Which grass trimmer brand is most reliable?

We investigated the performance and reliability of some of the most popular grass trimmer brands, including Stihl, Makita, Ryobi and EGO.

In our unique gardening product survey, we asked more than 7,635 Which? members and members of the public if they were happy with their grass trimmer and if they’ve experienced problems, so you can see which brands are worth the money.

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Which grass trimmer brands develop the fewest faults?

This table summarises what we found about how quickly different brands develop faults or break down based on grass trimmers bought in the past five years.

As you can see, brands differ when it comes to the chance of developing faults – the best saw only 2% of their models develop a fault in the first five years, while the worst saw a rate over 17%

Join Which? to get access to the table below, plus all our Best Buys and grass trimmer reviews. We’ve tested grass trimmers from brands including Bosch, Flymo and Gtech, but only the very best make a Best Buy.

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Looking for a new grass trimmer? Take a look at our round-up of best grass trimmers on test.

Which grass trimmer brands do owners recommend?

As well as faults, our survey also revealed which grass trimmer brands owners feel happy with – and which they would recommend to a friend.

These results are shown as each brand’s Customer Score and are based on grass trimmers bought in the past five years.

Join Which? to get access to the table below, plus all our Best Buys and grass trimmer reviews. We’ve tested grass trimmers from brands including Bosch, Flymo and Gtech, but only the very best make a Best Buy.

Common grass-trimmer problems

Corded, cordless and petrol grass trimmers operate quite differently, so it's unsurprising they encounter different problems.

The line feed breaking is a common problem. This is annoying, but can be fixed on the spot. Read our expert guide on how to avoid line-feed problems for more details.

Luckily, most of the top faults are also fixable, or at least won't result in the total breakdown of your trimmer.

Top three common corded grass trimmer faults

1. 32% - Line feed malfunctioned The line feed that's used to cut your grass can break or become jammed. You can usually fix it manually. 
2. 13% - Motor failed This could be a complex issue and there probably isn't much you can do yourself unless you're an expert. Instead, contact a qualified engineer to inspect and repair the grass trimmer for you. 
3. 11% - Electrical failure As above, if you're not confident enough to look into this yourself, take your trimmer to a garden machinery specialist or contact the manufacturer to look at having it fixed.

Top three common cordless grass trimmer faults

1. 17% - Line feed malfunctioned The line feed that's used to cut your grass can break or become jammed. You can usually fix it manually.
2. 16% - Battery would not hold charge Lithium-ion batteries eventually lose their ability to hold charge. Store the battery separately from your trimmer and with a minimum of 40% charge remaining.
3. 14% - Battery failed to charge Before you buy a replacement battery, if you have any existing tools from the same manufacturer, check if theirs are compatible. It's useful to have two batteries, so when you're carrying out jobs that will take longer than one battery charge to finish, you have another on standby, ready to swap in.   

Ready to cut the cord? Take a look at our cordless grass trimmer and strimmer guide.

Top three common petrol grass trimmer faults

1. 19% - Engine would not turn over If you're not confident enough to look into this yourself, take your trimmer to a garden machinery specialist or contact the manufacturer to look at having it fixed.  
2. 9% - Pull cord broke or jammed Another fault that may require specialist attention.
3. 8% - Line feed malfunctioned The line feed that's used to cut your grass can break or become jammed. You can usually fix it manually.

Which grass trimmer brands offer the best guarantees?

Most grass trimmer brands such as Mac Allister, Stihl, Black & Decker and Cobra offer product guarantees of at least two years, but there are a handful of popular brands that offer longer cover, including:

• Bosch - two-year guarantee, rising to three years if the garden appliance is registered with Bosch.
• Flymo - a 'POWER FOR ALL' battery-operated product, comes with a two-year warranty, rising to three years if the product is registered with Flymo after purchase.
• Mountfield - any machine bought after the 1 October 2023 will qualify for a five-year extended warranty.
• EGO - five-year warranty for domestic use.

How we calculate the best and worst brands

Which? has a wealth of information on the UK’s favourite garden tool brands. Every two years, we ask Which? members and the public to tell us about the garden products they own - from how likely they'd be to recommend a brand to whether they experienced any faults with it. This year, 7,635 people told us about their products. We calculate a brand's customer score based on the results of our biennial survey.

Our product experience surveys, combined with our extensive lab tests, mean we can recommend the best grass trimmer you should buy.

To find out more about our rigorous lab tests and what makes a Best Buy, head to our how we test strimmers and grass trimmers page.