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Are Ants in Raised Garden Beds a Bad Thing? 

Are Ants in Raised Garden Beds a Bad Thing? 

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Willie Moore
Latest posts by Willie Moore (see all)

If you have noticed ants on your raised garden beds, you may be wondering if they are harmful or not. While some gardeners fear that ants will damage their plants, others consider them helpful. So, are ants in raised garden beds a bad thing?

Ants in raised garden beds aren’t always a bad thing. They help decompose organic matter and aerate the soil, which improves drainage and soil fertility. Ants also prey on harmful insects, such as caterpillars which can destroy your plants. However, ants increase aphid populations, and invasive species can damage plants.

The rest of this comprehensive guide will explore a few topics related to ants in raised garden beds, including their benefits in a raised garden bed, potential problems, and how to get rid of them if you decide you don’t want them around.

Benefits of Ants in Raised Garden Beds

While ants can be a nuisance, they offer several benefits to your raised garden bed. Some of the benefits of ants in raised garden beds include:

Soil Aeration

As ants tunnel through the soil, they form channels that improve air circulation and drainage. These channels are especially beneficial in heavy clay soils, which can become waterlogged and compacted easily. Improved soil aeration helps roots grow deeper, leading to healthier plants and higher yields.

Organic Matter Breakdown

Ants accelerate the decomposition of organic matter, such as dead leaves and twigs. By breaking down matter into smaller particles the ants make the nutrients more readily available in your soil. This process helps to improve soil fertility as it releases these nutrients that plants can use for growth.

Predation of Harmful Pests

Garden pests such as caterpillars can wreak havoc on your plants when left unchecked. Ants prey on these pests, helping to keep their populations under control. This predation results in healthier plants, higher yields, and a reduced need for chemical pesticides, which can harm the environment (source).

Pollination and Seed Dispersal

While most ants don’t actively pollinate flowers, they can help disperse pollen and seeds. Ants collect honeydew, the sweet liquid aphids produce, which attracts the ants to your flowers. As they feed on the honeydew, pollen sticks to their bodies and is transferred to other flowers, aiding in pollination. 

Additionally, ants will often collect and store seeds in their nests. As they move, these seeds are scattered and can take root in new areas, helping disperse them.

Potential Problems Ants Can Cause in Raised Garden Beds

Unfortunately, ants can also cause some problems in raised garden beds. Some of the potential issues ants can cause include:

Increased Aphid Populations

While ants don’t eat plants, they protect and tend to aphids. These are small, sap-sucking insects that can damage plants. Aphids produce honeydew, a sweet liquid that ants love (source). 

In exchange for this food source, ants will protect aphids from predators and even help them spread to new areas. 

This symbiotic relationship between aphids and ants results in increased aphid populations, damaging your plants. Additionally, the honeydew produced by aphids can encourage the growth of sooty mold, a black fungus that can block sunlight from reaching your plants.

Weakened Plant Roots

While tunneling ants can improve soil drainage and aeration, they can also damage plant roots. This action is especially problematic for young plants with shallow root systems. 

The roots can become entangled in the tunnels, causing them to break or pull from the ground. This damage makes bent, stooping, or wobbly plants susceptible to disease and pests.

How To Control Ants in Raised Garden Beds

Despite their slew of benefits, ants can also be a nuisance. If you find that ants are becoming a problem in your raised garden bed, you can take a few steps to get rid of them.

Spread a Layer of Diatomaceous Earth

Diatomaceous earth (DE) is a substance made from the fossilized remains of diatoms. It’s naturally safe to use around plants and animals but deadly to ants. DE kills ants by puncturing their exoskeletons, causing them to dehydrate and die (source).

To use DE:

  1. Spread a thin layer of DE around the perimeter of your raised garden bed. You can also sprinkle it around plants that ants are targeting.
  2. Reapply after heavy rains or when you see the ant population starting to rebound.
  3. Wear a dust mask when applying diatomaceous earth to avoid breathing it in.

A Warning About Fire Ants In Raised Gardens

While some ant populations can be beneficial to raised gardens, fire ants are especially concerning and should be controlled. As an invasive species, they can cause significant damage to the health of garden plants.

How To Control Ant-Related Aphids 

Ants have a symbiotic relationship with aphids, protecting them in exchange for honeydew. If you can control the aphid population in your garden, you’ll also be able to get rid of the ants.

There are a few different ways to control aphids, including:

Hosing Them Off With Water

High-pressure streams of water can dislodge aphids from plants. Keep in mind that while this will remove the aphids from your plants, it won’t kill them.

It’s a short-term solution to your aphid problem. It’s best to do this early in the morning, so the plants have time to dry off before nightfall.

Introducing Ant Predators

Ladybugs, lacewings, and syrphid flies all eat aphids. You can attract them to your raised garden by planting specific flowers, such as dandelions, fennel, and cilantro. Alternatively, you can purchase them online or at your local garden center.

First, test it out on a small section of your garden to avoid plant damage (source).

Applying Insecticidal Soap

Insecticidal soap is a safe and effective way to kill aphids. This is a simple process that you can do at home by following these steps:

  1. Mix 1 teaspoon of dish soap and 1 tablespoon of vegetable oil with 1 quart (946 ml) of water
  2. Spray the solution on aphids and their eggs, covering the undersides of leaves where they like to hide.
  3. Repeat every few days until the aphid population is under control.

Pour Boiling Water on Ant Hills

If you see ants in your garden bed, it’s usually a sign there’s an ant hill nearby. These are small mounds of dirt that ants build to house their colonies. To get rid of these pesky critters, pour boiling water over the ant hills. This action will kill the ants and any eggs that are present. Do this early in the morning when the ants are inactive.

Final Thoughts

Ants can be valuable or devastating to your garden. They help aerate and improve soil drainage, accelerate organic matter breakdown, and control harmful pests. However, they can also damage plant roots and encourage the growth of aphids and sooty mold.

If ants are becoming a problem in your garden, spread a thin layer of diatomaceous earth around the perimeter. You may also control aphids by hosing them off with water, introducing predators, or applying insecticidal soap. Finally, pour boiling water over ant hills to kill the ants and their eggs.

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