I too hate using chemicals on my lawn, landscape, or tropical plants, but I still use Orthene to kill fire ants in my lawn/beds (or any other ant that invades my plants). You can either sprinkle a very small amount onto the soil (or with epiphytes, lightly dusted at the base of the plant) or mix 2 tbl. per quart of water and use it as a drench. Both are effective. I have never seen Orthene harm a single other thing because of the fact that after 24 hours you can flush the pot/plant with water. All the ants will have been killed within that 24 hour period.
