Organic Ant Control

Posted by Katie Elzer-Peters
August 19th, 2008
Filed in Garden Pests and Diseases
Tags: ants, bugs, pesticides, pests, poisonous, repellents

Photo by Il conte di Luna

Ants are part of the garden. They help decompose organic material. They can also bite, sting and devour a wood frame house. If you have a couple ant colonies and they are doing no harm, leave them be. Think of them as nature’s cleaning maids. However, if ants take control of the garden and raid your kitchen, or fire ants decide to take up residence, there are a few organic options for eradicating them.

Boric Acid

Boric acid is a relatively safe, naturally occurring compound that can be used for insect repellent. It is poisonous if ingested in large quantities. The median lethal dose is between 5-20 grams/kilogram, putting it just a bit higher than table salt. Unless someone eats borax out of the box with a spoon, it is unlikely they will be poisoned. That said, it is always a good idea to keep any chemicals—natural or synthetic—locked away from the reach of children.

Boric acid can be spread as a bait for ants. Thoroughly mix a 1:5 ratio of boric acid and sugar into water, and soak a piece of cotton to absorb the mixture. Place the cotton near the ant colony, and the boric acid will be taken back to the colony and eradicate it. The boric acid acts as a stomach poison. If you find dead ants near the bait, dilute with more sugar. The ants are poisoned before taking the bait back to their nest, rendering it ineffective.

This may take a few weeks, and the queen must be destroyed before the colony is gone.

Mint

Peppermint is a common ingredient of natural insect repellent sprays for the house. You can make peppermint extracts or purchase them at the hardware store. The ants do not like the smell of mint. It is important to NOT add sugar to the mint, as the sugar will counter the effects of the mint spray.

Diatomaceous Earth

Despite its alien-sounding name, Diatomaceous Earth is actually fossilized remains of diatoms—tiny sea creatures—that are ground up into a powder. The particles have sharp edges that cut up the bodies of the ants. Diatomaceous Earth is not toxic, but because of the sharp edges, it can cause harm if inhaled.

Place in the ant’s path to disrupt them, and in and around your garden and flowerbeds where problem areas occur to tell ants that this is a dangerous place to be. Diatomaceous Earth cuts into the shell of any soft-bellied insect, such as ants, slugs, and cockroaches, dehydrating and killing them. However, it will also affect beneficial insects, so don’t use it everywhere.

Boiling Water

A cruel but effective method, slowly pour about three gallons of boiling water directly on the colony. Do this in mid-morning when the ants are active, and repeat every day. You are not drowning them (as ants can survive in water), but literally burning them. The key is to scald and kill the queen. Warning, this will also kill or damage any vegetation directly affected.