How Does A Hedge Trimmer Work?

Parts of a Hedge Trimmer

In order to understand how a hedge trimmer works, it is important to look at its different parts and the role they play. While hedge trimmers come in different types, shapes and sizes, there are some essentials that all hedge trimmers share. As you are about take a look this article, spare some time and go through our reviews on some of the best corded, cordless and gas hedge trimmers out there before you buy one.

Here is a look at several important components that will help you understand how a hedge trimmer works.


Hedge trimmers can have one of two different types of power sources: electricity or gas. The motor for gas-powered and electric-powered hedge trimmers function on different power sources but they perform the same basic function of providing power to the machine.

Gasoline Engine

Gas engines use a combination of fuel and oil to give a hedge trimmer the power it needs to function. Gasoline engines produce a lot more power compared to electric motors, and that is why they are able to take on some excessively tough hedge trimming tasks.

A gas-powered hedge trimmer works by combusting fuel like an automobile engine to generate the oscillations needed to move the blades. The downside of a gas hedge trimmer is that it is heavier than an electric hedge trimmer and more expensive to operate, due to both the cost of the fuel, and also the regular maintenance the gas engine needs to keep it in tip-top condition.

Electric Motor

Electric-powered hedge trimmers are lightweight, more affordable and quieter than gas-powered hedge trimmers. While gas-powered hedge trimmers require fuel to operate, electric- powered hedge trimmers rely on either battery or being plugged into a power supply.

An electric-powered hedge trimmer works by using the electrical current provided by either the mains connection or the battery, to power the motor, which provides the oscillations that the blades need.

Electric motors are less powerful than gas, but also quieter. The reduced power makes electric trimmers less effective against particularly thick branches – if you regularly need to cut through branches more than around 1/2″ thick, you’d be better off with a gasoline hedge trimmer.

One further advantage of electric hedge trimmers is they don’t produce any emissions at the device.


Electric-powered hedge trimmers come in two different types. They can be either corded or cordless. Corded hedge trimmers require a constant connection to a power source to function. Cordless hedge trimmers use batteries as their power source.

The main downside of using a cordless hedge trimmer is that you have to recharge or replace the batteries when needed. Corded hedge trimmers can’t be used more than 100′ from a power source, and you’re also at risk of cutting through the power cord.

Cordless hedge trimmers tend to be heavier than corded models, as you have to carry the power source (battery) around with you.


To understand how hedge trimmers work, you need to know about the blades. Hedge trimmers comprise a large number of blades protruding from their body. They can be either on one side or on both sides like in the hedge trimmer shown in the image. This determines whether you can work in one direction or if you can take a sweeping approach.

Hedge trimmer blades can also be single- or double-action:

  • Single-action trimmers have one moving blade and one static blade
  • Double-action trimmers have two blades which move in opposite directions (think of them like scissors)

Double-action blades are claimed to cause less vibration, as the motions of the blades in opposite directions cancel each other out. Most modern hedge trimmers have double-action blades.

Residential hedge trimmers have short gaps between their teeth because they are more suited for less problematic branches. Commercial grade hedge trimmers have larger tooth gaps, so that they can tackle thicker and more unruly branches.

Read more on maintaining the trimmer blades for efficient performance.

Safety Features

Safety always comes first. Considering that a hedge trimmer has a lot of blades oscillating at a fast pace for cutting hedges, it is necessary to consider its safety features. They are an important part of understanding how a hedge trimmer works and how you should operate them.

In order to protect yourself from harm, hedge trimmers have auxiliary handles and blade guards. Other than that, one of the most important safety features is a lock button, which prevents the trimmer starting unless the lock is disengaged. Generally this means the trimmer will not start unless you press 2 separate buttons with both hands.

One further feature found in most higher-end hedge trimmers is a blade brake – this stops the trimmer almost instantly when you disengage the trigger.

Final Thoughts

Understanding different parts of a hedge trimmer will help you get a better understanding of how hedge trimmers work and how to use one. It is important to understand the tools you are using, how they function and their appropriate safety features. Not to mention, it will also help you decide on what type of hedge trimmer you need, and all the precautions you need to take in order to trim hedges safely.

If you are about to buy a hedge trimmer, make sure to go through our ultimate buying guide to help you choose one.


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Electric vs Gas Hedge Trimmers - October 30, 2019

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