Why Are Ants in Your Garden? They Live There

It turns out your garden is pretty much the perfect environment for many types of ants. Most species love to build underground or aboveground nests, and loose, turned soil allows them to quickly tunnel and build to their hearts’ content.

Of course, that doesn’t take into account that you might prefer your garden paths clear of the mounds they build. It also leaves you dealing with stinging bites if your new tenants are fire ants or another biting species. Even though ants may be natural, they’re not always wanted, and some can even be harmful to the plants you’re growing.

But don’t panic at the first sign of ants. Some types are helpful, removing debris and attacking pests while staying out of your way. The key is identifying the type of ants in your garden before taking action.

This will help you decide if you can live with your six-legged companions or need to remove them with one of the many natural ways to kill ants in garden spaces.

Identifying Common Garden Ants

Color alone isn’t enough to identify ants down to a level where you can predict if they’re trouble. You’ll need to estimate their size and check out their preferred nest or mound to get a good idea of what you’re dealing with.

Yellow Ants Are Mellow

Small yellow to tan ants that smell like citronella when crushed are known as citronella ants. They can swarm an area and cause a nuisance, but they will eventually retreat back underground and leave your plants alone. These ants need moisture and like to build their nests under intact wood, slabs of stone or concrete, or other materials that trap moisture.

They indicate the presence of aphids on the roots or stems of plants, which they farm for sweet honeydew. Treating your plants and garden soil with an aphid treatment will usually drive these ants away without any further treatment targeting them.

Field Ants Farm for Food

Field ants, larger black ants with rounded abdomens, also tend to farm aphids and exhibit similar issues. They can form large, round, relatively low mounds that might disrupt your garden beds or trip you when placed in paths. These ants also tend to carry seeds away that you have planted, and may ruin outdoor equipment such as sprinklers.

They’re easily removed if necessary, and, as with citronella ants, tend to leave when aphid infestations are removed.

Pavement Ants Play Nice

Small reddish brown ants forming large nests that you disturb when working in the garden are often pavement ants, especially if they’re nesting in plain dirt and not rotten wood. They’re not as red as fire ants, but still may mildly bite you. Pavement ants tend to burrow underground and stay under materials like concrete slabs, pavement, and wood.

However, they sometimes make a small donut-shaped mound with a large center. Unless they’re a nuisance or in the way, they’re not likely to cause any real problems and can clean up garden debris while encouraging pollination.

They’re one of the easier ants to leave in place, as long as they’re not excavating holes in your path that could twist an ankle.

Wood Burrowing Ants Create Big Nests

If you’re finding ants in mulch or rotting wood you’ve added to the garden for organic material, you likely have either acrobat or carpenter ants. Acrobat ants are small, under 1/8th of an inch, while carpenter ants are noticeably larger. Both can be red or black.

They’re not really problems for the garden itself since they consume many types of pests. However, you don’t want them to spread into your home. If you’ve noticed these ants around your garden or perimeter, make sure no leaks or moisture issues exist in the lower parts of your home.

These ants won’t move into dry wood, so unless you have a hidden rot problem, you should be able to co-exist with them.

Fire Ants Pose a Serious Hazard

The ants you should take the most seriously when planning removal are those small red creatures known as fire ants. A few species go by this common name, but all of them are invasive, build large nests that can damage plants and destabilize the soil, and create a painful sting when biting.

The bites can even threaten the health of a pet, child, or you in severe situations. They produce large mounds of loose soil with no visible entry or exit points, and they swarm when disturbed. Take care to treat the mounds without jostling them too much, since you run the risk of being bitten.

Fire ants are not found in all 50 states yet, but they’re spreading and reaching new areas each year. ^[1] Ant Pests. Geographic Distribution of Fire Ants. Not all red ants are fire ants, so if you’re not sure what you’re dealing with, check in with a local pest control company or extension office to find out if these species are known in your area.

When Ants Attack: How They Can Cause Problems in the Garden

Ants aren’t always problems in the garden, but they can lead to a few issues that might interrupt your enjoyment of the space.

Biting

Only fire ant bites will cause any lasting irritation for most people, but it’s never fun to feel a pinch when digging in the soil or pruning your plants.

