Guide written by:
Holly, self-taught DIYer, Cardiff
Great for breaking down branches after pruning, garden shredders are essential for reducing your garden waste. Choose from electric or petrol-powered models equipped with different shredding systems, power ratings and features such as collection boxes. Read on to find the right garden shredder for you.
- Power rating
- Blade disc
How to choose a garden shredder
Size of garden
Maximum branch diameter
Branches (no hardwood)
300 to 500 m²
Electricity or petrol
38 to 45 mm (no hardwood)
Branches, hedges, shrubs (medium hardwood)
Clean blade and maintain motor
≥ 500 m²
≥ 50 mm
Branches, fruit trees (very hard wood)
Motor maintenance (oil, draining, clean filter, spark plug)
When choosing any type of garden shredder, you should pay close attention to the following points:
- noise level, generally between 85 and 105 dB;
- collection box for collecting shredded material;
- type of hopper, ideally with large opening;
- weight, a lightweight shredder will be easier to move around;
- a folding model will take up less room.
Parts of a garden shredder
Electric vs. petrol-powered garden shredders
A garden shredder consists of a loading hopper that guides material into a shredding mechanism designed to break down your waste into more manageable pieces. Garden shredders fall into two broad categories: electric or petrol-powered. To work out which option is best for you, you just need to think about the size of your garden.
Electric garden shredders
Electric garden shredders are powered by mains electricity, and are suitable for maintaining small to medium-sized gardens.
The power rating of these machines ranges from 2000 to 3000 W, which is sufficient to break down branches of up to 45 mm in diameter.
Petrol-powered garden shredders
Petrol-powered garden shredders are better suited to large gardens that require regular maintenance. More powerful than electric models, these machines offer around 4.5–9hp (the equivalent of 3300–6600 W).
A petrol-powered garden shredder can get through much larger, denser material, including branches of up to75 mm in diameter. These machines should be used and maintained with care as they often feature a powerful, 4-stroke engine. In short, be sure to keep your instruction manual handy!
Choosing a shredding system
Each garden shredder features its own type of shredding system, which should be chosen according to your specific needs. In order to make the right decision, you'll have to think about the material you want to shred and the size of your branches.
There are four basic shredding systems: blade disc, rotor, turbine-cut and roller.
If you have a garden that spans less than 300 m2 and only needs the occasional tidying up, go for a shredder with a blade disc. This system will also work if you only want to break down leaves, household waste and small branches of up to 35 mm (and you don't plan on chipping any hardwood).
Blade discs boast a high RPM of around 2000 to 4500 and produce a very fine shredded material. The only downside of this system is that it is noisy and does tend to jam.
This system is best suited to large gardens containing branches of up to 50 mm in diameter. These machines tend to have a fairly low RPM meaning they will churn away slowly but surely!
A revolving cog system is used to shred tough hedges and shrubs to create larger chippings that will be perfect for the compost heap. A rotor system will jam less often, is quieter than a blade system and is suitable for regular use.
A turbine-type system is like a rotor but more efficient and able to break down very hard woods, such as fruit trees and thick undergrowth with big branches.
The system of choice for the most powerful shredders, rollers can break down big branches measuring up to 50 mm.
However, the rollers do tend to jam.
Picking a system based on desired result
Alternatively, you can pick your garden shredder based on the result you're after:
- mulch is produced by blade discs;
- compostable material is produced by turbine-cut or rotor systems;
- chippings are produced by all types of shredders.
Garden shredder power rating
The amount of power you need from your garden shredder depends on the size of the branches you want to cut as well as the type of shredding system on offer. The bigger your branches, the more powerful the machine you will need – and the less you'll want to run into jamming issues. Refer to the following guidelines for an idea of what to look for in terms of power:
- Branches ≤ 35 mm: electric shredder with blade disc shredding – 2000 to 2200 W.
- Branches 38 to 45 mm: electric shredder with rotor or turbine-type shredding – 2200 to 2500 W.
- Branches > 50 mm: petrol-powered shredder – equivalent of 3300 W+.
Main characteristics of a garden shredder
Even a relatively lightweight garden shredder (~15 kg) will be tricky to move around.
Generally speaking, the more powerful the garden shredder, the heavier it is. If you find yourself trying to decide between a couple of models, go with the one equipped with wheels.
The hopper is located at the top of the crusher and is used to feed in branches or any other material you want to shred.
A funnel-shaped chute facilitates feeding and speeds up chipping.
Built-in collection box
Some garden shredders come with an integrated collection box. Blade disc shredders are often equipped with an ejector chute at the front.
Rotor or turbine-type garden shredders generally have a built-in collection box.
Noise level is indicated in decibels (dB) and ranges from 85 to 105dB. Electric models are less noisy and those equipped with a rotor system will be even less so; as they turn more slowly than other models, they have a maximum noise output of around 88 dB. No matter which model you choose, you should always wear hearing protection.
Ease of use
Electric shredders are easier to start up as they don't require any specific settings. In terms of convenience, blade disc and rotor systems will require the use of a push stick to feed the branches into the shredding system.
This is something you won't really have to consider with a turbine system as it's naturally more resistant to jamming.
Ease of storage
As garden shredders do take up a fair amount of room, opt for a folding model, if possible. You'll appreciate the extra room if your garden shed is already packed to the brim with appliances like hedge trimmers and lawnmowers!
Caring for your garden shredder
Maintaining a petrol-powered shredder
If you go for a petrol-powered model, be prepared to carry out the following maintenance tasks:
- cleaning and/or changing the spark plug on a regular basis and checking the electrode gap;
- cleaning the air filter and carburettor (if required);
- mixing fuel for a 2-stroke engine (oil + petrol) according to the manufacturer's instructions;
- keeping a 4-stroke engine topped up with fuel and changing the oil on a regular basis according to the manufacturer's instructions.
Routine maintenance for all shredders
Before carrying out any maintenance tasks, be sure to turn off your shredder (unplugging it, if necessary) and wait until it has stopped operating.To avoid cutting your fingers, never touch the blade directly with your hands; use a brush instead.
The blades of your shredder will need to be sharpened when they are no longer able to cut properly.
Generally speaking, you will have to lubricate all moving parts (wheels, etc.) and clean all motor components of shredded material including guards.
Preparing your garden shredder for winter will involve carrying out routine maintenance tasks and checking the engine (drain oil, check spark plug, etc.).
Your shredder should be covered with a protective cover and stored away any sources of humidity (in a garden shed or garage, for example).
Final tips for using a garden shredder
No matter how safe the manufacturer says your garden shredder is, be sure to always wear protective gear including gloves, goggles and ear protectors.
If your shredder jams, turn it off (unplugging it, if necessary) and wait until everything has stopped moving before unblocking the system using a brush and gloves.
Garden shredders must be turned off when not in use.
Avoid shredding softwood to keep your blades in good condition.
Guide written by:
Holly, self-taught DIYer, Cardiff, 22 guides
First of all, my studies have nothing to do with decoration or DIY as I was specialised in management. My passion in DIY started 5 years ago (very recently!) Everything started when we bought a house to renovate from floor to ceiling. As I’m a self-taught person, I started working on different house project both inside and outside. My husband helped me but the student soon overtook the teacher! And as there are a lot of green spaces in Creuse, gardening tools have no secrets for me. My friends and family often come to me for advice when it comes to DIY. Today, I want to share this with you!