It can be hard to keep roach populations down in old homes and apartment buildings without also adding a heavy dose of toxic chemicals to the rooms you live and eat in. In an effort to kill pests and not our health, natural pesticide options are always in demand. Usually, the simplest common household ingredients can be repurposed as lethal pesticides.
When it comes to cockroaches, the chemicals to kill them are harsh, so the natural remedies have to be pretty intense to be effective. There are several ways to naturally repel and kill small populations of roaches that surface around our homes, but to fully eradicate them often requires a much more complex approach with the help of professional pest control services.
So then, can something as simple as salt kill roaches? Let’s find out!
Can Table Salt Kill Cockroaches?
No, in most cases tossing table salt around the house will not kill cockroaches. If you are able to completely bury a roach in salt or spray dissolved salt directly on them, then you may be able to kill roaches with salt. The process would be more complicated than warrants, and more effective powders exist to fight roaches.
When trying to get rid of roaches, a pinch of salt cannot puncture or dehydrate cockroaches from the outside. Common table salt is not a natural pesticide like diatomaceous earth or boric acid salts but can often be mistaken as one. DE is very sharp and will slice the exoskeleton of most insects leading to dehydration and eventual death, whereas borax, baking soda, and ammonium nitrate can all lead to the systemic erosion of internal systems.
Will Salt Repel Roaches?
Salt should not be looked at as a reliable roach killer. While some salts may have chemical components in them that could prove lethal to roaches, it is not really a substitute for a comprehensive pest control program. However, outside of the home, where cheap methods of pest deterrents are valuable at scale, salt can be used as a roach repellent.
Liquid salt can be sprayed on package materials in the food industry to keep roaches and pests from crawling on and trying to get inside large bags of food. A spray bottle at home could do the same if you wanted to create a barrier along the pantry or food areas. American cockroaches and German cockroaches are likely to avoid salt more than other types that don’t seem to have as much experience with it.
The texture and scent of common salt don’t have any repellent effects on roaches if just a pinch of salt is laid down, but a mound of salt is not as easily crossed and can delay roaches from entering an area for a short time. As a last-ditch approach, you can also dissolve the salt and essential oils together and spray it to reduce evaporation and provide a stick substance that is likely to attach to roach legs.
Types of Salts
While common table salt won’t kill roaches, salts come in many forms. There are several types of salt that have repellent and toxic effects on roaches and, if used correctly, can temporarily stop roach infestations from spreading. Bath salts and other non-culinary powders can be included to help with your roach problem while figuring out a long-term solution
| Salt Type | Common Use | Effect on Roaches |
| Table Salt | Cooking | No Effect |
| Epsom (Magnesium) Salt | Bathing | Toxic |
| Alum (Potassium) Salt | Wood Finish | Toxic |
| Garlic Salt | Cooking | Repels Roaches |
Table Salt (NaCl)
This is the salt you add to your food to make it taste like something. While it’s nice to think that just sprinkling some of this salt around your kitchen at night can stop roach invasions, it’s not that simple. While putting salt on the floor can deter some insects, it really won’t stop cockroaches from looking for food products. Cinnamon, vinegar, or borax are better insecticides, dusts, and sprays to stop the occasional cockroach infestation.
Epsom Salt (MgSO⁴)
Much more powerful than ordinary table salt, bath salts are an effective roach killer that can reliably save a house from roaches. Just like with borax and boric acid sprays, apply to the bathroom floor and floor tiles to treat with an Epsom salt pest control mixture. It will take a lot of salt to battle roaches, but it is a safe control method and is better than trying to use iodized table salt.
Alum Salt (KAl(SO₄)₂·12H₂O)
This is mainly used in wood finish and is not likely to be in your household pantry. If you do woodworking or are a carpenter, then you may have some of this lying around, and in that case, it can be used to repel roaches. Like bath salt products and borax, alum salt acts as an insecticide when it is ingested by American cockroaches, German cockroaches, and brown-banded roaches. Liquid salt treatment is the best way to use this slightly green crystalline salt.
Garlic Salt (C¹²H²¹NO⁴S³)
Flavored salts can add an extra boost to dry powder table salt’s ability to repel pests. While ordinary salt may not do much, salt that has been combined with plant-based ingredients that have strong odors, like garlic, is much more potent and effective at repelling roaches. You will need lots of salt for this to be effective, but if you find yourself like seasonings to spare, go ahead and try to stop cockroaches this way as well.
How to Kill Cockroaches with Toxic Salts
Even though it will take a mountain of salt to kill a house full of roaches, some toxic salts can be used to keep them at bay. A roach infestation can get bad fast, and any solutions on hand are better than imagining all of them crawling around all night with nothing to stop them. To make the most out of covering the house with salt, follow the tips below.
Location
As much as we want to cleanse a house after the first sight of a roach, it can be tricky to cover every floor in every room. to make the most out of limited roach-killing and repelling products, you will need to be strategic with where you place it. It helps to start placing the powder salt or spraying the dissolved spots in rooms and areas of the floor where you have seen the roaches. The other place to lay salt is near where food sources or water is present and where you expect pests to go.
Powder Form
Lay a thick layer of powdered salt to make sure you coat the legs of all passing roaches. Cockroaches prim themselves and clean with their mouths so anything they pick up will be ingested. Covering a wide area and leaving it for up to a week can make sure roaches have some exposure to the chemicals.
Liquid Form
If you dissolve salts in liquid and spray in cockroach-infested areas, then the roaches cannot move without being covered in the sticky salts. If you use borax or bath salts, then any salt the roaches eat will have a negative effect on their digestion. Enough grains of salt dissolved and eaten can kill roaches and keep infestations out of common living spaces.
Application Rate
Since salt for pest control is a household measure, it is hard to find an exact application rate. Instead, it is easier to visualize what you are trying to accomplish and apply it to that goal. If there is an area of the house you want to keep roaches out of, then piling mounds of salt or spraying these areas heavily may discourage roaches from entering. If you want to destroy certain bugs that keep coming inside, then placing the toxic salt where they will be is a better solution.
If you can leave the salt and reapply whenever it gets old or brushed away, you should start to see a marketed decline in cockroach activity. You may not be able to kill all the roaches with toxic salts, but you can help keep them away from your kitchen and bathroom areas. Combine salt treatments with other methods to get rid of roaches for good.
