Does salt kill weeds? Absolutely, but gardening experts urge you to take note of these key considerations first

 Weeds in between patio slabs.
Weeds in between patio slabs.

Weeds have been a hot topic lately, so naturally we've been on the hunt for the best ways to get rid of weeds in the garden. While there's always the option of using dedicated weedicide for the job, if there's a hidden gem in our kitchen cupboards that'll do the trick, we're all ears. This has led us to wonder whether salt kills weeds.

In case you don't know, we're currently on a bit of a journey at Ideal Home to find the most effective ways to kill weeds. From using white vinegar to clueing ourselves up on the reasons why we shouldn't use bleach to kill weeds, we're learning more every day to finally tackle the job of successfully removing these unwanted plants surrounding outdoor spaces.

In an ideal world, being able to use something as accessible as salt to get rid of weeds is the best-case scenario. You've always got it on hand in your kitchen cabinets, and it's affordable enough to buy in bulk. Thankfully, gardening experts have revealed that salt is an effective method but, as with anything, it comes with a couple of caveats...

Weeds in between patio slabs
Weeds in between patio slabs

Does salt kill weeds?

Yes, salt does kill weeds. Jane Dobbs, team lead of gardening at Allan's Gardeners explains that salt kills weeds by drawing moisture from them and disrupting their water balance. 'Salt, particularly sodium chloride, is a cost-effective and natural weed killer. As salt is applied to soil, it pulls moisture out of plant cells, causing dehydration and eventually plant death.'

'The salt method also prevents further growth of weeds,' adds Harry Bodell, garden expert at PriceYourJob. 'There are certain ions present in salt which can be toxic to plants when accumulated in high concentrations, interferes with natural processes such as photosynthesis, leading to cell damage and dehydration of the plant.'

However, although salt is an effective weed killer, it still comes with downsides and key things to consider before you use it in your garden.

Weeds in between patio slabs
Weeds in between patio slabs

'Salt still has a few risks and it has some environmental consequences,' explains Jane. 'Salt accumulation in the soil can disrupt soil structure, stunt plant growth, and impact the environment.'

'Leaching salt into groundwater or nearby water bodies can also harm beneficial salt microorganisms. In the long run, salt can lead to barren spots that don't grow most plants, which is counterproductive for gardening.'

It's not all doom and gloom though. Although there are some issues that salt can cause to the soil and surrounding plants and flower beds, so long as you're using it in small, diluted quantities, you won't find yourself with a garden nightmare.

Weeds in between patio slabs
Weeds in between patio slabs

How to effectively use salt to kill weeds

'It's best to make a very weak salt and water solution for a start and only use it at spots where soil health won't be an issue in the future,' advises Petar Ivanov, gardening and plant expert at Fantastic Gardeners.

'I'd suggest mixing 3 parts water and 1 part salt for the solution and applying it to the very base of the weed using a funnel and being very careful. After that, you can increase the amount of salt in the solution a little bit every day until you start seeing the weed is being affected.'

If you choose to try out this method, Jane says that any nearby plants need to be watered after you apply the solution. 'It will prevent damage and allow the salt to leach below the roots.'

Flexible black plastic funnel
Flexible black plastic funnel

Draper 56141 Flexible Plastic Funnel

The flexibility of this funnel makes it perfect for reaching awkward spots and ensuring the salt water solution only reaches the targeted areas.

For areas with concrete, Petar assures you can use this salt water solution a lot more freely as there's no risk of causing harm to other desirable plants. This includes getting rid of weeds in gravel and stopping weeds from growing in block paving.

'It's important to do this on a particularly dry day so humidity and rain don't wash away the solution,' adds Harry. 'Overnight, the solution will work on drying out the plant to the root, making the weed easy to remove the next day.'


Does salt kill weeds permanently?

Salt can kill weeds naturally, but it won't solve any larger weed problem permanently. In the case you're dealing with a lot of weeds, you'll likely need to opt for a more comprehensive weed control strategy, recommended and carried out by professionals.

How long does it take for salt to kill weeds?

'It'll take up to 10 days for the weed to properly absorb the salt in the water and it mostly only works on smaller and young weeds,' explains Petar Ivanov at Fantastic Gardeners.

'Besides that, you won't be able to plant anything in the spot which you've treated with salt because sodium chloride doesn't break down and it'll take up to several years to be entirely washed away.'

So, the verdict? Salt is definitely an effective way to kill weeds naturally, but should only be used sparingly and carefully, keeping the above important tips in mind.