Best String Trimmer: How to Choose the Right One for Your Yard

Battery, corded, petrol or manual – which type do you need?

Most string trimmers on the market fall into four main types. The difference is the power source, and it decides both how long you can cut in one session and how far from the house you can realistically work.

Cordless (battery) – the default for most yards

A cordless trimmer has no cable to manage, moves easily between different parts of the yard, and comfortably handles the edges, borders and awkward corners of a typical home lawn. Runtime varies between models, but most manage 20–40 minutes of continuous cutting on a charge, which covers most yards without a mid-job battery swap. If the trimmer shares a battery platform with a mower or other tools you already own, it's often cheaper, since you're only paying for the bare tool.

Corded (mains) – unlimited runtime at a lower price

A corded trimmer never runs out of power mid-job and usually costs less than an equivalent battery model. The trade-off is the cable itself: you need to keep track of where it is, avoid cutting through it by accident, and have an outlet within reach. That makes it less practical for a large yard, but a solid choice for a small lot close to the house.

Petrol (gas) – the most power for large areas and tough weeds

A petrol trimmer is the most powerful type and keeps a steady pace through thicker grass and tougher weeds without bogging down. It's also heavier, noisier and needs more upkeep — fuel mixing, spark plugs, air filters — than battery or corded alternatives. It pays off mainly on larger properties, long fence lines, or if you're maintaining more than one yard.

Manual grass shears – quiet precision for the last few details

Manual grass shears, with two blades that meet like scissors, need no charging, weigh almost nothing, and disturb neither neighbours nor nesting birds. They're far too slow for a whole lawn's edges, but perfect for the last few details around a single plant, a paving stone, or right up against a border where a powered trimmer easily takes off too much.

Good to know. If you only have room for one trimmer, make it a cordless model with nylon line. It handles the routine edging most yards actually need without cable hassle or gas maintenance, and you can add a hedge trimmer for hedges and manual shears for the finest detail work later.

Line or blade – what should the trimmer cut with?

Most string trimmers ship with nylon line as standard, but many models also accept a plastic blade or small knife attachment instead. The choice affects both what the trimmer can handle and how often you need to replace consumables.

Nylon line – flexible and gentle on everything around it

Line spins fast enough to cut grass and soft weeds through sheer mechanical force. It flexes around stones, fence posts and tree trunks instead of bouncing or jamming, which makes it far gentler on both the trimmer and its surroundings than a rigid blade. The trade-off is that line wears down and needs feeding or replacing regularly, more often against thicker growth.

Most trimmer heads feed new line one of two ways: bump feed, where tapping the head lightly against the ground releases a spring-loaded mechanism that lets out more line, or auto feed, which senses when the line gets too short and feeds automatically. Auto feed is more convenient but uses line somewhat faster, since the mechanism tends to feed out more than strictly necessary rather than too little.

Plastic blades and knives – for tougher weeds and light brush

A plastic blade, often three or four rotating fins, handles tougher weeds and thin brushy growth better than line without wearing down as quickly. It also gives a slightly rougher cut and bounces more readily off hard obstacles like stones or fencing, so it suits open areas better than tight trimming near walls, fences and tree trunks.

If you're mostly edging lawns and cutting light weeds, line is all you need. If you deal with a lot of weeds along a fence line, ditch or the edge of a wild patch, it's worth choosing a trimmer that accepts a plastic blade, or at least one rated for a thicker line diameter.

String trimmer line thickness that actually matters

Line thickness, measured in millimetres or inches, decides how coarse the growth a trimmer can actually cut without the line simply whipping past without biting in. Thinner line is quieter and easier on the motor but wears out faster against tough growth. Thicker line handles more but needs a stronger motor to keep up its speed.

Line shape matters too. Round line is standard, quiet and handles most jobs fine. Square or twisted line with sharper edges cuts coarser weeds slightly more effectively, but wears faster and runs louder. If the line that came with the trimmer has worked fine so far, there's rarely a reason to switch shapes — thickness makes the bigger difference.

Good to know. Keep a spare spool of line, or a pre-loaded head, on hand at all times. Line snaps mid-job more often than you'd expect, especially against stone edging, and swapping a spool on the spot beats stopping the job to buy more.

String trimmer or brushcutter – where's the line?

Plenty of buyers pick up a heavy-duty string trimmer expecting it to handle everything in the yard, then feel let down when it neither cuts through real brush nor gives a tidy result on ordinary lawn edges. The tools are built for different jobs, and keeping them straight saves both time and frustration.

A string trimmer is built first for finishing lawn edges and reaching where the mower can't — a lighter tool with line or a plastic blade that handles grass and softer weeds. A brushcutter is a different category entirely: a stronger motor, a rigid shaft, a shoulder harness, and the option to fit metal blades that cut through real brush, dense growth and even light sapling stems. It's heavier and pricier, but does work an ordinary string trimmer never gets close to.

