Garden ant control requires vigilence

As passionate as Franklin Countians are about spring gardening, fire ants have an even stronger desire to make those vegetable patches their home.

“Ants damage some vegetables, especially okra and Irish potatoes, but they also damage gardeners,” Dr. Blake Layton Jr., a Mississippi State University Extension Service entomology professor, said.

“Gardeners who unknowingly step in mounds can quickly be stung dozens, or even hundreds, of times.”

Layton said fire ants are the most common variety of pests in Mississippi, and the best way to keep them out of your vegetable garden is to do a good job of controlling them in your lawn — especially any areas immediately outside the garden.

“Granular baits work well for this purpose, but, keep in mind, most of the fire ant baits used in home lawns are not approved for use directly in vegetable gardens,” he continued.

He recommended applying a labeled fire ant bait to a 50- to 75-foot wide band around the outside of your garden two to three times per year — in the spring, mid-summer and fall.

“You will have a lot fewer problems with fire ants in your garden when you do this,” Layton added.

“Just remember, baits are slow-acting and have to be used preventively.”

There are usually fewer fire ant mounds in tilled areas, such as gardens and fields, because tilling disturbs the ants and causes them to move.

But, Layton noted, there will be some mounds that persist, despite being disturbed by tillage.

“Some fire ant baits can be used in the garden and lawn — specifically baits containing the active ingredients methoprene (Extinguish is an example) or spinosad (Greenlight Fire Ant Bait with Conserve and Safer Fire Ant Bait are examples), and both these products are even approved for organic garden production,” he said.

“Baits containing spinosad are relatively fast-acting and this makes them a good choice for controlling mounds that occur in the garden itself, but it will still take two or three weeks to see results.

“Don’t wait until you have big mounds, go ahead and apply one of these baits as soon as you see fire ants moving into the garden. But don’t forget to treat the lawn area around the outside of the garden, as well.

“Workers from mounds located just outside the garden will readily forage into your garden area.”

Layton pointed out gardeners can also use a liquid drench to eliminate large mounds that need to be controlled quickly, but be sure to only use an insecticide labeled for use in home vegetable gardens.

“Many insecticides commonly used in home vegetables include label directions for mixing and applying as a mound drench,” he continued.

“Products containing the active ingredients spinosad, permethrin or carbaryl are quite effective as mound drenches and are often used to control other pests in the home vegetable garden.

“Use a watering can, or similar container, to mix and apply the drench. Just read the label, mix the specified amount of insecticide in water, and pour over the mound. The key to success with liquid drenches is to use enough liquid to thoroughly soak the mound.

“Depending on the size of the mound, this ranges from one to two gallons. Begin by applying about ¼ of the total volume to a 10- to 12-inch band around the outside of the mound.

“This prevents the queen from escaping through underground foraging tunnels and improves control of workers.

“Then apply the rest of the drench directly to the mound. Liquid drenches are time consuming to mix and apply, but when applied properly they will eliminate a mound within a few hours.”

Layton urged vegetable gardeners to never use mound treatments containing the active ingredient acephate — an example of this is Ortho Fire Ant Killer.

“Acephate, which is either colorless or in white crystal form or powder and smells like rotten cabbage, is commonly used to treat fire ant mounds in home lawns, but it must not be used around edible plants,” he said.

“Acephate is a systemic insecticide that is readily absorbed by plant roots and translocated to leaves and fruit of vegetables.”

Layton further recommended gardeners download MSU Extension Publication No. 2347, “Insect Pests of the Home Vegetable Garden,” for recommendations on control of most garden insects.

This and other gardening information can be found online at www.extension.msstate.edu.

Additionally, gardening information is also available at the MSU Extension Service office at 20 Walnut Street in Meadville (across the street from the Franklin County Courthouse) or by calling 601-384-2349.