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ask-ruth-pictureDear Ruth,

From Linda in Zirconia: Our small acreage (just under 4 acres) seems infested with all sizes and colors of ants. Since 2004, when we purchased theproperty, we have tried not to use chemicals on our lawn, forest or vegetables, but now the ants are about to overrun us! The little, common “sugar ants” get in the house, but we have smaller ants and the larger black and red ants outside as well.

We have tried lemons, cornstarch, and cucumber peels inside, as well as just plain keeping surfaces clean. We have recently put some Eco-granules outside in the ant trails and around the house, but as yet have noticed no significant decrease in population. If you happen not to be looking and step near the bed, your feet are immediately covered with stinging ants. What can we do safely, organically, and sustainably to control these critters?

From Kelly: We have a 30-acre mostly organic farm with horses and gardens. We like to stay away from using any poisons, pesticides, or herbicides. Do you know a safe way we can get rid of fire ants? We’ve tried boiling water on the anthills near the house, but it’s not feasible to carry boiling water all over our property. I’ve researched some available treatments, but none of them are completely nontoxic. Thank you!

Dear Linda and Kelly,

First, I have to tell you that fire ants and regular ants fall in two distinctly different categories. Please note that ants are industrious creatures who aerate the soil, help recycle dead bugs and animals, are themselves food for other creatures, and are part of the incredible web of life. That being said, I doubt I will ever find a soft spot in my heart for fire ants.

We’ll talk about regular ants first. Ants are seeking food and water. In the house, you want to keep all surfaces clean of food particles, and fix any water leaks. Once ants find a supply of food or water, they leave a scent trail for their nest-mates to follow straight back to the mother-lode…your kitchen counter, under your sink, or the cookie crumbs in your child’s bedroom. Follow the trail of ants to find out where they are coming in, remembering to check around water pipes. Some sites recommended detering the ants by spraying a natural citrus cleaner or Dr. Bonners Peppermint Soap to mask their trail (spray the cleanser/soap on the trail and don’t wipe off). Seal their entry points with caulk or expandable aerosol insulating foam. Alternatively sprinkle the entry site, especially vertical surfaces, generously with talcum powder. Cut any plant material away from your home, so that ants cannot use it as a bridge to enter your home. Pull mulch back from the house so it is not providing a hospitable habitat for ants.

Even though bait takes longer to work than products that kill ants immediately, bait is the most effective tool to use in eliminating ants. Ants will carry the bait back to the nest and feed it to other ants and the queen. If you just get rid of the ants that are parading across your wall (they usually show up just before company arrives), there are hundreds of thousands more in the nest ready to march in right behind them. According to Orkin, “worker ants may live as long as seven years and the queen may live as long as 15 years.” You want slow-acting bait so the ants will remain alive to carry the bait back to the nest and successfully contaminate quantities of ants. Studies show that Boric Acid formulas achieved 95 to 100% control (including fire ants) within 8 weeks, and possibly in 3-4 weeks. See Tips For Effective Ant Baiting.

Bait recipes: Keep all baits/poisons away from food, drinks, pets, children, and wildlife. All baits must be kept fresh and moist. It is recommended that you change the recipe/product occasionally (from honey to molasses in homemade formulas, for instance) so the ants continue to visit your bait trap with enthusiasm. To determine whether the ants are sugar ants or meat ants, set out separate blobs of peanut butter and jelly and see which food the ants prefer. Direct exposure of boric acid bait material to garden soil may cause an excess of boron in the soil.

Recipe: Mix 1/8 teaspoon boric acid (available at drug stores) or 20 Mule Team Borax (grocery stores) with 7 teaspoons of bait material. For sugar ants, use something sweet (honey, jelly, molasses, syrup, sugar) for the bait material. For meat ants, use fish oil and grease for the bait material. Mix boric acid with bait material, put in a jar lid or bottle cap, and place along an ant trail. The larger scale recipe is 1 tsp. Boric Acid to 1 cup (up to 2 cups) bait material.

OR…Mix 1/3 cup Molasses, 6 Tablespoons Sugar, and 6 Tablespoons Active Dry Yeast. Spread on a plastic lid near on outdoor ant bed, or on a cardboard strip along an indoor ant trail.

Commercial products like Terro® (in grocery stores) or Drax® are also effective boric acid baits. I have used Terro® for years.

Repellants won’t get rid of ants, but they will drive them off. Herbs that repel ants include mints, tansy, rosemary, and pennyroyal. Mint is often found planted near doorways of old houses because of its reputation for repelling ants. After ants colonized my new mailbox, I kept sweeping the ants/ant eggs out of the mailbox so the mailman wouldn’t balk at delivering my mail. On a whim I put a bunch of fresh rosemary clippings in the back of my mailbox. The ants disappeared overnight, and did not return until months later when the rosemary got too old.

