The Complete Guide to Buying String Trimmers, Edgers and Brush Cutters

What String Trimmers Actually Do (and Where They Fit)

A string trimmer (also called a strimmer, line trimmer, or weed whacker depending on where you live) uses a rapidly spinning nylon line to cut grass, weeds, and light growth in areas a mower cannot reach — around fence posts, tree trunks, garden borders, walls, paths, and raised beds.

It is not a substitute for a mower (it cuts unevenly over large areas) and it is not a brush cutter (the nylon line cannot handle thick, woody stems). What it does brilliantly is finish the edges and awkward corners that a mower leaves behind, giving a garden its manicured, cared-for appearance.

At the lighter end, a domestic cordless trimmer tidies lawn borders in a few minutes. At the heavier end, a professional petrol brush cutter with a metal blade clears bramble, scrub, and saplings that would stop a mower dead. The equipment spans an enormous range — and the right choice depends entirely on what you need it to do.

Domestic String Trimmers

For most homeowners, a domestic-grade string trimmer is all that is needed. These tools handle lawn edging, trimming around obstacles, and light weed control in garden beds.

Battery (Cordless) Trimmers

Battery-powered trimmers now outsell petrol models for domestic use, and for good reason. They start at the press of a button, run quietly, produce no fumes, require almost no maintenance, and are light enough for extended use without fatigue.

Typical specifications: 18V–56V battery platforms. 25–35 cm (10–14 inch) cutting swath. Weight 2.5–5 kg (5.5–11 lb) including battery. Runtime 20–45 minutes per charge depending on battery capacity and workload.

Strengths: Instant start — no pull cord, no choke, no fuel mixing. Quiet enough to use early morning or evening without disturbing neighbours. Light and well-balanced. Batteries are typically shared with other tools on the same platform (mower, blower, hedge trimmer, chainsaw), making the ecosystem cost-effective.

Limitations: Runtime is finite — a single charge handles a small to medium garden comfortably, but larger properties may need a spare battery. Power is adequate for grass and light weeds but insufficient for thick, woody growth. In very dense or wet grass, domestic cordless trimmers can bog down.

Best for: The vast majority of homeowners with small to medium gardens who need neat edges, tidy borders, and clean lines around paths and beds.

Corded Electric Trimmers

Corded trimmers plug into a household socket via an extension cord. They are the lightest, cheapest, and simplest type — unlimited runtime, no batteries to charge, no fuel to mix.

Strengths: Very affordable. Lightest weight of any powered option (no battery or engine). Constant, uninterrupted power. Good for elderly or less physically strong users.

Limitations: The cord restricts range and creates a trip hazard. You must constantly manage the cord to avoid cutting through it — a genuine and common risk. Practical only for small gardens within extension cord range of an outdoor socket.

Best for: Small gardens, close to a power socket, where the cable is manageable.

Petrol (Gas) Trimmers — Domestic

Domestic petrol trimmers are heavier, louder, and more maintenance-intensive than cordless models, but offer unlimited runtime and greater power for larger areas and tougher growth.

Typical specifications: 25–30 cc two-stroke engines. 35–40 cm (14–16 inch) cutting swath. Weight 4–6 kg (9–13 lb). Curved or straight shaft.

Strengths: Unlimited runtime (refuel and continue). More power than most domestic cordless models. Independent of electricity supply.

Limitations: Pull-start mechanism (which can be difficult — see the dedicated section below). Fuel mixing required (two-stroke oil and petrol in the correct ratio). Loud — hearing protection recommended. Heavier than cordless. Requires regular engine maintenance (air filter, spark plug, fuel system).

Best for: Larger gardens and rural properties where cordless runtime is insufficient and the extra power of a petrol engine is genuinely needed.

Edgers: Dedicated Tools vs Trimmer Conversion

Edging — creating a clean, defined line where lawn meets path, patio, or border — can be done with a string trimmer held vertically, or with a dedicated edger.

