Killing Roaches Part 3… Eradicating Roach Colonies With Diatomaceous Earth

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In my earlier posts about my roach killing expedition, I mentioned my discovery of Diatomaceous Earth. This non-toxic powder has the ability to kill roaches (and a whole bunch of other things) without poisoning them. It is microscopically abrasive and cuts and scratches the roaches inside and out. Since it’s not a poison, it doesn’t lose potency over time. So, one good application will last a long time.

Safe, non-toxic pest control - Eartheasy.comNOTE: Only use food grade diatomaceous earth or a product specifically labeled for pest control. The type of diatomaceous earth used for swimming pool filtration SHOULD NOT BE USED!

With a baby in the house, I was looking for non-toxic options for long-term use. This seemed like a very good product, so I started to hunt around for a local supplier. In New York City this wasn’t readily available (I didn’t have time to search around at gardening centers) so I ended up ordering it from Amazon. They also had a mint oil based non-toxic spray, so I got a couple cans of that as well.

When my 4 pound bag of Diatomaceous Earth arrived from Amazon I immediately set out to using it. I discovered a few things about how to best use Diatomaceous Earth in your roach killing efforts.

The first important thing to note is that, while Diatomaceous Earth is not poisonous to humans, it IS an irritant. It will get on your skin and dry it out like a mudpack. It has a mild, but noticeable, odor and it can irritate your eyes.

The second important thing to note is that Diatomaceous Earth will easily disperse in the air and form a cloud of fine particles that hang there a long time and then settle on everything in the room. This is not necessarily a bad thing!

Where To Apply Diatomaceous Earth For Effective Roach Killing

The goal with a product like Diatomaceous Earth is to get the roaches to track it back into the walls where it kills the roaches in the nest. A common application is to dust it under sink cabinets, stoves, refrigerators, and along baseboards. It is also good to spread it around outside if the roaches are coming from there (the powder in an outdoor application needs to be re-applied after rain.) I wanted to be even more aggressive.

If individual roaches tracking the Diatomaceous Earth into the walls was a good thing, I reasoned that coating the interiors of the wall with the powder would be even better – like a giant roach roadblock in the wall. I decided to drill small holes in the space between the wall studs in my kitchen and bathroom and blow the Diatomaceous Earth inside to coat the interior surfaces. A little drywall patching and paint afterward and I could relax in my own home instead of constantly scanning for roaches.

Applying Diatomaceous Earth For Roach Control

I got a plastic bottle with a cone shaped tip like those used for Boric Acid. Once filled with Diatomaceous Earth, I set out to dust under the refridgerator, stove, and along the baseboards in the kitchen. I tipped the bottle and squeezed it quickly to ‘puff out’ a little powder.

Safe, non-toxic pest control - Eartheasy.comI was concerned early on that the Diatomaceous Earth would clog up the bottle, but the fine powder dispersed nicely. However, I got a little aggressive trying to blow the powder back under the fridge and, when I looked up, I noticed the cloud of dust hovering in the kitchen.

Blowing the dust inside the walls turned out to be a much easier task than originally anticipated. Only a small hole was needed to get the Diatomaceous Earth inside and some vigorous work with the bottle created a cloud of dust inside the walls which coated every surface with roach killing powder – sweet!

IMPORTANT NOTE: Wear a mask when applying Diatomaceous Earth.

One nice thing is that the dust clings easily to many surfaces. So, the sides of the stove and lower cabinets are now roach death traps. In fact, the vast majority of the kitchen surfaces are now inhospitable to roaches.

I was pleased to discover that the following day the number of roaches spotted in the kitchen had declined noticeably. And, I saw a couple of them moving slowly with a coating of the Diatomaceous Earth on their bodies. I found a few more in the glue traps around the kitchen coated in dust.

Unfortunately, new horror kicked in when I realized the roaches were moving into the living room looking for new hunting grounds. The bedrooms were sure to follow. This was not good.

New glue traps were quickly placed in the major roach pathways in the living room and Diatomaceous Earth was dusted under some of the larger furniture and along some of the hidden baseboards to keep the roaches contained.

The second day after applying the Diatomaceous Earth, we had almost no roaches in the kitchen at all. I did the usually rattling of dishes and opening of cabinets designed to flush the roaches out of hiding and found nothing. This was all the more shocking given the fact that I had fallen asleep leaving dishes in the sink and before taking out the very full trash. While washing the dishes, one lonely baby roach came out of hiding and I quickly dispatched him with a shot of my mint oil spray!

