Fire ants find your vegetable garden because you have provided perfect conditions for them – a sunny location with raised, improved soil, and plenty of forage. Fire ants are not a serious crop pest, but they will feed on okra blossoms and pods, red potatoes, and will tend aphids on other plants.
Until recently, there were NO products listed for use in vegetable gardens or around fruit trees. Organic gardeners were reduced to pots of boiling water – a practice we consider dangerous to the gardener, their pets, and small children. One trip at the wrong moment could spell disaster.
The only other option was to use a band of fire ant bait around the perimeter of the garden, counting on foraging ants to carry the bait to the mounds within the vegetable garden. This works, but concerns about baits whose active ingredient is acephate are warranted. Acephate should not be used near ANY edible plant. It is a systemic insecticide that is readily absorbed by the roots and translocated to the leaves and fruits of edible plants – the very parts we are consuming.
Spinosad-based fire ant treatments labeled for use in edible gardens have become available recently. Spinosad is derived from a naturally occurring soil bacterium. The problem is that we have tried several of these, and they do not seem to have much effect on the mounds in a timely manner. They can take two to three weeks to see results. This makes for a dangerous, or at least uncomfortable, environment for the vegetable gardener or hobby orchardist who is often in the edible garden daily.
In addition, spinosad is deadly to bees. It should never be used on blooming plants that are either dependent on bees for pollination, or that are attractive to bees.
The best treatment we have found for eradicating RIFA in an edible garden is the Orange Oil Mound Treatment. You may lose a few earthworms in the process but remember that RIFA feeds on them also. Ridding the edible garden of RIFA will benefit the worm population in the long run.
There are times of the year when RIFA is not ‘mounding’. If ants are a bother in the edible garden, but mounds cannot be located for treatment, apply a band of broadcast bait around the perimeter of the garden and in the paths between beds.
Make sure the product does not contain acephate. Foraging ants will carry the product into the mounds within the edible garden area, but the amount will be quite small and the danger of toxicity will be negligible. This method is a compromise. We avoid it, but we want to offer a practical method for those whose only other option would be to steer clear of their edible gardens when Fire Ants are active.