Using a trimmer as an edger: Most string trimmers can be rotated 90 degrees so the cutting head is vertical, allowing you to cut a neat edge along a hard surface. This works well for maintaining an existing edge. Some trimmers have a specific edging mode or guide wheel to help.

Dedicated edgers use a vertical blade (either a spinning disc or a small metal blade) to cut a clean trench along the edge of a lawn. They produce a sharper, more professional-looking result than a trimmer and are worth considering if you have extensive paved borders or take particular pride in immaculate lawn edges.

For most homeowners, a string trimmer used vertically is entirely adequate for edging. A dedicated edger is a refinement, not a necessity.

Commercial and Professional Equipment

This is where string trimmers become serious tools — heavier, more powerful, significantly more expensive, and designed for daily professional use or demanding domestic situations that go well beyond tidying lawn edges.

Professional String Trimmers

Professional-grade trimmers are built for landscape contractors, groundskeepers, and property owners with large or demanding sites. They feature more powerful engines (or higher-voltage battery systems), heavier-duty construction, bike-handle or loop-handle configurations for extended use, and professional harness attachment points.

Petrol professional trimmers typically run 30–45 cc two-stroke engines, produce wider cutting swaths (38–45 cm / 15–18 inches), and use thicker cutting line (2.4–3.3 mm). They are designed to run for hours at a time, day after day. They are louder, heavier, and more powerful than domestic models. Build quality is substantially higher — metal gearboxes, anti-vibration systems, heavy-duty clutches, and replaceable components that can be serviced rather than discarded.

Battery professional trimmers represent the fastest-growing segment of the market. Models from the established professional brands now deliver cutting performance comparable to mid-range petrol trimmers — the brushless motors provide excellent torque, the instant throttle response is actually smoother than petrol, and the absence of vibration from a combustion engine reduces operator fatigue dramatically.

The cutting performance is genuinely impressive. The problem is runtime.

Brush Cutters: When Nylon Line Is Not Enough

A brush cutter looks similar to a heavy-duty string trimmer but accepts metal cutting blades in addition to (or instead of) a nylon line head. The metal blade — typically a three-tooth, four-tooth, or circular saw blade — cuts through material that would wrap around or snap nylon line: brambles, thick weeds, scrub, bracken, nettles, small saplings, and overgrown vegetation.

Brush cutters are essential for land clearance, paddock maintenance, orchard work, path clearing through overgrown areas, and any situation where the growth is too thick and woody for nylon line.

Key difference from a trimmer: The metal blade demands a more robust machine — heavier gearbox, stronger shaft, anti-vibration system, and a professional harness to support the weight and manage the forces. A brush cutter blade spinning at full speed carries significant energy; the tool must be built to handle it safely.

Safety equipment is non-negotiable: Face visor, hearing protection, stout footwear (steel-toe boots), long trousers, and gloves. A professional harness distributes weight and provides a quick-release mechanism in case of emergency. Metal blades can throw debris (stones, fragments of woody material) at considerable velocity — face protection is essential, not optional.

Professional Battery vs Petrol: The Honest Comparison

This is the section where most buying guides gloss over the reality. The truth is nuanced and worth understanding before you invest.

Cutting performance: Modern professional battery trimmers and brush cutters deliver cutting power that matches or approaches petrol models in the 30–40 cc range. For nylon line work, the difference is negligible. For metal blade work, the very highest-output petrol models (45 cc and above) still have an edge in sustained heavy cutting, but the gap is closing with each generation.

Weight and ergonomics: Battery models are generally lighter than equivalent petrol machines (the battery weighs less than a full fuel tank and engine). The absence of engine vibration is a significant comfort advantage during extended use. Less vibration means less fatigue, fewer breaks, and reduced risk of hand-arm vibration syndrome over a career.

Noise: Battery models are dramatically quieter. You can hold a conversation while using one. This matters in residential areas, near schools or hospitals, and for the operator's hearing over years of professional use.

Starting: Battery models start at the press of a trigger. Every time. Instantly. This advantage cannot be overstated — see the next section.