Ants also feed on the sugary material secreted by aphids and other insects called honeydew. Barriers to discourage or prevent their movement include a band of sticky material (such as petroleum jelly, tape, or Tanglefoot®) or talcum powder and can be applied to the base of plants, trees and at other points of entry. Once the sticky material is dust covered, it must be replaced to be effective.

Instant grits, cucumber or orange peels, boiling water…there are lots of home remedies for ant problems. You have already tried a few of them. Here is an updated link to experiments about various remedies and their effectiveness

Kelly, I doubt there is a “completely non-toxic” solution other than water, but gently pouring three gallons of boiling water on ant beds did result in a 60% population reduction (use extreme caution with hot liquids and angry fire ants).

Although fire ants have been spotted in the two most western counties of Western North Carolina, most of the mountain counties are free of fire ants. Encountering fire ants will provide you with an unforgettable experience, and some people are highly allergic to their bites. I grew up around fire ants and consider approaching a fire ant bed only with extreme caution. When weeding garden beds, you have less than half a chance to pull that weed, before fire ants are rushing up your arms – at the speed of light – biting fiercely as they go…and you cannot weed that spot again for hours (maybe days). Yes, the bites feel like fire and fire ants are beyond aggressive! Fire ant bites look like a pimple with a whitish head on it by the next day. An Extension agent I know in New Orleans says…the only time he ever took his pants off in public involved fire ants.

The red imported fire ant came to the USA in boat cargo from Brazil around 70 years ago. It out-competed the imported black fire ant, and the native Texas red fire ant (not considered a pest). The Brazilian fire ant is not considered a pest in Brazil because they are kept in check by natural predators. No natural predators exist in the USA, but work is in progress using a fly that decapitates fireants, and other biological controls ~ including Fire ant disease (Thelohania solenopsae) and different nematodes. On the up side, fire ants are actually considered a beneficial predator in some crops, such as sugar cane and cotton, and they will help reduce tick populations. That is little consolation to landowners infested with fire ants. These aggressive ants have become such a scourge in most of the southeastern USA, and parts of the southwest, that many eradication methods take on a tone of frenzied desperation.

Individual bed treatments are preferred over broadcast treatments for fire ant control, because native ant populations are less compromised in the process. Target the mound and an area 1-3 ft around the mound. Fire ants are best treated on cooler, sunny days and treatment is least effective during the hottest part of the summer. Ants will often desert the treated mound and just build another mound nearby; so long term effectiveness is an issue.

Because allowable substance rules frequently change, Organic Growers School cannot vouch for any recommendations as certifiable. Please note that Certified Organic growers should always check with their certifier before applying any product. As I understand it, fenoxycarb products, such as Award Fire Ant Bait, are no longer allowable for organic growers. Spinosad products have shown some success against fire ants.

Mound Drenches for Fire Ants: Entrust® (spinosad), Monterey Garden Insect Spray (spinosad & OMRI), Greenlight Fire Ant Control with Conserve® (spinosad), Safer Brand Fire Ant Killer (citrus-peel based), and Citrex ® Fire Ant Killer name a few products. Some are approved for home use only. Clove oil, thyme oil, and citus-peel concoctions were all mentioned as possible mound drenches.

Baits for Fire Ants: Ferti-lome Come and Get It (OMRI), Ortho EcoSense Brand Fire Ant Bait Granules, and Safer Fire Ant Control Kit are baits mentioned as organic alternatives, possibly certifiable. Boric acid baits, as discussed above, are also recommended for fire ant control. I didn’t see any mention that boric acid baits are OMRI approved, but they are relatively effective and safe when used properly.

Other Options: Insecticides such as rotenone, pyrethrins, and pesticide-grade/food-grade (not swimming pool grade) diatomaceous earth, can act as mound treatments, but the product must come in contact with and kill the queen(s) to control ant colonies. Many of the tests I reviewed did not give high marks to diatomaceous earth, and it should be applied only during periods of dry weather to be effective.

Some of the mentioned products are available locally at area garden centers, like Reems Creek Nursery or Fifth Season. Some are available through Johnny’s Selected Seeds, Peaceful Valley Farm Supply, or other on-line sources.

Organic Growers School Disclaimer: Rules and regulations are always in a state of flux. Organic Growers School makes no claims about any product ~ as to it’s effectiveness or that it is certified for organic production, and assumes no responsibility for dangers involved in handling pesticides or ants. Read and follow all safety and labeling recommendations for any product you use, and always exercise caution in proximity to ants.

Best of luck with the ants,

Ask Ruth © 2013 Ruth Gonzalez & Organic Growers School

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Ruth Gonzalez

Author: Ruth Gonzalez

Ruth Gonzalez is a former market farmer, gardener, and local food advocate who wants to see organic farms proliferate and organic gardens in every yard. She serves on the Organic Growers School Board of Directors, and in her job at Reems Creek Nursery, Ruth offers advice on all sorts of gardening questions, and benefits daily from the wisdom of local gardeners.

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