If you have any tips or special techniques for killing roaches using Diatomaceous Earth, leave a comment below and let everyone know!

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Andrew Seltz

I was born in Michigan, raised there and in Tennessee, and have since lived near Orlando, in Chicago, and now in New York City. I produce videos and websites for a living and am married to a beautiful, generous, loving woman who also happens to be a talented actress -

63 thoughts on “Killing Roaches Part 3… Eradicating Roach Colonies With Diatomaceous Earth

  • August 20, 2013 at 12:17 pm


    I used each in sequence and did not mix them beforehand.

    Boric acid works as both an abrasive (like DE) and a stomach poison. There is significant overlap as far as what they do to control pest, so you would be fine to use either one by itself. I liked the way the DE dispersed and clung to surfaces and wanted the extra stomach poison aspect of the boric acid too.

    Good luck,


  • October 24, 2013 at 1:28 am

    I just purchased some DE to use around my mobile home. After a neighbor moved a trailer from next door to us, we became INFESTED….beyond infested. We’ve had multiple sprayings, bombed a few times….nothing has worked. Also, my elderly mother lives with me as well as a few pets and I didn’t like the idea of all those chemicals in the house. I started researching alternate Ideas. I haven’t tried the tobasco or the herbs yet but I’m going to, but I have started today with the DE. Unfortunately, as much as it needs it, I cannot plug our caulk holes and cracks….I live in an old mobile home that is older than I am….it is one of those places that needs LOTS of work, things like small holes are nothing. I have huge holes such as the bottoms of cabinets rotted out, etc. I don’t have the funds to fix them myself and my landlord won’t. I am going to have to hope I can control them when they come in, and your extensive article reassures me that at least I didn’t waste my money on DE 😀

  • March 31, 2014 at 4:14 pm


    Great info altogether, been reading up along the net for all kinds of ideas and like what I read here. Now to my dilemma…

    Former Cali resident with no roach problems I couldn’t handle, now in Texas where I’m just grasping the issues of roach infestations in a desert environment. House is mainly sealed up externally Looking at sealing internally as well (not there yet). Problem is not an internal issue rather an external one. I have no nesting internal and house is sterile at all times, garage too. At night they come out of the desert sands and migrate towards the house and find ways in. Previously, pesticides have been used externally and roaches that do make it in die that same evening, close to where they enter.

    I’m looking at using DE from here on out and I’m an ex-pool service technician. I know DE very well as a filter additive and how dangerous it is. Question is while searching across the net I feel I’m reading crossed messages. While I understand the importance of using food grade DE indoors, I don’t understand why pool grade couldn’t be used outdoors?

    My reasoning, I don’t have a garden or pets outside and from reading DE differences, pool grade has a greater percentage of silica than food grade(i.e. 2% vs. 60%). Now if the silica is cause of the irritant, wouldn’t a higher percentage be better for eradication? I’ve read elsewhere that pool grade DE does not affect roaches, but I can’t see how that’s possible. I guess the only thing that would occur is that they would die quicker?

    Just curious since I can purchase pool grade much cheaper the food grade if I plan on using it in desert sands. I mean really, would you pour food grade DE out in the desert (:

    Thanks in advance

  • July 12, 2014 at 2:03 pm


    I just discovered a roach in my bathroom last night–I’ve lived all over the US and I’ve never experienced this. I’ve lived in this apartment for 7 years and this is the first time I’ve ever seen anything like it. I mean, when everyone else was getting infested with stink bugs we had nothing at all. It was crazy.

    When I first saw it I wasn’t sure what it was. It was about an inch long. Not sure what kind of roach that would be. Probably American?

    Anyway, I literally went into panic mode, which was made worse when my teenager came home around 1 am and said there was one downstairs in the hallway. I grabbed my car keys and ran to Walmart and got DE. I should have grabbed some clear caulking but my mind was so focused on creepy crawlies that I never thought of it. I didn’t sleep at all. I’m pretty meticulous about being clean, but I totally emptied out my kitchen, pulled out the stove and refrigerator, and poured the stuff right into every single crack I could find. There are still some large holes under the sink and behind the stove, but I used Gorilla Tape as a temporary stopgap till I can call the building manager on Monday. Why do these things always happen on a weekend???