Runtime — the honest limitation: This is where the conversation gets real. A professional battery trimmer or brush cutter working at full output on heavy material typically delivers 15 to 30 minutes of continuous cutting per battery charge. Some manufacturers quote longer runtimes, but these figures often represent light trimming at reduced power settings rather than sustained professional-grade cutting.

For a homeowner clearing their own large garden, 20–30 minutes per battery is manageable — charge one battery while using the other, and rotate. For a professional landscape contractor who needs to work continuously for hours, the maths becomes challenging. Each high-capacity professional battery represents a significant investment, and you may need three or four batteries to sustain a full working day. The batteries alone can cost as much as, or more than, the tool itself.

The practical approach: Many professional users now operate with battery tools for the majority of their work — lawn edging, routine trimming, residential maintenance — and keep a petrol machine for the heaviest clearance work where sustained power over long periods is essential. The two technologies are complementary rather than mutually exclusive.

The Pull-Start Problem: Accessibility and Physical Limitations

Petrol trimmers and brush cutters use a pull-start (recoil start) mechanism. You pull a cord sharply to spin the engine flywheel and initiate combustion. When the engine is cold, this typically involves setting a choke, priming the fuel, and pulling the cord with a sharp, forceful motion — sometimes several times before the engine fires.

This starting method presents a genuine accessibility barrier. People with reduced grip strength, limited hand mobility, shoulder injuries, arthritis, or any condition affecting the hands, wrists, or arms can find it difficult or impossible to generate the force needed to start a petrol engine. The repeated sharp pulling motion can exacerbate existing conditions and is uncomfortable even for fully able-bodied users.

Many experienced professionals and dedicated gardeners have switched to battery-powered equipment specifically because of starting difficulties — not because the petrol tool was inadequate once running, but because they could no longer reliably start it. The push-button start of a battery tool removes this barrier entirely. For anyone with reduced hand strength or mobility, a battery-powered trimmer or brush cutter is not just a convenience — it can be the difference between being able to maintain their garden and not.

Some manufacturers offer "easy start" or "reduced pull" mechanisms on petrol models, and aftermarket electric start adaptors exist for some machines. These help, but they do not eliminate the fundamental physical requirement of the pull-start mechanism.

If you have any doubt about your ability to start a petrol tool reliably, choose battery. The cutting performance of modern professional battery equipment is excellent. The starting convenience is absolute. The only trade-off is runtime per charge — and for most domestic users, even demanding ones, this is manageable with one or two spare batteries.

Multi-Tool (Kombi) Systems

Several manufacturers offer modular systems where a single power unit (engine or battery motor) connects to interchangeable attachments — string trimmer head, brush cutter blade, hedge trimmer, pole saw, cultivator, edger, and more.

Strengths: One power unit, many tools. Saves money compared to buying dedicated tools for each task. Saves storage space. If you invest in a quality power unit, every attachment benefits from that quality.

Limitations: The connection point between power unit and attachment is a potential weak point — flex, vibration, and wear can develop over time. A dedicated tool is typically better balanced and more rigid than a multi-tool equivalent. Switching attachments takes time (though typically only a few minutes).

Best for: Users who need several different tools but do not use any single one intensively enough to justify dedicated machines. Excellent for smaller properties where a trimmer, hedge cutter, and pole saw are all needed occasionally.

Understanding Cutting Heads and Line

The cutting head is where the work happens. Understanding how it feeds line and what line it uses helps you choose a trimmer that works smoothly rather than frustrating you every time the line runs out.

Line Types and Thickness

Trimmer line is available in various diameters and cross-section profiles.

Diameter: Thinner line (1.5–2.0 mm) is standard on domestic trimmers and cuts grass and light weeds effectively. Thicker line (2.4–3.3 mm) is used on professional machines and handles tougher material — thick weeds, nettles, and light woody growth. Some professional users run serrated or reinforced line for extra cutting ability on difficult vegetation.

Cross-section profiles: Round line is the most common and works well for general trimming. Square, star-shaped, and twisted profiles have sharper cutting edges and cut more aggressively, though they also wear faster and produce more noise.