Eating Stems and Roots

Although they’re rarely found in North America, some ants can eat the stems and roots of garden plants.

Encouraging Pests

Ants that farm aphids for their sticky honeydew can accidentally encourage these pests in your garden rather than eliminating them. Learning how to stop ants from farming aphids can save sickly plants.

Making Holes

Underground ant nests often collapse when you’re walking or pushing a wheelbarrow over them. This could lead to a trip hazard or drainage issues.

Filling Equipment With Dirt

Some ants, including fire ants and big-headed ants, pack dirt into equipment such as sprinklers, irrigation tubing, and garden bed edging to create nests. This could lead to parched plants and a need for new equipment.

Of course, ants aren’t all bad. If you can co-exist with them, most species will provide benefits, including:

• Pest control, especially from hunting ants like carpenter ants
• Pollination to increase vegetable and fruit production
• Soil loosening effects that prevent compaction and increase water and oxygen penetration in the root zone
• A healthy food web that’s less prone to sudden pest explosions.

Dealing with Problem Ants

From deterrents to more permanent methods of removal, you’ve got a range of options for dealing with ants in the garden.

Putting Down Bait

Bait is a slow but steady option for shrinking ant colonies until they collapse and disappear. While it can work well in a small garden, it tends to have a limited effect in larger spaces. To boost the effect of any ant baits you spread, treat your plants for aphids and other honeydew-producing pests at the same time. This robs the ants of a food source, encouraging them to take the bait.

Liquid baits also tend to work better since solid bait traps are often covered by soil when placed in an outdoor garden setting.

One eco-friendly ant control option you can DIY is this borax ant bait recipe. It's a simple way to kill ants without using chemicals because the borax breaks down into boron, a trace mineral that plants can use.

Mix together:

• 3 parts white granulated sugar (such as 3 tablespoons)
• 1 part granulated borax for laundry and garden (such as 1 tablespoon).

Place this homemade ant killer a few feet away from any nests or mounds you find. Bait placed directly on the mound is generally ignored.

Deterring and Repelling Ants

Controlling other pests, such as aphids, goes a long way in discouraging many types of garden ants. But if that’s not enough, you can try spraying ant repellents for garden use. Choose a product tested for plant safety.

Most products aren’t safe to use on vegetables or fruit you’re going to eat, but you can still carefully apply the sprays to the base of plants to keep ants away.

Start with the perimeter of the garden, then move down each row or path and try to surround each bed or plant with a ring of the spray or powder. Apply regularly to refresh the repellent effect.

Removing rotten wood and materials that trap moisture can also greatly discourage new nest-building activity from many species.

Permanent Methods for Killing Ant Colonies

Bait and repellents work slowly. For an immediate end to ants that are damaging your garden equipment or biting you and your pets, it’s time for a direct treatment of the nest. That means locating every ant mound, colony, or nest in your garden, which can be a challenging task since they tend to burrow underground.

Look for ants and try to follow them back to a colony or nest to locate where to apply treatments. Most ant colony treatment liquids are not safe for use around plants, so you may need to remove or relocate your favorite plants before applying the treatment.

Boiling water or undiluted horticultural vinegar are two DIY options that will cause relatively little damage to nearby plant roots. Granules or dusts containing permethrin or deltamethrin work well when applied to an opened nest, while liquid treatments with bifenthrin, cypermethrin, or a cyhalothrin compound will soak into the ground. ^[2] University of Minnesota Extension. Ants; 2024

Keep treating the nests until there are no more signs of infestation. Avoid pouring chemicals like kerosene or gasoline onto the mounds, and definitely don’t try to set these flammable substances on fire. It’s not necessary to go to such lengths to get rid of ants. ^[3] Ferguson College of Agriculture. Fire Ants - Quick Tips.

When Ants Won’t Go: Where to Turn For Help

If you are concerned that the ants are moving into your home or just can’t get them out of the garden, a pest control company can help. These experts can identify all of the ants in your garden, tailor the treatments to each nesting type, and make sure they don’t spread or return.

Don’t let insects in your garden bother you during your enjoyment of your flowers or vegetable plants. Take action at the first sign of ants with your chosen ant solution for the vegetable garden to limit their presence. Keep ants at a level where you can tolerate them without risking damage to your plants.