Tip #22

Boric Acid is the Best Roach Killer

Written on January 18, 2013 by , updated on July 30, 2014

WARNING: Any product that will kill a roach, is usually somewhat dangerous to humans.Therefore, be mindful of pets, babies, and tenants when treating your rental property.

Boric Acid

I’ve tried almost every roach-killing chemical out there and the winner seems to always be Boric Acid – which is an inexpensive do-it-yourself product that can be found at most big grocery stores and all hardware stores.

In my opinion, Boric Acid is the best roach killer because it works. period.

Harris – My Favorite Brand

Roach Killer Powder, 16 ozHarris Roach Killer Powder is my favorite brand because it’s cheap and seems to work faster than other brands. When I use it, my roach problems go away – which is all I really care about. The tablets also come in handy.

The reason I use Harris, is because I’ve found that other brands sometimes dilute the product with filler, making it not as potent and less effective.

One easy trick is to mix the powder with sweetened condensed milk until it becomes a sticky paste.  The paste is an edible poison that the roaches cannot resist.

When my tenants complain about roaches, as a measure of good faith, I usually buy some Harris Brand Boric Acid (which comes in tablet and powder form), and spend 10 minutes putting it all around the house – anywhere that I think roaches might be hiding.  The powder comes in handy for laying a line of poison or squeezing it into holes and hard-to-reach places.

If there are too many roaches already, and an infestation is already well underway, I just simply call an exterminator and make my tenants pay for it (per the lease of course).  Boric Acid usually works in 1-5 days, but if the problem is an urgent one, exterminators will treat the property with high-powered chemicals and “bombs”.  Just be mindful of your tenants and pets before going nuclear.

Learn More

Guide to Roaches

Read my other in-depth guide that describes How to Kill Roaches in a Rental Property

  • Other roach-killing products
  • How to know when to call an exterminator
  • Useful lease clauses that address roaches and infestations
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66 CommentsLeave a Comment

  • Jim Davis

    I have spent a great deal of time in property management. We tried everything until we finally found a boric acid paste professionally made by landlords. The paste had been around for many years and yet we hadn’t heard of it. It is called MRF 2000 and it is the best thing we have ever used. Instead of spraying all the time, we can now treat an entire complex with one application and get an entire apartment building roach-free; what a relief.

    • Lucas Hall

      Hi Jim,
      Thanks for your feedback. The MRF 2000 seems similar to the paste I describe. But the fact that it already comes pre-packaged, and I don’t have to mix it is very nice!

      • Duane

        I need to know we’re I can get boric acid so I can get ride of a roach problem

      • Duane

        I need to know we’re I can get boric acid so I can get ride of a roach problem could u use Condensed milk mixed with boric acid to turn it into a liquidation so you can spray it all over instead of paste

        • Andrea speer

          Hi u can order it from amazon . it is expensive. I got mine from dollar general for two dollars and fifteen cents
          Good luck

        • Michael

          You can basically buy this product anywhere, hardware stores, Wal-Mart, Home Depot, etc….you can also order it online at Amazon.com

    • Julie Taylor

      How do you make this paste and how much of what??? Please help I’ve tried everything. Right down to a year contract with a national pest company…

  • joe

    unfortunately for me, I live in california, and I am legally not allowed to charge the tenants for bringing an exterminator. It is my responsibility. Damn..

    • Lucas Hall

      Hey Joe,
      It’s great to meet you. Thanks for your comment, but it’s not entirely true.

      Here’s my understanding of CA laws:
      1. The landlord must provide a clean, pest-free home when the tenant first moves in.
      2. At any time during the lease, a landlord must take action to get rid of any pests that show up.
      3. However, the burden of paying for the pest removal falls on the person responsible for pests in the place. If your tenant’s living behavior causes a mouse and roach infestation, then you still have to take action to rid the house of them, but you can charge it back to the tenant.

      I’ve never seen a law that requires the landlord to pay for pest treatment under all circumstances. What if you have a hoarder tenant? Please prove me wrong if you can cite the statute.

