Killing Roaches Part 3… Eradicating Roach Colonies With Diatomaceous Earth
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.
NOTE: 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.
I 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!
The Go-To Guy!
Did you enjoy reading this post? Buy me a nice cup of coffee to fuel my late night writing sessions and keep the content flowing!
Tags: boric acid, cockroaches, diatomaceous earth, killing cockroaches, killing roaches, mint oil, orange oil, roaches
March 1st, 2008 at 11:33 pm
Andrew, I feel more empowered to fight my personal roaches after reading your blog…thanks for the detailed account. My roach problem showed up about a year and a half after we moved into our house. I don’t know how they got in…I’m thinking via Costco boxes, or maybe my cleaning lady. It was in the middle of winter they started appearing. I’m thankful the infestation is in a very limited area (mainly the “wet and greasy” side of my kitchen where the sink and stove are) and I only see at most 3 or 4 usually when I turn on the light, sometimes none at all. I think the important thing is “constant vigilance” to keep them under control. Your techniques are great. Thnks again.
March 2nd, 2008 at 9:46 am
Kia,
I’m very happy to hear that my ordeal has given you hope. It’s not 100 percent over (we probably won’t have any hope of that as long as the ‘cat lady’ lives above us) but we’re no longer spooked by every movement we see out of the corners of our eyes.
I encourage you to do 3 things, clean your stove like you’ve never cleaned it before (if it is free standing, pull it out and degrease the back and underneath), get some roach gel (if you can find a place that will sell you professional grade gel – get it) and place a bead of gel along all of the hidden edges of the stove where the roaches might walk (along the bottom edges, corners in the back, door hinges, etc.), and then seal every crack and crevice you find (around water and drain pipes, along trim and mouldings, cracks in the floor, switch plates and electrical covers too.)
Sealing up the pathways where they move is extremely important. I saw the biggest change the day after I caulked all of the walls and cabinets. If you don’t know where they are coming from, place glue traps along the walls in the places you suspect and see where you catch the most.
Another thing we started doing was spraying the counter tops at night with a mixture of 1 tablespoon of Tobasco sauce in 1 quart of water. Apparently the roaches don’t like the pepper and will avoid surface where it is present. We spray it around pretty generously in the kitchen at night to make the place as unpleasant for the roaches as possible. The spraying can give you a little sneezing fit while the mist is in the air, but the mixture is diluted enough to be unnoticeable once it settles and dries.
Please leave a comment again when you’ve had a chance to test out some of these methods. Field reports are the best information.
The Go-To Guy!
September 4th, 2008 at 1:33 pm
I get like one freaking GIANT roach looking thing avery couple of days? What do I do? They’re like 2 inches long, a reddish color and too big to squash unless you want to mop them up????
September 4th, 2008 at 4:04 pm
Mark,
Sounds like you are probably dealing with an American Cockroach.
The good news is that they don’t reproduce and mature as quickly as other roaches, so you are less likely to get over-run with them.
The first step is to try and discover where they are coming into the building and seal off the entrance. Cracks along baseboards and holes around plumbing pipes are good places to start.
Check for water leaks as well. Access to water is one of the main things that attracts roaches. Then, dust diatomaceous earth along baseboards, under appliances, and anywhere else where you think they might be traveling.
Even if you stop new roaches from getting in, you will need to make sure and get rid of any that are already inside. To catch them, place glue traps along the wall edges that they are most likely to be traveling along. When the traps fill up, toss them and replace. Keep this up until you stop catching any.
Let me know how it goes for you,
The Go-To Guy!
September 9th, 2008 at 6:35 am
Andrew: Thanks a LOT for your site, it’s been really helpful in convincing me that roaches can be conquered. But do you have any suggestions for where I can buy a bottle with a cone-shaped tip like the one you used?
September 9th, 2008 at 11:31 pm
Sarah,
You are welcome.
You can get Plastic Squeeze Bottles
at Amazon.com. You could also check your local craft store.
I re-used a bottle from some Boric Acid I had bought and used up.
Please come back and leave a comment when you get your problem under control and let everyone know what worked for you.
The Go-To Guy!
May 26th, 2009 at 10:44 pm
Andrew: I was wondering if anyone has ever said if you can use this product for carpet Ants. I just killed a huge ant with wings on it. At first we just had black ants and we sprayed all around the house inside and out and now I have this big ant that looks like a bee but I went on line and looked up the pictures to make sure that is what it was. Sure enough that is what it is. So I am wondering if this would be a great product for carpet ants. Scared out of my mind.
