Golden rod, Buckwheat..Anything that can flower late in the year is going to be good for the bees. I don't know much about what blooms when in Florida. I assume you have a dearth period? You might find buckwheat on-line. I get my seed from Amish country in Ohio. I guess in FL you could plant it all year long.
I use it for winterization. Many make honey out of it. Be warned, buckwheat honey tastes a lot like Black Strap Molasses, but with a metallic aftertaste. Some of us love it. Others hate it. Bees like it plenty though!