      • Karl

        The landlord should ALWAYS be responsible for the cost of exterminators/pest control unless the tenant is responsible for bringing them into the property. If I ever had a landlord that demanded that I pay for pest control when it was not my fault, I would move out of there fast. Especially in an apartment. Think about it, you could be the cleanest person on Earth, and your neighbor is a junklord. Now, you have a bug problem because your neighbor is causing an infestation. Why should I have to pay for that?

        Again, I totally agree if I am the one causing the problem, I should pay, but if not…why?? I don’t understand your stance on this.

        • Lucas Hall

          Hi Karl

          We’re saying the same thing. If the tenant is the cause of the roach infestation, they should pay to remove them. If the tenant is not the cause, then the landlord should pay for the extermination.

  • yudi

    I live in indonesia it is hard to find it so you can advise me how i get it ?

    • Lucas Hall

      Hi Yudi,

      I wish I could help, but I wouldn’t know how to get Boric Acid in Indonesia. Would Amazon ship there, or is that wishful thinking?

    • arjen

      im currently in guatemala. Here it is sold at pharmacies in tiny bags that cost 0.13 USD

      • arjen

        I believe they use it against infections or something. So maybe pharmacies in other places have it too :)

        • Matt

          I found some Boric Acid at the walmart drugstore here in Toronto / Canada.
          You have to ask for it (over the counter) but you don’t need a prescription. It is used diluted in water topically to treat minor cuts and burns. I mixed it up with a bit of flour and syrup to make a paste I put all over the place behind the stove, fridge, freezer, couch in the cupboards etc etc where ever they may hide!

  • Marilyn

    We are battling a roach infestation at my elderly Mother’s home. She continually calls the exterminator out, they spray but it never gets rid of them. It is a “never ending story”. I feel like they are taking advantage of her. I’ve also read that exterminators have changed the chemicals in their product because if they kill the roaches, they do not get called back, therefore business is not good. Do you have any special instructions to go by if we decide to try this in her home?


    • Lucas Hall

      Hi Marilyn,

      I would use the powder boric acid and squeeze (spray) it into every nook and cranny. Then make a paste out of it, and put it on the insides of your cabinets wherever you are seeing roaches.

      I give some more details here; http://www.landlordology.com/how-to-kill-roaches/

      If that doesn’t work, you may have to “bomb” the house, which would involve your mother moving out for a few days.

      Also, you could try a different pest removal company. Some are better than others. Try searching Angie’s list for a A+ ranked company that has lots of experience with roaches.

  • gabriel smit

    your 100% on target with boric acid. with diatomaceous earth, it will kill most household critters like cockroaches, fish moths, crickets, fleas, ticks and bed bugs.
    it is cheap, less toxic than table salt and works like a bomb!

  • EJ

    Just moved in to my sisters house roach free. I used to live in an apt Complex with roach problems. I took forever to move out cuz I wanted to make sure that the stuff I took into her houdr were roach free I saw four roaches already. What sgould I do? My sis is freaking out cuz she hates roaches.

    • Lucas Hall

      Hi EJ,

      Roaches are super sneaky, and it doesn’t surprise me that they found a place to hide during the move.

      Anyway, check out my other How-to guide about roaches. I think you can definitely take are of it yourself with the right poison/tools. Otherwise, any of the major pest control companies would happily get rid of them for you.


  • April Fairfax

    Want email

  • Gabriela

    Hi, I’ve been living in my home since last August. When the temperature changed and got warmer, we started noticing roaches. I have children. If I started the boric acid process how long would it be until it’d be safe for my family to come back home?

    • Lucas Hall

      Hi Gabriela,

      I’m not boric acid scientist, but the trick is to squirt the powder into the nooks and crevasses in your home – far away from the kids and pets. If you use the tablets, just put them where you are seeing roaches, and make sure your kids can’t get to them (the same as you would treat mouse traps).

      In this guide, there’s a video to show you how to make a paste that will stick to cabinets.

      As long as the powder or tablets are out of reach, it should be safe for you to live there during treatment.

