There are tiny, solid, poisonous pellet that you can sprinkle around your flower bed. The workers will take it down to the colony and poison the colony.
The easiest and quickest way to get rid of fire ants from a flower bed is to go to any local hardware or gardening store. In the gardening section they will sell a powder that you can put down to get rid of the fire ants and it will in no way harm the flowers.
Get fire ant bait that specifically states it will kill the all the ants including the queen. Find the fire ant mound, spread the granules on and around the mound.
They have special kinds of sprays that kill fire ants at garden stores , but they do not have anything in it that will kill the flowers that are in your garden.
