Why Does Salt Kill Slugs?

Holes in leaves, vegetables disappearing and pots covered in slime. It can only be one thing: Slugs! One common way of getting rid of slugs is to sprinkle them with salt. But why does salt kill slugs? What does salt do to them?

Salt kills slugs through a process called osmosis. The salt enters the slug’s skin which is permeable and draws water out. As a result, the slug becomes dehydrated and dies a short while later.

Slugs need a high water content to survive, and by sprinkling salt on them, they become instantly dehydrated. 

Do Slugs Scream When You Put Salt on Them?

As you sprinkle them with salt, slugs will squirm and move around, but they do not scream when you put salt on them. It’s rare for a slug to make any audible noise.

Slugs do not feel pain the same way humans do. This doesn’t mean they feel no pain though. Slugs do feel a high level of discomfort, hence, the squirming.

Many people consider it cruel to put salt on slugs. As slugs rely on water, you are depriving them of it by pouring salt on them. There are better and more humane ways to deal with slugs rather than pouring salt on them.

By sprinkling salt on slugs, you will effectively be suffocating them which, in no way, can be described as a pleasant experience.

In addition, if you avoid using salt, it is better for you and your garden. By using salt, you may kill some slugs but at the risk of damaging your plants. The salt that inevitably ends up in your soil can change the balance of nutrients which can hinder the growth of some plants.

Do Slugs Die Instantly from Salt?

If you want instant results, you can pour salt on slugs. By putting salt on slugs, you can kill it in seconds. However, for the salt to be effective, you need to almost bury the slug in salt. A little salt will not do the job, as you need a lot of it for osmosis to take place. 

If you have a large slug infestation, using salt to tackle it may not be a wise idea. It would help if you had a lot of salt, but remember it can cause damage to your soil.

The salt can increase the salinity level in the soil, rendering it useless for years if you use this method often. 

In addition to soil, the salt will also cause damage to other surfaces like paving, painted walls and floors, and anything wooden. Where possible, consider one of the many other natural slug repellents (we’ve listed plenty here).

Does Salt Deter Slugs?

Many people assume that salt can be used to deter slugs. However, this is not always the case. Salt is used mainly to kill slugs, but it is only effective in the short term.

Firstly, you require a lot of salt to kill one slug, and if you have a large infestation, using salt will not solve the problem. You need to use salt directly on each individual slug so sprinkling 10, 20 or 30 slugs with salt is not an efficient way to deal with them.

A way you can, however, use salt to deter slugs is to create a barrier. You can have the salt barrier around the base of plants that are particularly impacted by slugs. Simply sprinkle a solid line of salt around the base of the plant.

Unfortunately, this is also not the most effective deterrent against slugs as a little wind or rain will wash the barrier away and you’ll have to repeat the process over and over again.


One of the ways people tend to tackle their slug problem is by using salt. Salt works by entering the slug’s skin, which is permeable, drying it out from the inside. The process is called osmosis and dehydrates the slug.

Slugs rely on water to stay alive, and putting salt on them can kill them in seconds. It can be uncomfortable, however, which is why you’ll often see a slug squirming when salt is placed on them.

For the salt to be effective, you need to use a lot of it. Using salt to kill slugs can have adverse effects on your garden and plants. The salt increases salinity in the soil, rendering it useless.

Instead, we would recommend exploring other methods of controlling the slug population such as using beer traps, growing plants they hate and encouraging natural predators to your garden.

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