If you have an ordinary yard with a lawn, borders and a fence, a string trimmer covers nearly everything. If you're dealing with a vacant lot, a ditch, an old meadow or ground that's been left to grow wild for years, a brushcutter is the right investment from the start, rather than pushing a string trimmer past its limit every time.

Common mistake. Running a string trimmer through real brush just because you already own one, instead of accepting that the job needs a brushcutter. The result is a poor cut, wasted line, and a motor working far harder than it should.

Swath, voltage and runtime – what do the numbers mean?

Beyond the cutting head, three numbers are worth comparing between models: cutting swath, battery voltage, and battery capacity. Together they decide how fast the job goes and how long you can work before the battery runs out.

Cutting swath — how wide a strip the trimmer covers per pass — typically runs 23–35 cm (9–14 in) on cordless models. A wider swath covers a large area faster but makes the trimmer somewhat clumsier to steer in tight corners and close between plants.

Battery voltage says something about power but not the whole story on runtime. Entry-level models often sit around 18–20V, while more powerful trimmers run up to 36–40V or beyond. What actually decides how long you can work is battery capacity, measured in amp-hours (Ah) — a 4 Ah battery lasts roughly twice as long as a 2 Ah battery at the same voltage and load.

An ordinary home yard rarely needs more than 20–30 minutes of continuous trimming, which most batteries handle without issue. If you have a large property or a lot of edging to get through, it's worth either choosing a higher-capacity battery or buying a spare to swap in, rather than stopping the job halfway through to recharge.

Safety gear you actually need

The cutting head spins fast enough to fling stones, gravel and cut plant debris in every direction, often without warning. The right gear is the difference between a straightforward afternoon job and a trip to urgent care.

Safety glasses are a minimum, not a suggestion. Small stones struck by the line or blade can fly off with surprising speed, and eyes sit in the line of fire more often than most people assume. Sturdy shoes, ideally with a protective toe, and long trousers protect feet and legs from the same thing. Sandals and shorts have no place in trimming, however warm the afternoon is.

Keep a solid distance from other people, pets and parked vehicles while trimming — flying gravel can cause real damage or scratches over surprising distances. Check that the trimmer's debris guard, the curved plastic shield above the cutting head, is properly fitted too. It's there for a reason: to catch some of what would otherwise fly straight back at you.

Don't wear loose clothing, scarves or jewellery that could catch in the spinning head. Always switch the trimmer fully off, not just release the trigger, before clearing grass or weeds that have wrapped around the shaft or head.

Common mistake. Trimming near a gravel path or paved area without safety glasses. It's one of the most common causes of minor eye injuries in the yard, and one of the easiest to avoid entirely.

Weight, shaft and ergonomics – what shows up after an hour?

A trimmer that feels light in your hands for a minute in the shop can feel considerably heavier after forty minutes of trimming around the whole yard. Shaft design and balance matter more than most buyers expect.

Straight shafts are more common and give better reach under shrubs and along borders, while curved shafts sit slightly closer to the body and can feel more relaxed to hold during longer sessions. A telescopic or adjustable shaft lets you match the trimmer's length to your own height, which matters a lot if more than one person in the household shares the trimming.

Most trimmer heads also rotate roughly 90 degrees, turning the tool into an edger for a clean, straight line along the lawn — handy if you'd rather skip buying a separate edging tool just for that. A handle that adjusts in height makes it easier to find a comfortable grip regardless of who's holding the trimmer.

Balance matters at least as much as total weight. A trimmer with the battery set far back can feel more tiring to hold steady out in front of you than a lighter model with more even weight distribution. It's worth holding the trimmer out at arm's length in the shop for a moment before deciding, the same way you would with a hedge trimmer.

Good to know. A shoulder strap takes real strain off your arms during longer sessions and is worth checking on heavier battery models and petrol trimmers. On a light trimmer used for short sessions, it's rarely necessary.

What should you actually pay for a good trimmer?

Prices for string trimmers vary a lot by power source. The difference is rarely just the brand — it usually comes down to motor power, battery capacity, cutting swath and how much maintenance you avoid.

A trimmer under £70 ($90) is plenty if you have an average yard and trim a couple of times a month during the season. What drives up the price further up the range is usually a stronger motor, bigger battery capacity, wider cutting swath and better ergonomics — not the brand itself. If the trimmer shares a battery platform with tools you already own, such as a mower or other garden equipment, you can often buy just the bare tool for less, without battery or charger.

Good to know. Compare the warranty on the motor or battery specifically, not just on the product as a whole. Two years on the whole trimmer but only one on the battery is more common than you'd expect, and the battery is often the priciest part to replace.

