How To Use Diatomaceous Earth At Home

There are many methods that people use for pest control, but how to use diatomaceous earth varies depending on situation. We explain it all!

How to use diatomaceous earth


Many people steer away from pesticides. If only there were something that had little to no risk! That’s where diatomaceous earth comes into play. It’s virtually harmless, natural, and diatomaceous earth works as a pest control option as soon as you apply it. Knowing how to use diatomaceous earth can help to make your life much easier – and who doesn’t want an easier life?

Diatomaceous earth, or DE, is completely natural as it’s made of fossilized aquatic remains that are ground to a fine, smooth-textured powder. It’s a bit irritating to humans and animals since it’s dry dust that can get in your eyes or make you cough, but the food-grade form is non-toxic and is used to fight off insects in your home.

Let’s take a look at the good and the bad of diatomaceous earth and how you can start using it in your garden. You’ll probably use this to protect against pests a lot!

What Is Diatomaceous Earth?

How to use diatomaceous earth
Knowing how to use diatomaceous earth in the garden and home is useful. Source: draggin

Diatomaceous earth is a white powder made of fine particles. Since it looks like dust, it’s kind of hard to believe that they’re the fossilized remains of aquatic organisms! The organisms were diatoms, a specific form of phytoplankton that is a type of algae. Their cell walls were made of silicon dioxide.

Over hundreds of years, diatoms built up in bodies of water and became fossilized over time. They formed a siliceous sedimentary rock called diatomite that can easily be ground into a fine powder, and that’s the powdered form we refer to as diatomaceous earth. 

How Does Diatomaceous Earth Work?

But how will diatomaceous earth kill insects if it’s just a powder? We can’t see it or feel it as we have much tougher skin that isn’t damaged by it, but these microscopic particles of diatom shell have sharp edges that can cut into an insect’s exoskeleton as they walk over it.

The diatomaceous earth then sticks to the insects, and because the powder is so dry, it will absorb the moisture from insects (such as fats and oils) and cause them to dehydrate. It sounds gruesome, but it’s just nature working the way it was intended.

The downside of DE is that it has to be dry to be effective. If you apply it to your garden and it rains, or you water your plants, it will no longer be effective until it fully dries again. 

Types of DE

You should always use food-grade diatomaceous earth. This kind of diatomaceous earth is purified and sterilized, doesn’t have any harmful additives, and is considered amorphous silica that’s generally recognized as safe by the FDA. 

Food-grade DE can be found in various products outside of gardening, such as toothpaste, beverages, skin care products, animal feed, medications, rubber, and many other things. Some claim it has health benefits, although it’s best to confirm with your doctor before any health use. Still, it’s completely safe to use in both your garden and in your home. It is used for preventing insects from eating livestock feed and can be found at your local feed store or garden center, often labeled as diatomaceous earth for pest control. Buy diatomaceous earth that is labeled as feed grade DE or food-grade, not as pool grade DE!

There’s another type of diatomaceous earth that isn’t as safe. This kind is crystalline silica, which may cause lung disease, inflammation of respiratory systems, and potentially even cancer if it’s inhaled. This kind of DE can be found in very few products meant as pesticides. Sometimes, it’s sold as pool-grade diatomaceous earth and is used in swimming pool filters or other non-potable water filters. Pool grade DE has been treated with high heat to crystallize it rather than to leave it in its amorphous form. The labels will usually have a warning label to let you know that it’s not safe for human consumption. Avoid any diatomaceous earth that describes itself as crystalline silica.

Benefits Of Using DE

Diatomite is mined and then ground to produce diatomaceous earth. Source: James St. John

The benefits of diatomaceous earth outweigh the drawbacks by a long shot. Diatomaceous earth can kill almost any insect with an exoskeleton, including ants, aphids, bed bugs, cockroaches, flea beetles, fleas, carpet beetles, and spider mites. It can even kill snails and slugs, too. Diatomaceous earth will only kill the adults or larvae of these pests, not the eggs, but you can get rid of the insects in your garden and home by disrupting the lifecycle and killing adults before they can lay eggs.

You’ll have fast results when using diatomaceous earth because it starts working instantly as long as it’s dry. Pests will walk across it and begin to dry out. It can take up to twenty-four hours for the bugs to die, but the dehydration process begins as soon as they make contact with the powder. 

A benefit of food-grade diatomaceous earth is that you can use it inside and outside of your home. You can apply diatomaceous earth directly on ants in your home, along baseboards and windowsills, on the soil outside, on the leaves and branches of plants, or wherever else you need it. 

If your pets have fleas, you can apply diatomaceous earth to the carpet, rugs, and pet beds to eliminate the adult fleas and prevent them from laying more eggs. Just be sure to keep your dogs or cats away from their bedding while you treat it since the dust can be an irritant when inhaled. Leave the diatomaceous earth in place for at least 8-12 hours before thoroughly vacuuming it up.

Food-grade diatomaceous earth is non-toxic to humans and animals, although it can be an irritant. The risks are minimal, so you can feel good about using it in the house with animals and children.

Drawbacks Of Using DE

The biggest drawback of diatomaceous earth is that it can be an irritant when inhaled or when it gets into mucous membranes. It’s generally considered to be safe to use around kids and animals, but breathing it in can cause lung irritation, shortness of breath, and coughing. It can make your skin and eyes itchy and dry, too. 

Remember, food-grade diatomaceous earth is the safer version of DE that you should always use. Non-food grade forms meant for pool or other uses are comprised of crystalline silica, and they have many more potential health risks than the food-grade version does.

