Hi Dawn Marie!
Thanks for writing. I recently moved to Central Florida and love being able to take advantage of the many wonderful seasonal events that the Disney Parks have to offer the International Flower and Garden Festival (taking place on March 7-May 20 this year) is one of my absolute favorites. Disney does, indeed, often offer discounts to passholders on resorts, dining and a variety of special events. These discounts vary and change over time, so the best place to see if any discounts are available for the dates you have in mind is
HERE.
As for the best time to go see the gorgeous blooms and other magnificent displays, including, my favorite, the Butterfly Garden, I recommend going during the week, if possible to avoid weekend crowds. In addition, I prefer to visit after Easter, in early May, when the bulk of the Spring Break crowds have headed home.
Whenever you chose to visit, I hope you have a wonderful trip!