How do you look after a string trimmer so it lasts?

Care affects lifespan at least as much as price does. A mid-range trimmer that's cleaned after every use often outlasts an expensive one left with dried grass and dirt packed into the head over winter.

Brush or wipe grass clippings off the head and shaft after every session, especially around the vents that cool the motor. Damp grass left to dry in place gets considerably harder to remove and can encourage rust on metal parts over time. Check that the debris guard and any fasteners are still secure while you're at it.

Refill or replace the line before it runs out mid-job, and keep a spare spool at home so you're never caught short. For battery models: don't leave the battery fully discharged before winter storage, and check the manufacturer's guidance on the right charge level for long periods of storage, since the wrong level can shorten battery life significantly.

Petrol trimmers also need the fuel drained or run dry before winter storage, since old fuel can gum up the carburettor by spring. Check the spark plug and air filter once a season too — it's usually a cheap fix that extends the motor's life considerably.

Common mistake. Putting the trimmer away in the shed at the end of the season with grass clippings still packed into the head and shaft. Dried plant matter holds moisture, which is a common reason metal parts start rusting unnecessarily by the following season.

How to choose a string trimmer, step by step

1. Work out what you're actually cutting. Lawn edging alone points to thinner line and a smaller swath. Heavy weeds or longer grass need thicker line or a plastic blade option.
2. Decide whether the job really needs a brushcutter. Genuine brush and dense growth are handled better and more safely with the right tool from the start.
3. Pick the power source based on your yard's size. A small lot near an outlet suits corded. Freedom to move around the whole property suits battery. A large area or a lot of edging suits petrol.
4. Match line thickness and swath to the job. Use the table above instead of guessing from the size or name of your lawn.
5. Test the weight and balance. Hold the trimmer out at arm's length in the shop for a moment, not just resting on the counter.
6. See if it shares a battery platform with tools you already own. That can cut the price significantly if you already have compatible batteries.
7. Check whether the head rotates for edging. It can save you buying a separate tool just for straight lawn edges.
8. Buy the safety gear at the same time. Safety glasses and sturdy shoes cost a fraction of the trimmer but make the job noticeably safer.

Common mistakes when buying a string trimmer

• Choosing line that's too thin for tough weeds. The line snaps repeatedly instead of cutting through the growth.
• Buying on voltage or brand name instead of matching the actual job. A powerful motor doesn't help if the line is still too thin.
• Forgetting about runtime on battery models. A large yard can need more than one charge, which is worth knowing before you're halfway done.
• Skipping safety glasses. Most string trimmer injuries come from flying stones and gravel, not the line or blade itself.
• Forcing the trimmer through brush it isn't built for. The result is poor and wears out both line and motor unnecessarily — a brushcutter is the right tool for that job.
• Missing that the head rotates for edging. Plenty of buyers only discover the feature after buying a separate edging tool they didn't need.

Frequently asked questions

What line thickness do I need for an ordinary lawn?
1.6–2.4 mm (0.065–0.095 in) covers lawn edges and lighter weeds well. Thicker line, 2.7 mm (0.105 in) and up, is only needed once you're regularly cutting tougher growth like nettles or dense weeds.

What's the difference between trimmer line and a plastic blade?
Line flexes around obstacles like stones and posts and is gentle on its surroundings, but wears faster against tough growth. A plastic blade handles coarser weeds better but bounces more easily off hard obstacles and suits precision work near walls and fences less well.

Should I choose battery or corded for my trimmer?
If your yard is small and close to an outlet, corded is often cheaper and perfectly adequate. If you need to move around the whole property or dislike managing a cable, battery is more convenient, as long as the yard isn't so large that runtime becomes a limitation.

When do I need a brushcutter instead of a string trimmer?
Mainly for real brush, dense growth, or land that's been left to grow wild for several years. An ordinary yard with a lawn and borders is handled by a string trimmer in nearly every case.

How wide a cutting swath do I need?
23–30 cm (9–12 in) suits most home yards and gives good control in tight corners. A wider swath, up to around 35 cm (14 in), covers large open areas faster but gets clumsier to steer close between plants.

Can I use a string trimmer as an edger?
Yes, most trimmer heads rotate roughly 90 degrees, which lets you run it along the lawn's edge for a clean, straight line without buying a separate edging tool.

How often do I need to replace the line?
It depends entirely on how much and what you're cutting. Lawn edges wear line the least, while dense weeds and contact with stone edging can use up a spool in a single session. Always keep a spare on hand.

How long does a good string trimmer last?
A mid-range trimmer or better, cleaned regularly and stored dry, typically lasts seven to ten years without major problems. The battery on a cordless model is usually the part that needs replacing first.

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