  • Becca


    I am a tenant renting in Chicago. Recently I found roaches in my apartment. I was shocked because I am an extremely clean person. The tenants living downstairs moved recently, and I believe they are coming from there. I contacted my landlord but they said it is my responsibilitie after 30 days of moving in. How can I treat this problem if it isn’t just a problem in my apartment?

    • Lucas Hall

      Hi Becca,

      If I were in your shoes, I would politely approach the neighbor and say “Hi there, I’m Becca and I live above you. I noticed some roaches in my apartment, and I was going to hire a pest company to exterminate them. Since we share walls, they are probably in your unit too, and I was wondering if you wanted to split the cost of extermination for both of our units. It would be cheaper if we go-in together.”

      Other than that, you’d have to prove that the roaches are being caused by dirtiness or neglect from your neighbor, and then seek damages from them. You could also talk to a lawyer, about how best to deal with your neighbor. Further, you could also try some of the remedies in this guide: http://www.landlordology.com/how-to-kill-roaches/, which would be much cheaper than an exterminator.

      I hope that helps some. I’m sorry you’re having to deal with roaches.

      • Anthony

        I have a simple question. I hope … so will the borax acid work mixed with peanut butter? I live in my sister house and when she lived here she had an exterminator on a contract. So we had no bugs..well my sister moved out and I got a roommate and they definitely brought them with them. So when they moved out almost 1 month ago they took the fridge and stove washer and dryer Ect. When they moved I had a guy come spray and they seemed to be getting better.. he told me to be glad they took the fridge and stuff bc they took hundreds with them… well in my room they had gotten pretty bad so he sprayed very little in my room but used this paste stuff that looked like peanut butter in a tube . Will it work mixed with peanut butter?

        • Lucas Hall

          Hi Anthony,

          That’s an interesting idea. I’m not sure. I know you can mix it with water, but I have no idea about peanut butter.

          The “peanut butter in a tube” is a professional bait. The roaches eat it and and it makes them sterile. It does not have any peanut butter in it.

  • Emma

    Hi there,
    This sounds like an awesome product and I want to try it out but I’m pregnant and worried about the chemicals. I would of course not be handling the product but is it safe to have in my house? In which form is safest? I’m thinking the paste you say is efficient might be better then a powder that can be airborne? Any thoughts and tips are appreciated. Thanks!

    • Lucas Hall

      Hi Emma,

      As with any chemical, try to use it in places that won’t come in contact with babies, elderly, or animals.

      The powder form will get into the area (just around where you spray), but the paste will stick to things and not be airborne. The powder though provides more coverage and you can blow it into cracks (where they hide).

      Just buy a bottle and give it a try. You’ll figure out what works for you.

  • Abel

    I just got the boric acid, I guess I was expecting next day results, but maybe previously using a diff spray they been hiding and now came out with a vengeance, I just laid the acid 3 days ago how long before we see results, and also what are the ways to make paste. Thank You

    • Lucas Hall

      Hi Abel

      If they are interacting with the boric acid, I’ve usually seen a noticeable difference within 3-5 days. If you don’t see any difference, apply the spray in more places and use in collaboration with other off-the-shelf roach poisons. Read the other article: http://www.landlordology.com/how-to-kill-roaches/

      There’s a video that shows you how to make the paste.

    • Stephanie

      I saw immediate change. I would enter my kitchen like it was a gladiator ring! I placed the acid 2 nights ago an awoke to roach roaming. The next morning, same thing. I am going out of town in a month and I plan to bomb as well. Roaches are such a nuisance.

  • Cathy

    Hi there,
    I had some squatters living next door. Our homes are not connected. These people were NASTY!!! They finally got kicked out but we started seeing roaches when they were living there. Initially on our fence & the side of our house in record numbers. We have called an exterminator who has treated the house twice. We are slated to call them again because after putting down a lot of boric acid in the kitchen which is where we see them a lot, they have not taken residence in my bedroom!!!!! I’m not sleeping to say the least. I’m afraid they are going into my toddler’s room next. Please help me!!! I want those bastards gone. By the way, the house next door is not vacant & red tagged. I’m assuming they are going to continue to come over the gate & into my house. Please please help!!!! Thank you!!

