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Fire ant mound in a tilled garden.

AUBURN UNIVERSITY, Ala.— Gardeners preparing summer vegetable gardens may find their plots already teeming with life, but not the kind they would like to see. Fire ants are common in yards, flowerbeds, playgrounds and gardens throughout Alabama.

Dr. Fudd Graham, an Alabama Extension entomologist, said there are three approaches 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

Baits

Graham recommends fire ant bait as the main means of controlling these pests. Baits have a tiny amount of active ingredient, placed on a biodegradable carrier particle, as well as a food attractant. These baits should be applied in spring and fall for maximum control.

“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.”

Baits are most effective when they are broadcast across the infested area. This way, it is possible to control the fire ant colonies that you cannot see because their mounds have not been built yet.

If there are only a few nests of concern, Graham, who is also a researcher in the Auburn University Department of Entomology and Plant Pathology, recommends individual mound treatment.

Individual Mound Treatments

As stated on the product labels, each mound should be treated when it is warm outside, but not too hot. It is best to treat in early summer mornings or late evenings. During these times, the ants are closer to the surface of their mounds. Therefore, the treatment is mostly likely to affect the queen ant.

You must kill the queen to control a colony. This may be accomplished in a single application, or it may take two or three. If the queen is not killed, the mound will require additional treatments whether it is a big or small colony.

“Most mound treatments, other than baits, say to water the treatment into the mound. Best results occur using two gallons of water per mound,” Graham said. “For some other mound treatments, sprinkle them on and around the mound according to label directions.”

Fire Ant Control 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.”

Follow the directions on the label for vegetable gardens and fire ant control. Be sure to use control products with vegetables on the label when trying to control fire ants in the vegetable garden. By broadcasting a fire ant bait around—not in—the garden, homeowners can control most fire ant colonies in small gardens. This is helpful since 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 there are for use in vegetable gardens.

More Information

For more information on fire ant control in the garden, visit www.aces.edu.

To learn more about how to enhance your garden and landscape, check out Alabama Extension’s “Gardening in the South” series. You can find the series on iBooks.

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).

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