How we test hedge trimmers

Hedge trimmers: How we test hedge trimmers

How we decide which hedge trimmers to test

Which? tests the best-selling hedge trimmers, the ones you will see most commonly sold from best-selling brands such as Bosch, Flymo, Ryobi and Stihl. We also look for newly launched or interesting models, particularly if they have innovative features.

To find out which ones did best in our tests, have a look at our Best Buy hedge trimmers.

What makes a Best Buy hedge trimmer?

Check out our video to see how a Best Buy hedge trimmer will make a real, practical difference to you. 


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Our testers cut 5m of conifer hedge with each hedge trimmer

Hedge cutter tests

Over the past few years we have asked more of the hedge trimmers we test. In 2012 we cut only conifer hedges. In 2013 we added deciduous hedges, and in 2015 we also cut laurel hedges. The deciduous hedges in 2013 were blackthorn and hawthorn, while we swapped to privet in 2015 as this is such a widely grown hedge.

We added these hedges as we know you have these in your gardens and also because each hedge presents a different challenge for the hedge trimmer.

• Conifer hedges have whippy growth that can be stripped by poor hedge trimmers.
• Privet can be hard to cut with a smooth, even finish if the hedge trimmer is not fast and sharp.
• Laurel hedges have thick, waxy leaves and thicker stems that some hedge trimmers find hard to cut and leave a ‘chewed’ look.

We have also increased the amount of hedge we cut to a minimum of 10m2 for each of the three hedges. This ensures none of the hedge trimmers are unfairly marked down for cutting an unusually thick part of any hedge.

Three experienced testers used each hedge trimmer. They time how long each hedge trimmer takes to complete the task and rate each one for the quality of finish and the ability to cut through thicker branches.

While we have refined our testing procedures over the years, our earlier test results still provide a good indication of how well these hedge trimmers were able to cut. Our ease of use tests have not changed and are directly comparable.

Which are the easiest hedge trimmers to use?

Three testers assess each hedge trimmer for ease of use, taking into account how easy they would be for an older or less able gardener to operate. 

They rated the machines on 18 criteria, including how easy they are to carry around, how comfortable the handles and switches are, how easy to use for vertical or horizontal cutting and whether noise, vibration, weight or balance are a problem. 

All our hedge trimmer reviews include all their scores for performance and ease of use.

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We time how long each cordless hedge trimmer cuts before it needs re-charging

Cordless hedge trimmer battery life

They ran the cordless trimmers continuously on a tougher twiggy hedge and timed how long the battery lasted. They also rated how easy the battery was to remove and refit. We test the battery as we carry out our cutting tests. We time how long the battery lasts on each of our hedges and then average the time before the hedge trimmer stops cutting effectively and work out how much hedge can be cut in this time.

We also rate how easy the battery is to remove and refit.

Hedge trimmer safety

We check hedge trimmers for electrical and mechanical safety. They should be designed in such a way that it's impossible to injure yourself in normal use. Features we look for include:

  • Two separate switches so you have to keep both hands on the machine.
  • The blades should stop the instant you release one of the switches, so touching a still-moving blade is impossible. 
  • The blade should have blade extensions – fixed teeth that extend well beyond the cutting teeth so you can’t do serious damage if you accidentally brush the trimmer against your leg.

Over the 30 years we’ve been testing hedge trimmers, safety features have improved considerably. In the early days we campaigned to improve safety features and these have now been incorporated into international standards and adopted by all manufacturers.

How Which? scores hedge trimmers

The score for corded electric hedge trimmers and petrol hedge trimmers is made up of 50% performance and 50% ease of use.

For cordless trimmers, battery life makes up 20%, as this is key to whether they are up to the job. Performance and ease of use each score 40% for battery models.

A corded electric trimmer has to score over 70% to be a Best Buy. Cordless trimmers are generally less powerful and petrol machines are heavier, noisier and more tiring to use. So cordless and petrol hedge trimmers must score more than 65% to be a Best Buy hedge trimmer.

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