How To Get Rid Of Ants In Your Garden Beds (And Keep Them Away)

Ants are seldom included in the list of garden pests because some are beneficial because they snack on unwanted insects. However, every Southerner knows that aggressive fire ants are never welcome, and other species can also cause lots of problems. It’s important to learn about different types of ants before bringing out toxic chemicals, especially in edible gardens. Learn how to use natural and safe methods to keep ants out of your garden.

Understanding Ants in the Garden

Common Ant Species

There are more than 300 species of ants in the Southeast, including non-native invaders. The most prevalent species in the garden are:

• Black garden ants: Black garden ants tend to nest in grassy areas. They feed on pests such as cutworms and root-feeding white grubs. However, they do support sap feeders, such as aphids and scale insects, to collect their nutrient-rich waste liquid (honeydew). While their mounds can be unsightly in lawns, the ants do not sting.
• Little black Ants: These ants nest under rocks or loose tree bark and can often be found on plants collecting nectar or honeydew from aphids or scale insects. They also eat live and dead insects and spiders, and may pollinate plants as they forage for food among flowers.
• Fire ants: The red and black imported fire ants, introduced from Argentina or Brazil, have wreaked havoc in the South due to their aggressive stinging habits. These two species can mate with one another, producing a hybrid, which can produce viable offspring. The dome-shaped mounds usually appear in flat, sunny areas, reaching 1 ft high or higher, with 100,000 to 500,000 individual insects.
• Carpenter ants: Carpenter ants chew tunnels and chambers in structural timbers, wooden fences, trellises, and outdoor furniture. They do not use wood as a food source but remove it to make tunnels and galleries in which to raise their young. Most are large, black, and feed on live and dead insects and honeydew.

The Role of Ants

Having some types of ants in the garden can be beneficial because they move approximately the same amount of soil as earthworms, loosening and aerating the soil, which helps to increase water movement into the ground. They keep the ecosystem clean of insect carcasses and help break down plant and animal matter. Ants can carry seeds and help plants disperse into new areas.

Unfortunately, beyond the painful stings some can deliver, ants can also have detrimental effects on the garden. Some species protect or “farm” sap-sucking pests like aphids. The aphids feed on plant juices and excrete honeydew, a sugary substance that ants crave. In return, the ants defend the aphids from natural predators like ladybugs, allowing their numbers to surge out of control, leaving weak, disease-prone plants. If ant mounds overrun the garden, the underground activity can disrupt soil stability and lead to compromised root systems, especially for tender, new plants.

Natural Methods to Deter Ants

Disrupting Ant Trails

“The acetic acid in vinegar can temporarily disrupt ant trails by breaking down the pheromones they follow,” says Casey Bishop, President of Dr. Killigan’s Plant Powered Pest Control Products. “Spray it along their paths to confuse foragers and slow their progress. The scent fades quickly, so it needs frequent reapplication.” Using lemon juice or water infused with citrus peels can have the same effect. However, if there’s a strong enough food source, ants will usually find another route into the garden. Neither method will get rid of ants.

Natural Repellents

“Sprinkling cinnamon, cayenne pepper, and even coffee grounds can discourage ants by irritating their senses or disrupting scent trails—but their effectiveness really depends on the species and the environment,” says Bishop. “Essential oils, on the other hand, especially peppermint, citrus, or clove, are far more consistent when properly diluted and applied. They don’t just repel—they can also interfere with ants’ communication systems.” All natural disrupters and repellents require reapplication after rain or irrigation to remain effective.

Physical Barriers

“Diatomaceous earth works by physically damaging the ants’ exoskeletons, causing them to dehydrate and die,” explains Bishop. “When applied in a dry, thin layer along entry points or trails, it can offer multi-day protection.” He adds that using baby powder, talcum powder, or chalk as a barrier to keep out ants is largely anecdotal and unproven.

Eliminating Ant Colonies Naturally

There are plant and mineral-based commercial products that kill ants without the use of insecticides. Or, you can use these DIY methods that have proven effective.

• Borax Bait: Combine borax with sugar to attract and kill ants. Place the bait in a container that is not accessible to children or pets. The bait can cause gastrointestinal upset if consumed in large amounts.
• Boiling Water: Pouring 2 to 3 gallons of boiling water on a fire ant mound will kill the mound about 60% of the time. You’ll have more success if you pour in the water at night when most ants have returned to the nest. However, hot water will also kill any grass or surrounding vegetation that it touches.

Preventative Measures

The best way to control ants in the garden is to be observant and take preventative measures before ants become a problem. If you begin to see a large number of ants, check plants for aphids and other sap-sucking insects. You must treat the plant-damaging aphids first so the ants will then seek food elsewhere. Ants are also attracted to fallen fruits and vegetables, so remove overly ripe or accidentally dropped food.

Ants dislike chrysanthemums, mint varieties, tansy, and marigolds, so add them to your garden as deterrents. Since aphids avoid plants in the garlic and onion families and ants love aphids, add them to the garden, as well. And, if you’re willing to sacrifice one plant for another, use nasturtiums to lure ants away from other plants in your garden.

When to Seek Professional Help

“You don’t need to call in pest professionals every time you spot an ant mound, but there are moments when an ant problem crosses the line. If you’re dealing with invasive species like fire ants that pose a risk to pets, children, and yourself, it’s time to act,” says Bishop. However, it’s critical to know exactly what’s being used, especially in vegetable gardens or around edible plants. Consult with your local county extension service office and use a reliable, transparent company.