DIY Guides Diatomaceous Earth For Roaches: Does it Kill Them?

Diatomaceous Earth For Roaches: Does it Kill Them?

Thinking of using Diatomaceous Earth to treat roaches in your home? Not only is DE effective, but it’s also safe and often cheaper to use. Find out all you need to know before using DE in your home to prevent roaches in your home.

Cockroaches are annoying pests that often seem like they will never leave your home. Their excellent survival schools make a complicated problem for homeowners who want a pest-free environment. They also look just like several other bugs, making them hard to identify quickly unless you are familiar with them. They also smell, which can be a cause for concern to sensitive groups.

If you have a cockroach infestation on your hands, you want to find an effective solution as soon as possible. Roaches aren’t only gross insects, but they can damage your indoor plants and expose your family to diseases and allergens.

However, calling an exterminator can be expensive, and most of the readily available products at your local store are full of dangerous chemicals. However, many of the safer DIY treatments aren’t quite as useful – except for one.

Diatomaceous earth, or DE, is one of the most effective methods of safely treating a roach infestation.

What Is Diatomaceous Earth?

This powdery substance comes from the remains of diatoms or microscopic algae organisms. Their skeletons are rich in silica, which is left in riverbeds and soil when they die.

The silica then reacts with oxygen in the air to form silicon dioxide, which people have used to kill pests since 1960. Diatomaceous earth has since become a standard, natural pest control method, but you can also use it for other purposes.

Check everyday household products like toothpaste, paint, medicines, drinks, and water filters for diatomaceous earth. While this substance can be deadly to pests, there are various degrees of toxicity. The food-grade form is usually safe for human consumption.

Is it Effective For Roaches?

Diatomaceous earth powder
Diatomaceous Earth is a substance that can help control multiple types of pests.

Yes, Diatomaceous earth can be used as an effective treatment for roaches and is exceptionally potent. More and more people have realized the benefits of DE and opting to use the powder over more dangerous chemical options.

Not only does DE work against cockroaches, but it also helps remove fleas, bed bugs, and ticks. Diatomaceous earth can be used both as an insect treatment and a preventative measure to avoid future infestations. It’s one of many different approaches that homeowners seek when trying to self-treat insects in their home.

How Does It Work?

Diatoms have a beautiful, unique silica skeleton that resembles a glass shell. When they die, their bodies become fossilized in the soil. At a microscopic level, the silica remains abrasive and sharp.

When a cockroach comes in contact with DE, the powder works against the insect in two ways. First, the sharp particles break down the cockroach’s hard exoskeleton. Then, it sucks out the oils from the roach’s shell, which destroys their protective layer even more.

These two forms of attack essentially remove the cockroach’s ability to keep moisture in their bodies. Since they thrive in warm, moisture-filled areas, their own bodies’ dryness will quickly kill them.

In simpler terms, DE dehydrates the roaches, and they eventually die.

How Long Does It Take to Work?

Once the roach actually comes in contact with the diatomaceous earth, the effects are relatively quick. It won’t be as instantaneous as a chemical bomb or powerful insecticides, as the powder needs time to take effect and dehydrate the insect.

The timeline for your cockroach infestation to completely disappear can vary between a few weeks. It may take this long because the cockroaches have to find the DE and crawl through it. If you place the powder somewhere that the roaches do not frequent, then the effects may take even longer.

Once you have placed the treatment, don’t be surprised if you see roaches coming out into the daylight more. As they become dehydrated, their desperate search for water leads them to look in even the most unlikely places to satisfy their thirst. While it may seem like the infestation is getting worse, this is a sign that the DE is working.

Using DE to Kill Cockroaches

Dead Roach on Counter
Here are the steps to using DE to kill or prevent roaches in your home.

Applying diatomaceous earth for roaches is very straightforward. Just follow these steps and get ready to say goodbye to your insect infestation!

1.   Clean, Clean, Clean!

Cockroaches don’t like pristine conditions, so this is the first step to make your home an undesirable environment for insects. Don’t just do a superficial cleaning; get down into your home’s cracks and crevices and give everything a good cleaning.

This process will also allow you to look for any openings in the walls or foundation where the roaches might be entering your home. Even if you always keep an immaculate kitchen, the cockroaches may be gathering in the forgotten areas of your basement, so make sure to check everywhere.

While you’re cleaning, make sure everything is left dry. If there are damp areas – which cockroaches love! – the diatomaceous earth will not take effect there. Take some time to treat leaky pipes or mold problems before applying the DE for the most effective results.

2.   Apply the Diatomaceous Earth

Leave a light dusting of DE anywhere you have seen cockroaches. Make sure not to block their pathway or holes, but instead sprinkle the powder over the area. If you make the layer too thick, the cockroaches won’t be able to crawl through it and avoid it altogether.

Ensure you apply the diatomaceous earth in any crawl spaces you have. Even if you haven’t seen them there, it doesn’t mean they don’t use the space. Also, the DE works as a preventative, so it cannot hurt to leave it in potential cockroach friendly areas.

Don’t forget to apply the powder in critical areas around your kitchen. Leave some under the stove and fridge or where crumbs usually fall and get forgotten.

Types of Applicators

There are several different methods to apply DE around your house.

