How the #@!*% do I get rid of fire ants in my vegetable garden without using heavy-duty chemical pesticides? Are there any home remedies that work?
Shelve the grits, baking soda, club soda, vinegar, molasses, plaster of Paris, aspartame, cayenne pepper, cinnamon and coffee grounds! In scientific testing, none of these home remedies worked worth a lick against the red imported fire ant (Solenopsis invicta) — a nasty, non-native species that’s invaded the South, from Florida to Texas, and is expected to spread westward into California.
Although most ant species are neutral or even beneficial, this one can ruin a garden in no time by devouring germinating seeds, tunneling into potatoes and tomatoes, and girdling young fruit trees — and they’ll bite and sting you, too. Drought makes these ants even more voracious, as it prompts them to turn to garden crops for moisture.
If you have just one or two fire ant mounds in your garden or landscape and not a widespread problem, you can do a couple of things. The simplest is to pour 3 gallons of very hot water directly onto the ant mound. This method achieves only about 60 percent control, so you’ll likely have to repeat applications often. Be careful not to splash the surrounding plants or yourself.
For an even more effective way to get rid of fire ants, drench the mounds with a citrus oil and soap solution, a combination that’s repeatedly proved effective. In controlled studies conducted by Texas A&M University entomologists, fire ant mounds still showed no activity nearly a month after the researchers had drenched the mounds with a mixture of 1 1⁄2 ounces of Medina Orange Oil, 3 ounces of Dawn liquid soap and 1 gallon of water. A compound in citrus oil, d-limonene, breaks down the ants’ exoskeletons and causes them to suffocate. The commercial product Orange Guard Fire Ant Killer — approved for use in organic agriculture by the Organic Materials Review Institute (OMRI) — also contains orange oil. (For other approved products, check the OMRI website.)
If your fire ant problem is more extensive than a mound or two, step up your response with the “Texas Two-Step” method recommended by Texas A&M University extension specialists for fire ant control in home vegetable gardens and landscapes.
Step 1: Once or twice a year, broadcast a fire ant bait product that contains spinosad — a natural metabolite produced by a soil microorganism — as its active ingredient. Foraging ants will carry the spinosad granules back to their nest, and the granules will kill the colony within a few days to a few weeks. For best results, apply fresh granules when ants are active (when the soil temperature is between 70 and 95 degrees Fahrenheit) and rain is not in the forecast. Conserve Fire Ant Bait is a spinosad product approved for organic use by OMRI.
Step 2: If you spot new fire ant activity in your garden or a surrounding area between applications of Step 1, treat individual mounds with either more of the spinosad granules, the Medina Orange Oil/soap solution, Orange Guard, or very hot water.
Top Right: When ferocious fire ants invade your yard, skip the toxic insecticides and eliminate them with citrus oil and soap.
Bottom Left: This fire ant mound shows the intricate system of galleries within the nest. If your fire ant problem is more extensive than a fire ant mound or two, the “Texas Two-Step” method will help you get rid of fire ant activity on your property.
Photo By Alex Wild/Visuals Unlimited, Inc
Vicki Mattern is a contributing editor for MOTHER EARTH NEWS magazine, book editor and freelance magazine writer. She has edited or co-authored seven books on gardening, and lives and works from her home in northwestern Montana. You can find Vicki on Google+.