    This morning, I went into hallway armed with the DE and a measuring cup. Not even a spray bottle. I sprinkled it all along the walls and baseboards and even on the steps. Later this afternoon I’m going down to the basement, which is a big wide open area, and I’m going to treat that, too.

    And then we’ll see what happens on Monday when I call them.

    DE is the same stuff they use in flea and tick powder for pets. I have two cats, and the way I see it is if they accidentally get any on themselves, well, it’s a two for one deal! Kill the fleas and ticks, too. Actually, my one cat is how I found the roach. She’s an indoor cat, so since she can’t hunt rodents she hunts bugs. She’s given me decapitated spiders as “presents”. Well, she went right after this thing and terrorized it till it found whatever absurdly small hole it went into.

    I’m trying to figure out where they’re coming from, but my best guess is that they’re in the basement. There was a sewage issue about 6 weeks ago and if they didn’t take care of that properly (knowing them, probably not), well there ya go. It may just be a coincidence, but one of my neighbors just moved out as well and they were not the cleanest people in the world. They have not been back to clean their apartment and they’ve been gone for almost a month. I heard that they paid an extra month’s rent so they have till the end of July.

  • August 22, 2014 at 10:33 am

    The first place to check for entry points is water and drain pipe penetrations in the walls. Common construction practice is to cut the holes a little big and put a trim cover around the pipe to cover the gap. These covers are not sealed and leave plenty of space for roaches to enter and exit the wall. They can travel along the water pipes through the holes drilled in the framing. I recommend using spray foam insulation to fill the gaps (and you might dust a little DE in the wall before you seal it up.

    Apartments are tough. Your neighbors have a huge influence over the pest population. When someone moves out, pests go looking for a new food and water source. Any gaps in a shared wall can create an entry point. So, sealing gaps and cracks is a good first step.

  • March 2, 2015 at 2:42 am

    I am trying to figure out if there is a safe way to use DE to get roaches out of the microwave

  • March 26, 2015 at 12:55 pm

    I wouldn’t recommend dusting DE inside a microwave. It will mess up the motors and the cooling fans will blow it around every time you turn on the microwave.

    If they are inside the electronics, you will probably need to open it up to clear them out. If the microwave is mounted over the stove, you’ll have to take it down. If you are not comfortable around electronics, or have trouble lifting and moving things, enlist help.

  • May 28, 2015 at 8:20 am

    Hi Andrew, so glad I found this page! I have only seen one live roach(which was caught in spider web in garage) but am finding droppings, similiar to mice droppings (only smaller) on bath towels. The towels are in an open rack… I have set traps for mice thinking that may be problem, only to find peanut butter gone in the morning with trap still set. So my question is if its normal to see the droppings & no roaches? Also found them(droppings) in a few drawers which I emptied & cleaned, then put roach bait & glue trap inside but of course no activity there. Im wondering if theres another critter or bug around or are the roaches hiding well? Thanks!!

  • June 28, 2015 at 12:47 pm

    Thanks for this post, Andrew. My girlfriend has similar roach problems and after several attempts bug bombing her place (which I was highly opposed to) I convinced her to give DE a try. I’ll let you know how it goes, but we’re just starting this war on those little vermon.

  • August 19, 2015 at 7:13 pm

    Thank you for the info about DE. We have an asthmatic in the house…do you think if I apply it around the house while he is out for a few hours, that it will bother him?

  • August 30, 2015 at 3:23 am

    I’m a pest controller in London and have a problem with American cockroaches infesting kitchen drain sumps. We need to avoid contaminating the drainage water system with our usual range of insecticides ( stated on the label ) so I was thinking about DE applied beneath the drain covers and down the sides above the drain . We don’t want to excite the adults into movement to other more obvious areas and it’s hard work lifting the covers so we don’t often have access . Any ideas please ?

  • September 21, 2015 at 3:24 pm

    Once the DE settles, you shouldn’t have problems. Just make sure to avoid applying it to areas where there will be air disturbance. Avoid air vents, etc. so that you don’t stir up the DE after it has settled in place.

  • September 21, 2015 at 3:33 pm

    DE is not going to be a good solution for wet areas. The moisture will cause the dust to cake and then it will not stick to the roaches as they walk over it.

    I have not encountered a directly similar situation, so I do not have a specific recommendation. You will likely have better results devising a bait trap that will adhere to the underside of the drain covers and deliver a conventional insecticide.

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