It's natural and practically free - keep your backyard looking its best with this simple ingredient you already own

Salt can be an effective weed-killer as long as you know how to use it. These simple expert instructions will help you keep your backyard looking its best

garden lawn in backyard by Joseph Richardson of Richardson & Associates Landscape Architecture
(Image credit: Joseph Richardson of Richardson & Associates Landscape Architecture)

It's delicious sprinkled over your eggs in the morning, but you may not have known that salt isn't just a household hero - it's also an efficient way to kill weeds naturally.

Learning how to kill weeds with salt means you can eradicate your patio from the unwanted invaders without using herbicides.

'While herbicides can effectively target and destroy weeds, many commercially available products can also be overly toxic to neighboring plants and wildlife,' says Andrew Gaumond, editorial director and horticulturist at Petal Republic. 'Salt is a naturally occurring mineral that can effectively kill unwanted weeds.'

However, you do need to proceed with caution, as you'll find out in our guide on how  to kill weeds with salt below.

How to kill weeds with salt

backyard patio seating by Joseph Richardson of Richardson & Associates Landscape Architecture

(Image credit: Joseph Richardson of Richardson & Associates Landscape Architecture)

Our expert Andrew Gaumond reveals why run-of-the-mill household salt is an effective weed killer, and how best to go about using it to rid your garden of them.

1. Prepare a salt solution

You will need to start by preparing your own salt solution to spray onto the offending weeds.

Andrew says: 'To prepare your own salt solution at home, I'd recommend starting with 1 part salt to 5 parts warm water dissolved in a spray bottle. 

'Ensure the mixture is thoroughly dissolved before applying it to your weeds.'

2. Spray the weeds

Once you have your salt solution, you're ready to administer it.

'Spray the salt solution onto the foliage and base of the weed(s) you want to eliminate,' says Andrew.

'It's prudent to work through 2 or 3 light dosages over the course of 7 to 10 days and closely observe the impact on the weeds. If you're not seeing much progress by day 10, increase the dosage from 1 part salt to 3 or 4 parts water.

'For an added boost, you can add in 3 or 4 teaspoons of vinegar, which contains acetic acid, a further accelerant to dehydrate plant tissue.'

bakyard patio dining and seating area by Joseph Richardson of Richardson & Associates Landscape Architecture

(Image credit: Joseph Richardson of Richardson & Associates Landscape Architecture)

How does salt work to kill weeds?

Salt (which is primarily composed of sodium chloride) kills weeds by disrupting the osmotic balance in the plant cells through dehydration that causes the weed to wilt and die. 

However, warns Andrew, the sodium ions present are also toxic to other plants, and you don't want to be ruining those beautiful flower beds you've spent so long tending (more on this later). 

What type of salt can you use to kill weeds?

The best types of salt to consider for weed-killing purposes are everyday table salt or rock salt (both have similar mineral properties, with rock salt being a little coarser).

Can using salt to kill weeds be harmful to other plants?

Yes, using salt to kills weeds can be harmful to other plants that may be growing nearby.

Salt can be absorbed through root systems of adjacent plants, making it difficult for them to absorb water. It can also lead to a loss of biodiversity.

'It's essential to be aware that overdosing your garden with salt can lead to problems for other plant life as the soil's pH balance will be thrown out of sync, taking several seasons to rebalance naturally,' warns Andrew.

'Salt can also be harmful to pollinators and beneficial insects in your garden, which can lead to a loss of biodiversity. 

'Salt-based herbicides are also non-selective, so there will always be the potential to damage other adjacent plant life.'

If you're going to use salt to kill weeds, it's best to stick to using it around patios, graveled paths, or pavers, away from other plant life.

Andrew adds: 'I'd recommend seeking other, less impactful, herbicidal solutions for thriving garden and flower beds or vegetable gardens.'

The salt spray starter kit

Ruth Doherty is a lifestyle journalist based in London. An experienced freelance digital writer and editor, she is known for covering everything from travel and interiors to fashion and beauty. She regularly contributes to Livingetc, Ideal Home and Homes & Gardens, as well as titles like Prima and Red. Outside of work, her biggest loves are endless cups of tea, almond croissants, shopping for clothes she doesn’t need, and booking holidays she does.