How to kill weeds but not grass – the safest ways to avoid damaging your lawn

Wondering how to kill weeds but not grass?

Knowing when to use weedkiller on a lawn is one thing, but how can you make sure you aren’t damaging your grass at the same time? It can be tricky to know what will and won't harm your lawn.

Well, luckily, there are several ways you can get rid of weeds in your lawn without killing your grass. I spoke to lawn experts to find out exactly how to do it.

One of the safest ways to kill weeds but not grass? Weeding your lawn by hand.

Sure, it’s a bit of a slog – especially if you have a larger lawn – but manually removing weeds with a weeding tool will avoid the need for herbicides.

It isn’t a failsafe way to weed your lawn, though.

‘The safer option would be to remove them by hand, which will get rid of them for the time being, albeit most likely exposing some damaged lawn underneath,’ explains Cheryl Harper, managing director at Greensleeves.

‘But it is worth bearing in mind that, whilst this method will protect the rest of the lawn from too much wear and tear, this won’t stop weeds from growing back in the near future.’

The next best thing for lawns that are already overrun with weeds? Using a herbicide – but you’ll have to tread carefully, because not all herbicides are safe for grass, especially if you don’t use them properly.

‘If not applied correctly, these products could cause your lawn more problems,’ warns Cheryl. ‘If you are going to opt for a shop-bought treatment, read the label carefully and apply this when weeds are actively growing – in the spring or autumn – and avoid mowing for a couple of days before and after application.’

Selective herbicides are your safest bet if you’re wondering how to kill weeds but not grass. As a bonus, a lot of weedkillers come as a ‘weed and feed’ package, meaning they contain fertilisers that will actually boost the health of your lawn as well as killing weeds.

The gold standard, though, would be to combine lawn-safe herbicides with manual weeding. The earlier you remove weeds when you spot them, the easier it’ll be to keep on top of them.

‘To effectively kill weeds in your lawn without harming the grass, consider a combination of methods like hand-weeding and using selective herbicides,’ says Peter Chaloner, managing director of Cobra, one of the UK's leading brands of garden machinery.

Above all else, you’ll need to brush up on all the best lawn care tips.

‘The most effective method is through maintaining a healthy lawn through proper care,’ says Peter. ‘ A regular regime of fertilisation, scarifying, mulching, proper watering, and regular mowing can help prevent weeds from taking hold.’

It is No Mow May, though, so it's worth considering which weeds you can leave in the garden for the benefit of wildlife.

Combine manual weeding with a safe, selective herbicide and make sure your lawn is in tip-top condition, and you should start winning the fight against weeds.