Line feed mechanisms: Bump feed (tap the head on the ground to advance line), automatic feed (the head releases line as it wears), and manual feed (you stop and pull line out by hand). Bump feed is the most common and generally the most reliable.

Metal Blades: When and Why

Metal blades are fitted to brush cutters and some heavy-duty professional trimmers. They are not interchangeable with domestic string trimmers — the tool must be designed and built to accept a blade safely.

Three-tooth and four-tooth blades: For grass, thick weeds, and light scrub. The open blade design throws less debris than a solid disc.

Eight-tooth and multi-tooth blades: For thicker vegetation, brambles, and small woody stems.

Circular saw blades (chisel-tooth): For cutting saplings, dense scrub, and small trees. These are serious cutting tools that demand proper training, a full harness, and comprehensive safety equipment.

Never fit a metal blade to a machine not designed for it. The forces involved are substantial, and the safety features of a brush cutter (guard design, harness attachment, shaft rigidity, gearbox strength) are specifically engineered to handle blade operation safely.

Cutting Swath: Width Matters

The cutting swath is the width of the path the trimmer clears in a single pass. Wider swaths clear more ground per sweep but require more power and make the tool heavier.

25–30 cm (10–12 inches): Typical for domestic cordless trimmers. Adequate for lawn edges and light trimming.

33–38 cm (13–15 inches): Mid-range domestic to light professional. Good all-round width.

38–45 cm (15–18 inches): Professional grade. Efficient for clearing larger areas and heavier growth.

Shaft Design: Straight vs Curved

Straight shafts are longer, provide better reach, and transmit power more efficiently to the cutting head. They are standard on professional equipment and preferred by taller users. Straight shafts are required for metal blade use — curved shafts cannot safely handle the forces.

Curved shafts are lighter, easier to manoeuvre in tight spaces, and often more comfortable for shorter users or for detailed work close to obstacles. They are common on domestic models.

For most homeowners: either works — try both in a shop if possible and see which feels more natural. For professional or heavy-duty use: straight shaft is essential.

Battery Platforms and Ecosystem Thinking

If you already own cordless garden tools, check whether a trimmer is available on the same battery platform before buying a new, incompatible system. The cost saving of sharing batteries and chargers across multiple tools — mower, trimmer, blower, hedge trimmer, chainsaw — is substantial.

The major battery platforms (18V, 36V/40V, 56V, and 80V from various manufacturers) are not cross-compatible between brands. Choosing a platform is a long-term decision — once you have invested in batteries and chargers, switching brands means starting again.

At the professional level, battery cost is the dominant factor. A professional battery can cost as much as a budget domestic trimmer. Building a working set of three or four batteries represents a significant upfront investment — but one that pays back through reduced fuel costs, lower maintenance, and dramatically better working conditions.

Safety Equipment

String trimmers spin nylon line at high speed, throwing grass clippings, stones, soil, and debris in all directions. Metal blade brush cutters are even more hazardous.

Eye protection: Essential for all trimming work. Safety glasses or a full face visor. Stones flung by a trimmer can cause serious eye injuries.

Hearing protection: Recommended for petrol models (which exceed safe noise levels during extended use). Advisable even for battery models during long sessions.

Stout footwear: Closed-toe shoes or boots. Never use a trimmer in sandals or bare feet.

Long trousers: Protect legs from flying debris and from the cutting line itself if it contacts your skin.

For brush cutter use with metal blades: Full face visor, hearing protection, steel-toe boots, long trousers, gloves, and a professional harness with quick-release. This is not optional — it is essential.

Maintenance

Battery models: Very low maintenance. Keep the cutting head clean, replace line as needed, and store batteries at partial charge in a cool, dry location between seasons.

Petrol models: Regular maintenance is essential — air filter cleaning or replacement, spark plug inspection, fuel system care (drain fuel before extended storage or use premixed alkylate fuel), and gearbox lubrication on straight-shaft models. Two-stroke engines require fuel mixed with oil at the manufacturer's specified ratio — incorrect mixing damages the engine.

