Line trimmers – also called whipper snippers, edge trimmers or lawn trimmers – are used for more than just Versailles-style, precision-perfect lawn edges or garden borders. You can go crazy with horizontal trimming along fences and walls, cut wild patches of long grass down to size and even mow reasonable-sized areas of lawn.
Petrol models are the best choice for really big areas or for contractors, as you can refuel them quickly and they're the most effective at cutting through swathes of long tough grass. Here's what to consider when buying:
Straight or curved shaft?
Petrol trimmers with curved shafts tend to be more common in the domestic trimmer range. Straight-shaft petrol trimmers, often referred to as brush cutters, tend to be more powerful and heavy-duty than curved-shaft models, and can also have a longer reach.
A transparent fuel tank makes it easy to see when you're running low on petrol; it also makes refuelling easier as you can see how much petrol to pour in. Most petrol models have two-stroke engines, which are still the most common type of small petrol engine; that means you'll need to mix the fuel. Two-stroke oil for the fuel mix can be bought at hardware and auto stores, mower shops and petrol stations. Four-stroke engines can be more convenient as they use straight unleaded petrol and emit less pollution, too.
A clutch will stop the cutting head from spinning when the motor idles - this is safer while you're moving between areas. On clutchless models the line continually rotates when the motor's running, so be careful if you walk around while it's switched on.
Think carefully about the size and shape of your lawn, the type of grass, and the sort of edges and obstacles it contains (paths, walls, garden beds, trees, and so on).
Electric and cordless battery-powered models tend to have less cutting power than petrol but can be much more convenient for smaller yards. They're easier to start than petrol models and also quieter to use.
Corded electric trimmers require dragging an extension cord behind you, which is potentially dangerous - so they're only suitable for a small backyard. They aren't as popular now that cordless models have improved in performance and our tests now focus on petrol and cordless models only.
Electric and cordless models' motors are usually at the cutting head rather than the handle end; with no actual drive shaft, the length of the shaft can often be adjusted.
With a cordless model, consider getting a spare battery; it can be handy if you have a larger yard that can't be covered with one battery charge, or if you get out the trimmer only to realise you didn't recharge it after the last use.
There are two numbers to consider when it comes to batteries:
- Voltage (V), which indicates the power of the battery. 18V batteries are common, but many models now come with batteries rated at 36V, 40V, 56V and even 82V. Our tests find that a higher voltage usually leads to better cutting performance.
- Capacity (amp hours or Ah) which indicates the relative running time; the bigger the capacity, the longer the running time. While a 1.5Ah or 2.0Ah battery is probably enough for a typical yard, look for larger capacities if you need longer running time.
Line trimmers typically cost around $200 to $300, but prices can range from $60 to $900+.
Mounted around the rear of the cutting head, this reduces the amount of debris flying around. Some guards can limit your view of what you're cutting. All the models we've tested have one.
Line length-limiting blade
Many models have a small blade mounted on the safety guard that cuts the trimming line off at the correct length (any models that don't have this usually have blades instead of a line, so they don't need the line-length limiter). An over-long line can overload the motor.
A harness that clips onto the shaft supports the trimmer's weight. It's usually an optional extra, but is not available to all trimmers.
Found on most trimmers, the "bump feed system" is easy to use – simply tap the cutting head on the ground when you need more line to feed out. An automatic system sends out more cutting line when it gets too short, while a manual feed requires you to turn off the trimmer and pull or unwind the line inside the head.
A cutting head that can positioned horizontally for grass cutting or vertically for edging. Without this feature, you'll need to turn the whole tool for vertical trimming, which can be less convenient.
If you are looking for super-straight edges, look for a model with an edging guide.
Fitting new cutting line (re-spooling) can be one of the fiddliest tasks when it comes to using a line trimmer. A trimmer with a single cutting line is easier to re-spool than one with twin lines, though the latter can give better cutting performance.
A wide diameter is useful if you want to trim open areas. Petrol line trimmers usually have a wider diameter than the cordless and electric models.
Most models on test have an adjustable handle that can be rotated on the shaft when you turn the trimmer over, to change from horizontal trimming to vertical edging (on some models, the cutting head can be rotated instead for the same purpose).
Adjusting tools such as a spanner are often included as standard. Some trimmers have other accessories (usually as optional extras), such as brush-cutting blades or extra edging heads.