How To Kill Bugs In Your Soil: 5 Tips For Organic Pest Control

pest control for the soil

We hear so much about pesticides for plants, but often we omit the most critical part. The soil needs to be treated as well, and this part is equally important in the prevention of pest infestations.
If you have recently had close encounters with cutworms, grubs, and strawberry root weevils, you possibly need to treat your soil against pests.

How can you naturally get rid of the bugs in your soil?

There are mainly five methods to treat the soil using natural and non-toxic products, and they are the following:

  1. Diatomaceous Earth (D.E.)
  2. Wood Ash
  3. Hydrogen Peroxide
  4. Keep your soil healthy and clean
  5. Beneficial Nematodes

The ones I have listed are simple and relatively inexpensive organic pesticides for soil. Let’s try to delve a little into these topics:


Diatomaceous Earth is probably one of the most popular soil conditioners and organic pesticides for the garden. It is also known as D.E., the fossilized remains of diatoms, a type of hard-shelled protists. It comes in a crumbled white powder. It is mainly considered harmless to people and pets, and a safe alternative to pesticides. The tiny particles of D.E. stick to the insects dehydrating and killing them within 48 hours.

Diatomaceous earth powder is blended into potting mixes or applied directly on the ground. Besides, it adds porosity to the soil. It can retain fertilizers and release them gradually to the roots. The silica content of diatomaceous earth is absorbed into plant tissue and helps improve plant structure and resistance to pests and disease. Diatomaceous earth can help you to get rid of numerous insects, such as:

  • Ants
  • Cutworms
  • Gnats
  • Grubs
  • Blackflies
  • Whiteflies
  • Tick
  • Aphids

Just sprinkle on your plants some D.E. It will keep the topsoil dry and will desiccate gnats or larvae that land on the plant.

… And last, but not least:

  • Slugs. DE is made of microscopic sharp and ultra-fine silica particles that penetrate and inflict lethal cuts on the soft, tender bodies of these pests.

Wood ashes have a long tradition of use in the garden as organic pest control and fertilizer. Wood ash is alkaline and, therefore, useful as a fungicide and a pesticide. If sprinkled on the base of individual plants, it creates a hostile environment for foliage feeders like cutworms, caterpillars, and grasshoppers. Wood ash will irritate slugs and repel them. Be aware that ashes dissolve and disappear after rain or during irrigation. Remember that wood ash is alkaline and will affect the soil PH. Therefore, it is advisable not to use it in the proximity of acid-loving plants.


Hydrogen peroxide is considered safe in organic gardens because it quickly breaks down into oxygen and water molecules. This solution is generally diluted. The solution commercially available for gardening is usually the 3% one. Although it is usually used to prevent root fungus, Hydrogen Peroxide works very well as organic pest control for your soil. Hydrogen Peroxide helps to aerate the soil and avoid root rot. Root rot happens when the soil is too compact, and the roots suffer because they don’t get enough oxygen and nutrients. When absorbed into the soil, hydrogen peroxide breaks down and releases oxygen. Hydrogen Peroxide works great as soil pest control. It is effective against fungal diseases such as powdery mildew and works best against spider mites and fungal gnats. You can prepare your homemade spray by diluting the solution and combining it with an equal amount of water. Spray directly on the soil when digging planting holes. You can also spray it on the surrounding soil. By doing this, you will reduce the presence of pests such as spider mites, gnats, aphids, and other small critters. Be aware that spraying Hydrogen Peroxide will not kill eggs. Always wear gloves when handling this solution, as it could irritate the skin.

What does it mean to keep the soil clean? Don’t worry! I’m not asking you to start digging in the whole garden and clean it of stones and debris. Here is what you need to do to have clean and nourished soil:

  • Avoid tilling the soil: Farmers used to think that this process was necessary to incorporate air into the ground; however, now they argue if this has any benefits at all. When tilling the soil, we uproot everything, and this process ruins the best part of the earth, which is buried deep down, exposing it to the sun, air, and wind. By doing so, the best organic matter is dispersed or washed away by the rains. When we till with machines, we kill all sorts of beneficial insects, worms, and microorganisms that work on behalf of gardeners.
  • Feed your soil with compost: every spring, feed your soil with organic compost. This will help the soil restructure, and will strengthen it.
  • Mulch the soil: organic mulches such as grass, straw, coffee grounds, corn cobs, and manure retain moisture in the earth, avoiding erosion. Mulch decomposes into humus, improving the soil’s fertility, consistency, and structure.
  • Rotate Crops: this practice implies a scheme of rotation cultivation of different products on the same ground in different years or seasons. This technique reduces certain specific pests in the soil. Besides, it helps in reducing soil erosion and increases its fertility.

5. Beneficial Nematodes
Beneficial nematodes are becoming more and more popular for soil pest control. Beneficial nematodes are safe for humans and pets since they are entirely organic. They are safe to use in the soil and won’t harm other beneficial bugs such as bees or pollinators.
Beneficial Nematodes are tiny microscopic roundworms that mostly live in the soil. They work best against cutworms and grubs (more on this topic in this article). Their way of killing insects is quite creepy. They enter the larvae’s body through the mouth, anus, and respiratory openings. Then, they release their deadly bacteria into the host body, killing it within 48 hours. Once the host is dead, they transform its body into nutrients upon which they feed. They are easy to apply and cost-effective, however, the right timing and conditions are needed for them to be effective. The best time to release them is in late summer and early fall. This period coincides with the egg-hatching of specific pests, such as cutworms and grubs.

How to get rid of tiny silver bugs in your potting soil

The potting soil in our home pots is not immune to parasite contamination. Sometimes you may spot tiny silver bugs emerging from the soil when repotting or digging around your plants. They are most likely springtails or isopods, creatures attracted to wet, organic soil. Reducing your watering may do the trick and be enough to create a hostile environment for these pests. Or perhaps your plant is infested with fungus gnats? These are minuscule black flies that live on your plant, and when disturbed, a cloud of tiny flies lifts off the soil. They don’t damage the plants, neither do the larvae, but are unwelcome house guests nevertheless. A simple reduction in watering is often all you need to control this common houseplant pest.

In conclusion, it is possible to reduce bug populations in your soil without using harsh chemicals. The five steps discussed in this article can help you create a plan to get rid of bugs while protecting the health of your garden. Good gardening practices, such as improving the soil, removing debris, and keeping your garden healthy, can help prevent future infestations. With a bit of planning and effort, you can successfully kill bugs in your soil and ensure a healthy garden environment.

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Anat Goldberg

Hi! My name is Anat and I have lived all my life in the countryside. I grew on a farm in Northern Italy and from an early age, I took care of the animals on the farm and the family garden. Over the years I have developed a growing passion for organic cultivation and pest control.

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