    • Lucas Hall

      Hi Cathy,

      When the roaches are that many, you’ll continue to need to work with an exterminator. Further, I suggest using the powder boric acid and laying a barrier on that side of your house. Also, open up all your outlet covers and seal any gaps with spray foam, and boric acid. If you can seal up your house, the roaches will have a hard time getting in.

      Many pest control companies also have a year long subscription, with a guarantee. The guarantee will cost you upwards of $400, but it’s better than roaches! Plus, you might be able to convince the owner of the next door property, to reimburse you.

      Good luck!

      • Cathy

        Thank you for your comment. I actually meant to write the house next door is vacant & red tagged. Squatters were thrown out!!!!! Thank you God!!! The house is in fourclosure. I’m sure it’s still infested. But I’m hoping the roaches stay there now that it’s getting cooler out but I’ve seen some bold ones crawling in at the top of my side door. I do have a contract with the exterminator & do the above. I just feel like we are never going to be free. The storm drain is also in front of my house right off the curb. Could that also be causing a problem?

        • Lucas Hall

          Hi Cathy,

          Hopefully the storm drain doesn’t have any breaks or cracks that might allow them into the house. Otherwise, if it’s sealed, they are not likely to come through the plumbing traps which are sealed with water.

          That’s just my understanding. I’m not a pest professional. It would be worthing asking the exterminator next time.

    • Karl

      Geez, calm down! It’s just roaches, lol. They are a pain, but it’s not the end of the world.

  • Lora Sledge

    Hi, I’ve been living in my downstairs apartment since July 2014. I have sprayed, put down roach traps, and gel my apartment, still no help! My neighbor above me is filthy anfd tne roaches are coming from up there, I have bought some Harris Boric Acid Powder. I need to know what to do because the roches are coming from my ceiling and the top of the walls!

    Please help!

  • Stephanie

    Hi Lucas,

    Thank you so much for the great tips. I currently rent an apartment with my 3 1/2 year old son. We are moving from our current location to another location within the same complex. There was an infestation that was so bad that they evicted the people in the unit that was the source of the problem (which happened to be right below our unit) the day of the inspection.

    The leasing office told me (unwillingly) that there are a couple of units in the new building. We get the new unit keys Nov 7th and have until Nov 9th to move out of our current unit. I’m not OCD, however when it comes to bugs I am now. If I spread the powder along all the baseboards as soon as I get the keys (Friday) will it be safe to have my son’s toys moved over by Sunday?

    Thank you so much for any suggestions you may have.

    • Lucas Hall

      Hi Stephanie,

      I don’t recommend putting boric acid on any surface that a baby could touch. I’m not an exterminator, but I think it works best when squeezing the powder into the cracks or areas where the roaches are entering the unit. If there are cracks under the baseboards, you can squeeze it into there.

      Or, check out my other How-to guide for making a paste out of boric acid:

      If you have any other concerns about the product, you should contact the manufacturer: http://pfharris.com/

  • Janacarles

    where Can I get this Harris boric acid or tablets… Thank you

    • Lucas Hall

      Hi Janacarles,

      Just click on any of the links in the article above and it will take you to the Amazon page where you can buy it. You can also find it at most hardware stores, or even many grocery stores.

  • Beatbox

    We had a roach problem in our kitchen in our NYC apartment. I picked this up at the local hardware store. I recommend getting serious about applying it. emptied every cabinet of food and dishes and put a thin line of this in every seam in side the cabinets and along the counters, Along every baseboard, behind and under every appliance until there was no way to get in without crossing the stuff. (Note, I used a damp sponge to pick up any extra along the counters and in the cabinets so the only stuff was actually in the seams.

    Now, this was a 4×6 NYC kitchen, so this took all of 20 minutes.

    Bottom line, we went from wanting to move to NEVER seeing another single roach.

    • Lucas Hall

      Hey Beatbox!

      That’s awesome! Thanks for sharing.

      I just applied this stuff at a rental property that had a big roach problem. It’s been a week and I’ve not heard a peep out of the tenants. I too applied a very liberal amount on all the seams in the cabinet.


