Does baking soda kill weeds? Yes, but experts urge you to think twice before using this cupboard essential in your garden

Baking soda can kill weeds… but it’s not the only thing it can kill

A flower bed by a garden fence
(Image credit: Future PLC/Colin Poole)

You probably don’t need us to tell you that baking soda is the ultimate store cupboard essential. But does baking soda also kill weeds? Well, we’ve got some good news and some bad news.

Weeds are the bane of every gardener’s existence and can ruin even the best garden idea. While there are so many ways to kill weeds, it’s fair to say that more and more people are trying to steer clear of chemical-filled weed killers and are opting for natural alternatives. In fact, that’s why so many people are turning to salt to kill weeds and white vinegar to kill weeds.

However, it seems as though there’s another natural weed killer on the block, too. But while baking soda can indeed kill weeds, experts urge gardeners to be cautious when using this popular cleaning product in the great outdoors.

Does baking soda kill weeds?

While you may have already mastered the baking soda sofa cleaning hack, what you might not realise is that this product is pretty universal. In addition to helping you clean inside your home, it can also help you tidy up the outside of your home - especially if you’re looking to get rid of pesky weeds.

That’s because baking soda - AKA sodium bicarbonate - is essentially a salty alkaline powder that dehydrates and kills weeds in their tracks. In fact, Ted Bromley-Hall of UK landscaping materials manufacturer IBRAN, explains, ‘For the weed, it's death by thirst!’

He adds, ‘Baking soda is composed of sodium and bicarbonate and is slightly alkaline, which makes it good at desiccating plants, drying them up so quickly and effectively that it's impossible for them to drink any more water.’

baking soda in storage jar

(Image credit: Garden Trading)

When this happens, it shouldn’t take long for the foliage to die. Then, you should be able to pull up the weeds (including the roots) and prevent them from returning. There’s an art to successfully killing weeds with baking soda, though.

Ted says, ‘You'll need around a tablespoon per litre of water as a baseline, whilst larger, more established weeds will need stronger concentrations to shift. It's also best to apply the solution to the plant on sunny days, as rain will dilute or wash away the soda.’

And while you may be inclined to simply fill a spray bottle with water and baking soda, Ted urges you to consider a different option.

‘You can put the solution into a spray bottle, but it will result in the bottle "furring up",’ he explains. ‘Plus, it's harder to control the application as the spray nozzle could end up spraying it onto plants you want to keep. The most direct way to apply the solution is to paint it onto the weeds.’

‘As the sun evaporates the water from the bicarb solution, it leaves behind a baking soda "film" around the outside, which pulls water out through the pores in the leaves, which in turn pulls moisture up through the stem, drying out the whole plant.’

But while using baking soda is a nifty hack, it’s important to understand that killing weeds with baking soda isn’t always the right course of action. In fact, there are quite a few things that you should never clean with bicarb - which is why it’s essential to keep this product away from your precious lawn and plants.

Weeds in between patio slabs

(Image credit: Getty Images)

This is because the high salt content in baking soda won’t just kill weeds. It will also kill any greenery that it comes into contact with, leaving you with dead grass and dried-up garden borders.

Instead, you should focus on learning the correct way to get rid of weeds in a lawn and using a plant-friendly alternative around other plants.

Thomas Hamilton from WeedingTech says, ‘Personally, whilst baking soda is a good option for tackling weeds, as is vinegar, nothing can beat doing it manually with some sturdy gloves and a shovel of some kind, digging or pulling them out by the root. It might take longer, but it's good exercise, and it should permanently kill the weed - if you can get all the roots out!’

This chemical-free option is echoed by John Clifford, the garden expert at Gardenstone. ‘​​For a more trustworthy but natural way to remove weeds, you should pull the weeds up by hand, or by using a weed removal tool,’ he urges. ‘Always try natural methods before you choose chemical weed killer, as weed killer can prove dangerous to wildlife and your garden environment".

What you’ll need


Does baking soda kill weeds permanently?

If used correctly, baking soda can kill weeds permanently and prevent their return. The baking soda completely dehydrates the weed, killing it in the process. And if you then pull out the whole weed by the root, it shouldn’t come back.

However, if you simply sprinkle baking soda on the weeds but don’t pull out the weed or the root, it’s highly likely that the weeds will come back with a vengeance.

How to use bicarbonate of soda to kill weeds?

If you want to kill weeds with baking soda, your best bet is to create a concoction of water and bicarb. And while you could then pour the mixture into a spray bottle and spritz the weeds, applying the concoction using a brush is much more effective.

After a few days, you should find that the mixture has dried out the weed, allowing you to pull it up at the root.

So, baking soda does indeed kill weeds - but you need to make sure it doesn’t kill anything else in your garden, too.

Lauren Bradbury

Lauren Bradbury is a freelance writer and major homes enthusiast. She graduated with a Bachelor’s degree in English and Creative Writing from the University of Chichester in 2016, before dipping her toe into the world of content writing. After years of agency work, writing everything from real-life stories to holiday round-ups, she decided to take the plunge and become a full-time freelancer in the online magazine world. Since then, she has become a regular contributor for Real Homes and Ideal Home, and become even more obsessed with everything interior and garden related. As a result, she’s in the process of transforming her old Victorian terraced house into an eclectic and modern home that hits visitors with personality as soon as they walk through the door.