"Beginning in April, vendors from around the world begin receiving orders for flowers to be delivered prior to the completion of the float in late December. One float may require between 400 and 500 varieties of flowers
and millions of individual blooms. Many are specially grown to meet the needs of the float they will be used on. Flowers must be ready to go and delivered within a one-week window prior to the parade, with some arriving the morning of the parade."
-Groupon.com
This article didn't list any numbers other than varieties.