  • jennifer prats

    My daughter moved to a new apartment 11 days ago we have tried everything to get ride of small black and German roaches. She has had pest control and we have used glue traps, raid spray and bait in a tube. Nothing is working. I am going to see if I can find the powder today thanks.

    • Lucas Hall

      Hi Jennifer

      Good luck! Be sure to buy the bottle with the tipped nose. That way, you can squeeze/spray it into all the cracks. Remember to use a liberal amount.

  • Kat

    You can buy boric acid at Dollar General. It works wonders! We live on a cattle farm and always have bugs coming into our house. We spent years and tons of money probably in the thousands..paying someone to come out to our house and spray. We used every single major company to no avail. We’d had enough.. Then someone told me about boric acid. I though.. its worth a try. I pulled everything out of my cabinets and dusted. I moved all of my appliances and dusted under them. I went around all of my baseboards in all of my rooms with it. I never made a paste. I didn’t wash it or clean it up. I just left it be (no mopping close to the baseboards) I always washed my dishes when I used them because of the dust but hey.. I was doing that anyways because of the roaches. Less then a week later I was completely roach free! I fired my pest control company. It’s been a year now and I still don’t have any bugs. Also at this time I had a 1 year old a few cats and dogs. It’s pretty safe stuff.

  • marie

    We had out home built last year. Our neighbor next door move out a few weeks ago. We when the lardlord their went to clean up that when their roaches stared coming on my porch. Sometimes I see one in the house like each other day. This been going on now for almost 2 werks

  • Donna Dale

    I have been into a new home for 3 weeks, it was infested with roaches and the landlord had the extermintaor come out and he has been back twice. Once he gets rids of all the bugs and I take control……Can you put the boric acid in the seams of the cupboards where you keep dishes? I am not worried about canned goods as I wash them always due to rats and no telling what else contaminates them during storage packing etc. If I use it in the dish cupboard, should I wash each plate before using to be sure nothing is on them? It is disgusting. I keep everything I am using right now, in the refrigerator and will not unpack until I see no signs. Is this over kill on my part? I hate roaches and never dealt with them before. Thanks

    • Lucas Hall

      Hi Donna, if you want to treat the cabinets where your dishes are I suggest using a gel product and placing it along the hinges of the cabinet doors along the seams as not to infect your dishes. Boric acid is a powder and therefore easily disturbed. I suggest you take precautions as not to ingest the boric acid powder.

  • Amanda

    I recently started using this at our property and I have found it to be the cheapest, easiest and best way to combat a roach issue!

  • Tricia

    My old apartment building was continuously infested with just about everything – had to move FAST and they had space. They paid for exterminators (not sure if it was because it was section 8 allowed, or because of how their lease was drawn out – it was a very strange and draconian lease that “surrendered some of your legal rights” so likely that.) Now we’re in a new place that is spotless and perfect aaaannd.. I think someone just moved out upstairs.. I don’t *recognize* these little guys, and I have only seen three nymphs so far. They are quite terminally stupid for roaches – they’re out during the day, they’re not bothering with cabinets, and they seem to just be trying to get to the water. I blanked on the Borax trick, thanks!

  • Patrice

    Hola, My husband and I just bought a house in Mexico and are finding that when the neighbors spray their super disgusting toxic chemicals that we get the escapees. Now we are from Canada and have not dealt with these critters before now, we brought our 88 lb. dog with us who loves to hunt and kill them. The house is old and we are doing repairs on it as we live in it. What do you think is the best plan of attack for us? I bought some acido borico yesterday and some icing sugar and the Internet is full of ideas but I’m really out of my league here. Any and all advice will be greatly appreciated. Thanks

  • Altie

    We have been having an issue with palmettos and germans but they aren’t in or around the food they are in our dishes cabinets and dining area. We just got done caulking all the cabinetry tonight, I wanted to know if you think they’ll still take the bait if they don’t go after our other food? And does boric acid work on Palmetto bugs? Really want to solve the issue quickly with as few chemicals as possible as I have a baby who’s just about crawling. Thank you.

  • Lori White

    Mixing Boric Acid with equal parts powdered sugar and putting it near a water source is also an effective solution.

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