Diatomaceous earth (DE) has gained popularity as a natural and effective solution for pest control in gardens and homes. DE is derived from the fossilised remains of diatoms, microscopic aquatic organisms. It’s a chalk-like powder that can deter and eliminate a wide range of pests without the use of harmful chemicals. Below, we’ll discuss the intricacies of diatomaceous earth, explore its applications, discuss its effectiveness against different pests, address safety concerns, and provide tips on how to use it for optimal results.
What is Diatomaceous Earth?
Diatomaceous earth is a sedimentary rock that is composed of the fossilised remains of diatoms, which are ancient, single-celled algae. These diatoms have hard, silica-based shells, making them ideal for creating a natural insecticide. DE comes in various grades, but for gardening and pest control purposes, it is best to use food-grade DE, which is safe for humans, pets, and the environment.
How Does Diatomaceous Earth Work as a Pest Control Agent?
The unique structure of DE makes it an effective pest control agent and when pests come into contact with DE, the microscopic, sharp edges of the silica particles penetrate their exoskeletons, causing dehydration and eventual death. The abrasive nature of DE also damages the respiratory systems of insects, further contributing to their demise. This mechanism of action makes diatomaceous earth an excellent solution for controlling pests with exoskeletons. Those are mainly ants, beetles, fleas, cockroaches, and bed bugs. However, it is also effective at stopping slugs in their path.
The Effectiveness of Diatomaceous Earth Against Different Pests
Diatomaceous earth is a versatile pest control solution that can effectively target a wide range of insects. Here’s a breakdown of its effectiveness against common pests:
Aphids and Caterpillars
While diatomaceous earth may not directly kill aphids and caterpillars, it can act as a deterrent due to its abrasive nature. By creating a barrier of DE around plants, you can discourage these pests from infesting your garden.

Slugs and Snails
Slugs and snails dislike crawling over diatomaceous earth due to its sharp particles. Sprinkling DE around vulnerable plants or creating a ring of DE can help protect your garden from these slimy pests.
Fleas and Bed Bugs
Diatomaceous earth is highly effective against fleas and bed bugs. Its abrasive properties penetrate their exoskeletons, leading to dehydration and death. Apply DE around pet bedding or infested areas to eliminate these pesky parasites.
Ants and Roaches
Ants and roaches are no match for diatomaceous earth. By creating a barrier of DE around entry points and infested areas, you can deter these insects and prevent them from reaching your home or garden.
Other Insects
DE can also target mites, millipedes, earwigs, silverfish, crickets, and other insects with exoskeletons. Its ability to dehydrate and damage their protective layers makes it an effective natural pesticide.

It is important to note that it is not effective against all pests. For instance, it may not be as effective against caterpillars with thick mucus layers or earthworms, which have adaptations that protect them from its abrasive effects.
Using Diatomaceous Earth Safely and Effectively
While diatomaceous earth is generally safe, it is crucial to take precautions to ensure its proper and safe use. Here are some guidelines for using DE effectively and without causing harm:
Choosing the Right Type of Diatomaceous Earth
When purchasing diatomaceous earth, opt for food-grade DE, as it is the safest option for use in gardens, homes, and around pets. Avoid using DE intended for pool filtration, as it may contain higher concentrations of silica and other impurities that can be harmful to humans and animals.
Applying Diatomaceous Earth
To use DE as a part of your pest control arsenal, follow these steps:
- Identify any Problem Areas: Find out where the insects are likely to infest or present themselves. Look for signs around entry points, crevices, or areas around plants.
- Create a Barrier: Sprinkle a thin, even layer of diatomaceous earth around the affected areas. Ensure that there are no gaps in the barrier that pests can easily pass through.
- Dusting Leaves (Optional): If pests are damaging the leaves of your plants, you can lightly dust them with diatomaceous earth. However, avoid applying DE directly to flowers to protect pollinators. Use an applicator for more accuracy and to keep your other tools free from the substance.
- Reapplication: Diatomaceous earth loses its effectiveness when wet, so it is important to reapply after rainfall or heavy dew. Regular reapplication ensures continuous pest control.
Safety Precautions
While diatomaceous earth is generally safe, it is important to take precautions to avoid inhaling the fine particles. When applying DE, wear a dust mask and eye protection to prevent irritation. Avoid creating airborne clouds of DE and keep it away from high-traffic areas to minimize the risk of inhalation.
Diatomaceous Earth Products
Additional Uses and Benefits of Diatomaceous Earth
DE offers several additional benefits beyond pest control. Here are some ways you can make the most of this natural substance:
Soil Improvement
DE can improve soil structure and drainage. Its porous nature allows it to absorb excess moisture, reducing waterlogging and promoting healthy root growth. Incorporate DE into your garden soil by mixing it in the top few inches or adding it to your compost pile.
Silica Source for Plants
DE is a valuable source of silica, an essential nutrient for plants. Silica contributes to stronger cell walls, improved drought resistance, and increased overall plant health and through using diatomaceous earth in your garden, your plants are going to benefit from the extra source of this mineral.
Livestock and Poultry Health
Diatomaceous earth is commonly added to livestock feed as a natural dewormer. It can help control internal parasites in animals, promoting their overall health and well-being. Additionally, DE can be used in poultry environments to combat mites and lice.
Environmentally Friendly
It is a natural pest control and it poses minimal risk to the local environment. It doesn’t cause harm to the soil, nor to any local water sources, birds, or other wildlife, and when used responsibly, DE can be a sustainable and eco-friendly pest control solution. One of the only drawbacks is that it is not as targeted as some biological pest controls.
Conclusion
Diatomaceous earth is a versatile and effective natural pest control solution. Derived from fossilised diatoms, it works by dehydrating and damaging the exoskeletons of insects, leading to their demise. DE can target a wide range of pests, but it is important to use it selectively and with caution to avoid harming beneficial insects and pollinators. By following proper application techniques and safety precautions, you can harness the power of diatomaceous earth to protect your garden and home from unwanted pests while promoting a safe and environmentally friendly environment.