July 25th, 2009 at 1:22 am
I have noticed that washing my counters nightly with bleach and the same with the inside of the cupboards usually on a weekly basis has helped with keeping my roach problem bearable, how ever after reading your article I have more to try to come as close to eliminating my roach problem as I can get since I live in an apartment complex good thing we didn’t through out the DE after filling in our pool.
July 27th, 2011 at 5:27 pm
well for all you new yorkers out there or people who have a hard time finding it just go to a pool store or a hardware store even cvs sav-on and rite aid have pool supplies and you get a huge box of it much better then a little box from a bug killing company.
August 4th, 2011 at 1:01 am
I know this last post from Joy was awhile ago but Oh Lord I hope she didn’t use the DE from the pool in the house! Only use the “Food Grade” D.E.
August 6th, 2011 at 1:17 am
If you’re wondering where to get a squeeze bottle to put your diatomaceous earth or boric acid in, try a beauty supply store. The squeeze bottles colorists use for dyeing hair work great. Just be sure to get one that is soft plastic and easy to squeeze so the powder comes out easily. The bottles that are made of harder plastic aren’t as easy to squeeze. Most of these bottles don’t come with caps, so I put slip a toothpick into the hole of the cap to keep moisture out. Good luck getting rid of your pests. I live in an apartment building where I have to be constantly vigilant because of the neighbors.
August 21st, 2011 at 8:39 am
I know this is an old article, but after reading Joy’s response, I had to make a comment for anyone else who may read this article.
I am assuming the DE that Joy is using is POOL GRADE if she was using it for her pool. This is NOT the kind you want to use. You want to use FOOD GRADE DE. POOL GRADE DE is treated, which changes the chemical composition of the DE, so make sure you get FOOD GRADE DE ONLY!
September 13th, 2011 at 2:05 pm
Joy,
The DE you use in pool filters is not quite the same form of DE which Andrew is likely referring to. It can be harmful. The type used in pool filters is processed using high heat (calcining) …. which forms a much more crystalline version of DE. This more crystalline form can be harmful to Humans and animals, though is likely more harmful to arthropods (insects) as well. The type Andrew is likely referring to is classified as “Food Grade” DE. This form is processed using a passive drying processes which does not alter the physical form of the DE. It is safe for consumption and would not pose much of risk as a lung irritant.
December 3rd, 2011 at 1:44 am
Jim,
You are correct. I use food grade DE or grades specifically labeled for pest control use.
Thanks for adding this clarification.
Andrew
December 3rd, 2011 at 1:47 am
Tami,
You are correct, thanks for sharing this information. I actually didn’t come across the availability of pool grade DE until long after I wrote this (not too many people have pools to maintain in Manhattan – at least not in the circles I traveled in, anyway.)
Andrew
December 3rd, 2011 at 1:48 am
Nina,
Great tip. Thanks.
Andrew
December 3rd, 2011 at 1:50 am
Tim,
The pool filter DE is NOT the same. It has been processed in a way that alters it significantly. Only use food grade DE or DE that is labeled for pest control purposes.
Andrew
December 28th, 2011 at 1:37 pm
Hi. I have huge amount of cockroaches in my kitchen. tried everything from superstore and cleaning like insane. After i saw your blog tried DE but there is no impact on roaches at all.its been two days.please help how can I get rid of cockroaches. they are smaller in size and so many of them
January 27th, 2012 at 10:11 pm
Nayma,
Getting rid of them involves cutting of their food sources, getting rid of places where they can nest, and blocking their ability to move in and out of your walls.
Based on your comment on their small size, they may be oriental roaches or recently hatched (or both.) That means they can squeeze through incredibly small cracks. So, the first thing you have to do is fill every single gap and crack in your kitchen.
Most kitchens have huge gaps around the plumbing pipes under the sink. Check yours. There might be a metal ring around the pipes to visually cover the holes – pull them back and see of there are cracks and gaps around the pipes. Get some expanding foam insulation from the store and fill the cracks and gaps around the pipes.
Next, get some clear silicon caulk and fill every single crack along the baseboards in the kitchen. Then, get some insulating pads to go behind the switch plates and wall outlet covers (these are designed to keep out drafts, but they work for roaches too.
Finally, get some glue traps and place them along the walls on the floors and along the cabinets too. These will trap the roaches as they move around and help you to find out where they are coming from.
I’m sorry to hear about your problem, but I know you can stop those nasty critters. Good luck,
Andrew