Line replacement: Learn to reload your cutting head before you need to. Fumbling with line in the middle of a job is the most common complaint about string trimmers. Practice the process at home, not in the garden with gloves on and the sun in your eyes.

Common Mistakes Buyers Make

Buying a Brush Cutter When a Trimmer Will Do

If your work is lawn edges and light weeds, a domestic cordless trimmer is all you need. A brush cutter is heavier, more expensive, and overkill for routine garden maintenance.

Underestimating Professional Battery Cost

The tool itself may be reasonably priced, but the batteries are the real investment. A professional battery trimmer with two or three spare batteries can cost more than an equivalent petrol machine. Factor in the full system cost before deciding.

Buying on Battery Voltage Alone

Higher voltage does not automatically mean better performance. A well-designed 36V brushless trimmer can outperform a poorly designed 56V model. Look at cutting swath, line diameter, build quality, and user feedback rather than just the voltage headline.

Ignoring the Pull-Start Question

If you have any difficulty with grip strength, hand mobility, or shoulder movement, test a petrol pull-start before committing. Better still, choose battery — the starting convenience is worth the trade-off in runtime.

Not Buying Enough Line

Trimmer line is a consumable. It wears, breaks, and needs replacing regularly. Buy a substantial spool when you buy the trimmer — you will go through more than you expect, and running out mid-job means a trip to the shop.

Using a Curved-Shaft Trimmer for Heavy Work

Curved shafts are lighter and manoeuvrable but flex under heavy load and cannot accept metal blades. If you need to tackle anything beyond grass and light weeds, choose a straight-shaft model.

Comparison Table

Pre-Purchase Checklist

• What are you cutting — lawn edges, light weeds, thick weeds, brambles, scrub, or saplings?
• How large is the area you need to trim? This determines whether battery runtime is sufficient or petrol is needed.
• Do you already own cordless garden tools on a battery platform? Compatibility saves money.
• Can you comfortably pull-start a petrol engine? If in doubt, choose battery.
• Do you need a metal blade capability (brush cutter) or is nylon line sufficient (string trimmer)?
• Straight shaft or curved? Straight for heavy work and blade use; curved for light domestic work.
• For professional use: have you budgeted for the full battery system (tool + two or three batteries + charger)?
• Do you need multi-tool versatility? Consider a kombi system if several tools are needed occasionally.
• Have you budgeted for safety equipment — eye protection at minimum, plus hearing protection for petrol?
• Do you have spare trimmer line? Buy with the tool — you will need it sooner than you expect.

Why Buying Through Amazon Makes Sense

Amazon's trimmer selection covers the full spectrum from basic domestic models to professional-grade equipment. Product listings include power source, engine size or voltage, cutting swath, weight, line diameter, and included accessories for direct comparison.

Customer feedback is extremely valuable in this category, where real-world performance over a full season — runtime accuracy, line feed reliability, build quality under sustained use, and starting reliability — reveals far more than manufacturer specifications. For professional equipment, look for reviews from landscape contractors and groundskeepers who describe their workload and the tool's performance over months rather than days.

The accessory ecosystem — trimmer line in various thicknesses and profiles, replacement cutting heads, metal blades, harnesses, and safety equipment — is well represented alongside the primary tools.

Amazon Marketplace Protections

When you purchase through Amazon, several consumer protections apply. Products sold directly by Amazon are covered by standard consumer rights legislation, including the right to return items within a specified period.

For products sold by third-party sellers on the Amazon Marketplace, the A-to-Z Guarantee provides additional protection. If an item does not arrive, arrives damaged, or is materially different from what was described, Amazon will investigate and, where appropriate, issue a refund.

Amazon Renewed products — professionally inspected and restored items — come with their own guarantee, providing confidence when purchasing pre-owned equipment at reduced prices.

Manufacturer warranties apply in addition to Amazon's protections, covering manufacturing defects and premature component failure under normal domestic use.