering of hair spray to preserve longer.|||a hot glue gun will work great