Ants in your garden can feel threatening. After all, they are insects and usually don't travel alone. When you see lines of ants heading up the sides of container plants or streaming into a garden bed, it can feel like an invasion. But stop and take a deep breath. The fact is, ants in house plants are often are beneficial insects. They don't hurt your plants and can actually aid them. But if you want to reduce their numbers or nudge them into moving on, you have more than one option.
Ants in Plants
Ants and plants seem to go together. If you have any sort of a garden at all, you'll probably see ants from time to time. This can include ants in potted plants, ants in flower pots and ants in house plants. So what's a gardener to do?
The first thing to do is reflect on the role ants play in a garden. Tunneling ants are little rototillers, aerating the soil like earthworms do and redistributing nutrients. They also help recycle by collecting dead insects and transforming then into soil fertilizer. Ants also help disperse seeds, especially with flowering plants.
Ants aren't interested in munching your plants as some bugs do. Instead, they are looking for stem nectar. They will get rid of plant-eating bugs that can harm your plants in order to dislodge them from sticky stems and leaves. And in that role, they also protect some insects, such as the caterpillars of some butterfly groups that produce a sweet substance known as honeydew. The ants love honeydew and look after the caterpillars until they become butterflies. In turn, ants serve as food for other beneficial insects, frogs, toads, birds and even some mammals.
Aphids Attract Ants
If your ants happen to be one of the few types that are bad for your garden, such as carpenter ants or stinging fire ants, you'll want to get rid of them. You may also want to reduce the population of regular ants in potted plants or house plants. One way to do this is to take out the aphids.
Although some caterpillars produce the honeydew ants love, much more is produced by aphids, a true type of nuisance bug in the garden. Just like ants herd and protect caterpillars that produce honeydew, they do the same with aphids. You want to get rid of aphids anyway because they suck out plant juices and damage plants. Just blast them off the plants with a hose or use a spray bottle with a mix of water and dish soap. Once the aphids are gone, the ant population will decrease significantly.
Pesticide for Ants in Plants
Perhaps the easiest method of getting rid of ants is to use ant bait stations. You buy them commercially and set them in the house or outside where ants are a problem. Yes, these are pesticides. Ants die when they collect the bait from the station and take it back to the colony.
Getting Rid of Ants
If you don't want to turn to pesticides for ants in plants, there are various ways you can kill ants without chemicals. One natural ant killer for the garden is a substance called diatomaceous earth. This natural substance, available in hardware stores, kills ants without hurting plants. But you'll need to wash it off any harvest after treatment. And, like other ways of killing ants, it is likely to kill other beneficial insects as well.
Some people swear that a mix of red paper flakes and chili pepper, crushed and spread around your plants, keeps ants away. Others use a spray of hot sauce and water. Some experts recommend a spray made from equal parts of vinegar and water. If you find a nest in the soil, flooding it with water from the hose should reduce the population.
From Alaska to California, from France's Basque Country to Mexico's Pacific Coast, Teo Spengler has dug the soil, planted seeds and helped trees, flowers and veggies thrive. A professional writer and consummate gardener, Spengler has written about home and garden for Gardening Know How, San Francisco Chronicle, Gardening Guide and Go Banking Rates. She earned a BA from U.C. Santa Cruz, a law degree from U.C. Berkeley's Boalt Hall, and an MA and MFA from San Francisco State. She currently divides her life between San Francisco and southwestern France.