AUBURN, Ala.—Homeowners breaking ground in gardens this spring may find the plot is teeming with life coming out of the winter season—a different kind of life than they would like to see. Fire ants are common in yards, flowerbeds, playgrounds and gardens throughout Alabama.
Dr. Fudd Graham, an Alabama Cooperative Extension System entomologist, said the following are three approaches that are used to control fire ants in the lawn and garden.
- Treating individual mounds with a bait or contact insecticide
- Broadcasting a fire ant bait that the ants pick up and take back to the nest and feed to the queen
- Broadcasting a long residual insecticide across the area that will kill smaller colonies and prevent new colonies for a period of time
Control In and Around the Garden
Graham, who is also a researcher in the Auburn University Department of Entomology and Plant Pathology, recommends fire ant bait as the main means of fire ant control. Baits have a tiny amount of active ingredient placed on a biodegradable carrier particle along with a food attractant. For maximum control, baits should be applied in spring and fall.
“Baits are relatively inexpensive and are environmentally sound,” Graham said. “The fire ants in the area generally pick up most of the bait particles in a short period of time, meaning there is minimal impact on non-pest ants.”
If there are only a few nests to worry about, Graham recommends the individual mound treatment option.
Read the Label
In compliance with the product label, each mound should be treated when it is warm outside, but not too hot. In the winter, this means treatments during the middle of the day. During the summer, it is best to treat in early morning or late evening. These times are when the ants are closer to the surface and therefore, the mound treatment is most likely to affect the queen.
In order to control a colony, you have to kill the queen(s). It may take one application, or it may take two or three. Follow the directions on the label for vegetable gardens and for fire ant control. Whether it is a big or small colony the queen must be killed, otherwise the mound will require additional treatments.
“Most mound treatments, other than baits, say to water the treatment into the mound,” Graham said. “Best results occur using two gallons of water per mound.” On the other hand, sprinkle certain dusts on and around the mound according to label directions.
Controlling Fire Ants in Vegetable Gardens
Fire ants are like humans: they eat many different foods. Gardeners may see ants crawling on leaves, flowers and fruits in the garden.
“Fire ants search for fats, proteins and sugars. They come to plants to feed on nectar in flowers and extrafloral nectaries,” Graham said. “They also protect aphids on plants because the fire ants feed on the aphid excrement, honeydew. Fire ants also feed on seeds and on other insects.”
When controlling fire ants in the vegetable garden, be sure to use control products that have vegetables on the label. Homeowners can control most fire ant colonies in small gardens by broadcasting a fire ant bait around, but not in the garden. This is helpful if you baits labeled for fire ants in vegetable gardens are difficult to find. There are more fire ant baits that are legal to use in home lawns and other grassy areas than in vegetable gardens.
For more information on fire ant control in the garden, visit www.aces.edu. There is also a fire ant control webinar recording by Dr. Jason Oliver, part of the All Bugs Good and Bad webinar series presented by eXtension.
Based on proven Master Gardener training and seasoned with university research, the “Gardening in the South” series of books is packed with information, tips and tricks to being a successful Southern gardener.
Have a gardening question? Call the Master Gardener Helpline. To reach the helpline, dial 1-877-252-GROW (4769).