Leaving the diatomaceous earth in hard-to-reach crevices can be difficult. Plus, you don’t want to spill the DE or get it in your eyes accidentally. Thankfully, three main types of applicators make this process as simple as possible for you.

Duster: Dusters work like a caulking gun and is perfect for applying DE along cracks, crevices, and tight areas under furniture. This tool lets you spread the powder in a controlled manner, so it doesn’t get all over your house.

Scoop: You can use any scoop lying around your house or get a new one just for diatomaceous earth. Either way, this tool will let you easily apply the DE to targeted areas around your home. It may be harder to get a light coating with the scoop, so use it in higher-traffic areas like near garbage cans.

Sifter: If you have a sifter in your kitchen, you’ll know just how this works. You’ll distribute the powder just like you would apply a soft layer of powdered sugar to a fresh batch of cookies. This tool is ideal for treating expansive areas as it will give you an even coverage in the whole room.

3.   Remember the Exterior

You can use diatomaceous earth both indoors and outdoors for the most effective roach treatment. Leave DE along exterior openings and cracks to prevent the cockroaches from ever getting into your home. You can also use it around any non-edible plants in your yard.

4.   Leave it Be

Leave the DE where you left it for about two weeks. If you notice that the cockroaches haven’t touched the powder in certain areas, you can leave it alone for as long as you want to prevent insect infestations.

However, if the diatomaceous earth gets wet, you will need to apply. Also, if you have a massive cockroach infestation and the DE has been moved or used up, you will need to add more.

Don’t be afraid to maintain a constant supply of DE around your house. This treatment will give you an extra level of protection against future insect invasions.

5.   Clean-up Made Easy

Once you’re done treating the cockroach infestation, or if you need to remove wet diatomaceous earth, you can easily clean it up with a broom, vacuum, or damp paper towel. Remember to wear a mask, so you don’t breathe any of the DE. Other than that, the clean-up is just the same as any other household mess.

Types of Diatomaceous Earth

DE mixed in water
There are several types of DE you can use to treat your home, with food grade being the safest.

There are a few different types of diatomaceous earth that you can buy. While they all come from the same product, some forms of DE can be incredibly dangerous to humans. As such, make sure you buy the correct products for your home and family.


Food-grade is the safest form of DE, as it only contains 0.5-2% of crystalline silica. This type is the diatomaceous earth you will find in toothpaste and beverages. It is generally safe for consumption, and many agricultural and food companies use it to prevent lumps in powdery products.

While this is safe for human consumption, it is still deadly to insects. If you have pets or children running around your home, this is the safest option for everyone in your house – except the cockroaches, of course. You won’t have to worry about your toddler and pets finding and eating it.


This type of DE has around 60% of crystalline silica, making it extremely dangerous for humans and their furry friends. Manufacturers generally use the filter grade diatomaceous earth to make dynamite and water filters in pools.

Of course, if only 2% of silica will kill cockroaches, the filter grade DE will definitely kill any pests. However, it is not safe to have it exposed to humans, so stay away from this type of DE.

DE with Insecticide

Some companies combine diatomaceous earth with pesticides to make the food-grade DE more effective. While this will kill the cockroaches quickly, it will not be as safe around children and pets.

However, if you live alone or with adults, this could be a more potent option for your insect infestation. You could also use this type of DE on plants or outside, except for any edible plants (like tomatoes or mint).

Combining DE with Other Treatments

Roaches leaving home
You can combine DE with other treatments to get roaches out of your home.

The best treatment for any cockroach infestation is the combination of multiple methods. Use natural repellents, like chrysanthemum plants or citrus sprays to keep the cockroaches out of certain areas.

As they leave those areas with repellents, make sure you have the diatomaceous earth waiting for them in your home’s other rooms and spaces. Combine the DE with boric acid, which you can form into deadly doughy balls. However, just like other insecticides, boric acid can be dangerous to children and pets.

Another option is to put cockroach traps in hidden areas and use the diatomaceous earth in more open, exposed areas of your home. You can also use insecticide spray outside or inside wall crevices where pets and children won’t touch or eat the chemicals. Keep the DE as a safe treatment in your kitchen or common areas and as an effective preventative.

Potential Dangers

We’ve already discussed the different types of diatomaceous earth and their level of safety for humans. Ensure you do not buy the filter-grade DE, as it will be toxic for everyone exposed.

For the safety of your family and pets, use only food-grade diatomaceous earth. Any other form could harm your lungs if you are exposed.

Of course, since diatomaceous earth is a powder, there is a low risk of any form irritating your eyes, skin, or lungs. It is a very fine powder and could quickly get blown into your eyes or mouth. To completely protect yourself, make sure you wear a mask, eye protection, and gloves as you set out the traps for the cockroaches.

Wrap Up

If you are looking for a safe, cost-effective way to free your home of nasty cockroaches, diatomaceous earth is your answer. Since the food-grade DE can is safe for use around children and pets, it is the perfect tool to use in your kitchen and other open areas of your home.

Ensure you adequately protect your eyes and lungs while applying it, and let it sit for as long as necessary. It’s that easy! The best part of DE is that it will retain its potency indefinitely if left untouched, making it a great preventative tool against cockroaches.

Managing Editor & CEO Jack has been writing as a contractor and for businesses for over 10 years. He owns his own home, and has been doing his own pest control since he bought his first house.

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