Another annoying thing about DE is that it has to be dry to be effective. Daily watering, heavy dew, and frequent rain can make using DE a bit of a hassle. It won’t be as much of an issue inside the house, but outdoor garden use requires a bit of forecast checking and planning in advance.

Since diatomaceous earth can rid you of many insects and garden pests, it’s worth mentioning that it may be harmful to beneficial insects that act as pollinators, including bees and butterflies. You can easily avoid harming them by paying attention to how and where you apply the powder. Pollinators almost always land on flowers, so avoid putting DE on any part of the flowerhead. 

If you’re worried about accidentally hurting your pollinators, take a few days to observe how they move around in your garden. Take note of where they land, which plants they gravitate toward the most, and what time of day they’re most active. Minimize the risks by avoiding certain plants and flowers.

How To Use Diatomaceous Earth

Potato plants treated with DE
Diatomaceous earth can be dusted or sprayed onto plants. Source: paix120

Using diatomaceous earth is super simple, but there are a few things you should know before you start applying it to your home and garden. Always use food-grade DE, wear protective clothing and gear when applying it, and always read the label before you start using it. 

The dust is an irritant that can cause coughing and breathing issues if you inhale it and will make your eyes and skin itchy. Wear a dust mask, safety goggles, long sleeve clothing, and gloves when using it—even if it’s food-grade—to prevent yourself from inhaling it. Keep children and pets out of the area until the dust has settled completely.

Even though most DE is the same, you should still read all the label directions before you use the product, as some brands may have different directions than others. This is especially important since there are other forms of DE that aren’t food-grade. If you accidentally bought the wrong one, reading the label will stop you before you apply diatomaceous earth of the wrong kind!

How To Use DE In The Garden

Since water softens amorphous silica and renders diatomaceous earth temporarily useless, it can be somewhat tricky to use in certain situations, but that certainly doesn’t mean it can’t be used at all! Make sure you don’t apply it when the ground or plants are wet and keep it away from areas that collect runoff water. Unfortunately, this means it’s not very effective around plant roots, so you’ll need to use a different method to get rid of bugs that live directly in the ground around your plant.

To apply diatomaceous earth when it’s dry, you can simply sprinkle it where you need it or use an applicator. You can sprinkle it on plants, on the ground, on the patio, in obviously infested areas, or wherever you need it. An applicator can be a sifter or a duster. Sifters will help you get an even application, and dusters will make it easier to apply a fine layer to the leaves of plants.

It’s also possible to mix diatomaceous earth with water and spray it as a spray. This is the easiest way to adhere DE to hard-to-reach areas of plants like underneath leaves and on branches. Wet diatomaceous earth will stick to the plants and become effective once it dries out. The label on your bag may have specific measurements to make a spray, but if it doesn’t, four tablespoons per gallon should do the trick. 

If you choose to apply diatomaceous earth using a water application, make certain that your specific brand recommends applying DE in this fashion. Some versions are not as finely-powdered as others and may include larger natural particulate than others. This can clog your sprayer and make it hard to re-apply.

Soil application can be tricky, particularly if you use a watering method that soaks the ground around your plants. People using soaker hoses may have a leg up on this process, however. If you get your soaker hoses in place permanently, then top with a thick layer of mulch, you can apply diatomaceous earth on top of the mulch. The mulch can act as a natural moisture barrier and keep your diatomaceous earth drier and more effective as a result. 

How To Use DE In The Home

Sprinkle dry diatomaceous earth in areas where you see pests the most. This can be under appliances, on windowsills, under beds, along the door frames or baseboards, or wherever else you see it in the house. Work it into crevices between floorboards, too. If you have children or pet animals, you should keep them out of the area until the dust has settled and keep an eye on them to make sure they don’t try to eat it. Avoid application near the heater or air conditioner vents to prevent the powder from becoming airborne when they kick on.

Use a fine flour sifter or a duster to evenly apply DE on carpets and rugs if you’re treating fleas, ants, or other hidden insects you want to get rid of.  DE will last a long time indoors, so you won’t have to reapply it often. When you’re done treating the floors, vacuum the dust and dead bugs up.

Apply diatomaceous earth to beds to treat bed bugs, pet bedding, blankets, cushioned furniture, or wherever else you find pests hiding. Be careful when you treat these areas as the dust can be irritating. Don’t use the furniture or blankets until you’ve completed the treatment and thoroughly washed all items, or vacuumed all surfaces.

The wet application isn’t viable to use indoors, although you could probably use it in garages or on tile floors. You’ll need to allow the area to dry on its own so the diatomaceous earth can dry, so it’ll be messy and humid for a bit – and that isn’t ideal inside the home. Stick with dry application methods indoors.

Frequently Asked Questions

Working DE into floorboards
Lay down some DE and then use a broom to work it into gaps between floorboards. Source: Claire CJS

Q: Can you mix diatomaceous earth with water and spray it?

A: Yes, you can! You can add several tablespoons to a gallon of water and use it to apply diatomaceous earth in hard-to-reach areas. It will easily stick to leaves and stems and become effective once it dries completely.

Q: How long does diatomaceous earth take to kill?

A: Diatomaceous earth begins working as soon as insects walk over the powder, but it can take up to twenty-four hours for them to die. They die by dehydration which requires a bit of time to happen.

Q: Is diatomaceous earth harmful to pets?

A: DE can be an irritant if your pet inhales it or if they come into contact with it. They may experience breathing problems and itchy eyes and skin. While food-grade DE isn’t considered toxic, it can be quite irritating and uncomfortable, so it’s best to keep your pets out of the area when you’re using it.