SAN ANTONIO – The KSAT garden officially has been invaded, by fire ants.
“The ant mounds that pop up are most likely going to be fire ants,” Molly Keck, an entomologist with Texas A&M AgriLife Extension Service of Bexar County said. “Here, we have over probably close to 100 species advanced in Texas. So not every ant is going to be a fire ant, but most of them are.”
Keck confirmed the ones in KSAT’s garden are fire ants.
Keck said we are not alone, as fire ants tend to pop up all over South Texas after a big rain.
“When the moisture gets down into their mound, they’re going to push up above so that they don’t drown,” Keck said. “So after a rain event, that’s when you see the mound show up.”
Keck said you can identify fire ants by simple things.
“Fire ants are the only ones that make that above ground, pillowy, fluffy mound,” Keck said. “They have no single entrance, so when you mess with them, they come out from everywhere.”
So what is the most environmentally friendly, organic and effective way to get rid of them?
Remember you don’t want to use harmful or synthetic pesticides, because pesticides kill all bugs, including vital pollinators. A good go-to organic pest treatment is usually diatomaceous earth.
Keck said in our case, it won’t work, in knocking out the fire ants.
Because the soil is so moist from the rain, plus since the garden is watered weekly, the diatomaceous earth powder will lose effectiveness.
Boiling water is sometimes an option.
Keck said that can work if your ant pile isn’t near your plants, because that hot water can destroy the plant’s roots.
In KSAT’s case, the mound is basically on top of the milkweed.
Another safe method is dish soap, but she said fire ant colonies can go several feet into the ground, so it won’t knock them out permanently, just the ones you see at the top of the mound.
“They can go deep, six feet deep, they’re also very fluid,” Keck said. “So they can kind of spread out. They have little kind of pockets within their mound. It’s what you see as the tip of the iceberg. And what’s below is really expansive. And if you think about it, you wonder what happened. Why does that mound pop up between my sidewalk and my, you know, my grass or my lawn? Well, it was probably under the sidewalk or under the driveway where it was cooler and there was more moisture.”
Other organic options can include neem oil, Keck said, similar to dish soap. This won’t be a permanent fix because it needs to go several feet into the ground.
Orange oil is also used as an organic pest option for fire ants, but it can also kill your plants.
Keck said in KSAT’s garden, the best bet is using an organic bait with Spinosad.
A good example of this is organic Fertilome’s “Come and Get it” which can be found at Walmart, Amazon or at a local nursery.
She said to sprinkle the bait all around the soil (not on the plant) and keep it dry for the day.
“They’re corn grit soaked in soybean oil, which they’re attracted to,” Keck said. “They like protein and greasy stuff. And then it’s also soaked in the pesticide. So they take that out of the environment. They carry it into the nest. They feed it to the queens and to their babies.”
My biggest concern: will this hurt the pollinators? The main reason for the garden.
I always almost never use any pest control methods if I don’t have to. Keck said if these were native ants, leave them alone.
Native ants are beneficial and aerate soil. She said not only do fire ants have a vicious sting, if left alone in the garden, the fire ants would end up hurting the pollinators.
“Those fire ants are going to predate upon those monarchs and those other pollinators, for sure,” Keck said. “So you’re killing them if you’re not killing your fire ants. And two, hopefully what you’re using, you’re applying it to the soil. You’re not putting it on the plant material because that’s not where that is mounting. So apply it in the right place, using the right thing and being smart and not allowing it to drift on to the flowers or onto the leaf material. And that will that will salvage your pollinators.”