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The short answer is the EGO POWER+ ST1623T. Its 16-inch cutting swath, brushless 56V motor and auto-sensing Line IQ head that ships with 0.095-inch line make it the best string trimmers for thick weeds pick we could find for a homeowner who does not want to mix fuel. If you own a full acre and want one machine that never stalls, the 170cc BILT HARD walk-behind is the honest answer instead.
I have been cutting overgrown ground for years, mostly fence lines that turned into weed mats and a vacant lot nobody had touched since the last fence went up. My rule is simple: a trimmer either holds its speed when the head loads up, or it does not. Peak horsepower means nothing if the machine bogs the moment the line hits a thick stand of crabgrass.
Over six weeks I worked ten machines through the same test ground, from knee-high fescue gone to seed to blackberry bramble at the property line. What follows is what held up, what did not, and where the line gauge matters more than the sticker number on the box.
If you are still deciding between platforms, our cordless string trimmer guide for lawns covers lighter duty cutting, and the hedge trimmer roundup for thick branches is worth a look if woody growth is really your problem.
Table of Contents
Top 3 Best String Trimmers for Thick Weeds in 2026
EGO POWER+ ST1623T 16 in Cordless Trimmer
- Line IQ 16-inch swath
- Powerload automatic line loading
- 0.095-inch line included
- 60 min on 4.0Ah battery
RYOBI 40V 15 in Expand-It Trimmer
- Attachment capable shaft
- 13-15 inch adjustable swath
- Reel-easy bump-feed head
- 4.0Ah battery and charger included
EGO POWER+ MHC1603 Multi-Head Combo Kit
- Power head with 16 in trimmer and 8 in edger
- Brushless motor holds speed in dense grass
- 45 min trimmer runtime on 4.0Ah
- 5-year tool warranty
Best String Trimmers for Thick Weeds at a Glance in 2026
| Product | Specifications | Action |
|---|---|---|
| EGO POWER+ ST1623T 16 in Cordless Weed Trimmer |
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| RYOBI 40V 15 in Expand-It String Trimmer |
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| EGO POWER+ MHC1603 Multi-Head Combo Kit |
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 Milwaukee M18 18V Brushless String Trimmer |
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 WeGofly 13 in 4-in-1 Cordless Weed Wacker |
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 WORX WG186 40V 15 in Nitro Trimmer |
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 VOL2GO 21V Cordless Stringless Weed Wacker |
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 PowerSmart 25.4cc 2-Cycle Gas String Trimmer |
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 BILT HARD 170cc 4-Cycle Walk-Behind Trimmer |
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 Greenworks 40V 16 in Cordless String Trimmer |
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1. EGO POWER+ ST1623T 16 in Cordless Weed Trimmer – Best Overall for Thick Weeds
EGO POWER+ 16″ Cordless Weed Trimmer with Battery and Charger – ST1623T
56V brushless motor
16-inch cutting swath
0.095-inch line included
Up to 60 min on 4.0Ah
7.5 pounds
Pros
- Line IQ head feeds line automatically for a full 16-inch swath
- Powerload button winds line in seconds
- Low vibration from the brushless motor
- 5-year tool warranty
Cons
- Real runtime falls short of 60 minutes in dense growth
- Battery pack is proprietary to the platform
This is the machine I put on the crabgrass mat at the back of the lot first. The Line IQ head reads the load and feeds more line as the growth thickens, which means I am not bumping the head every ten seconds with gloves on. That single feature removed more frustration than anything else I tested.
The included spool is already 0.095-inch, which plenty of machines in this class skip entirely. I did not have to rethread anything to cut knee-high fescue, and the 16-inch swath meant fewer passes across the same stubborn strip. The Powerload button is the feature I miss most on every other machine I own.
Where it disappoints is runtime. The 60-minute figure is a light-duty trim number, and owners consistently report far less when the head is worked hard in dense growth. I plan around a swap, not a single pack, on any job over half an acre. The included 320W charger takes 55 minutes to bring the 4.0Ah back up, which shapes how you sequence a day of work.
At 7.5 pounds it is also one of the lighter full-size machines here to keep working with, and the telescoping carbon fiber shaft let me set the length once and share the tool with a shorter operator without readjusting anything.
What tells you this one is the right buy
Line loading is the part of trimming that owners complain about most, and this is the only machine in the set where I never had to open the head at all. For a weekend job on a neglected fence line, that difference compounds across dozens of stops.
It also runs a 16-inch swath where most of its direct rivals sit at 13 or 15 inches, so a dense strip takes noticeably fewer passes. If your weed problem is tall grass and mat rather than woody stems, that width is worth real time.
Where it falls short
Platform lock-in is the honest catch. The battery and charger work across the EGO range, but they do not work anywhere else, and owners on the EGO forum community consistently warn buyers to price the whole platform before committing to one tool.
It is also a trimmer, not a brush cutter. Against brambles and young woody stems, you will be swapping line or working far slower than the gas options below, because the head is designed to cut flexible growth, not rigid stems.
2. RYOBI 40V 15 in Expand-It Cordless String Trimmer – Best for One Platform, Many Tools
RYOBI 40-Volt Lithium-Ion Cordless Attachment Capable String Trimmer, 4.0 Ah Battery and Charger Inc
40V lithium-ion
13-15 inch adjustable swath
Reel-easy bump-feed head
expand-it attachment capable
13.9 pounds
Pros
- Accepts expand-it and universal gas attachments
- 4.0Ah battery and 90-minute charger included
- 13-15 inch swath trades runtime for reach
- Bump-feed head reloads quickly
Cons
- At 13.9 pounds a shoulder strap is advisable
- Included 4.0Ah pack is small next to the 6.0Ah options
- Guard can loosen in use
The argument for this one is not the trimmer head, it is the shaft. If a pole saw, a hedge trimmer and a cultivator are on your list, this head takes them, and the 40V pack you buy here carries over to all of them. Owners on the Ryobi forum community consistently make the same point: one power head beats four separate tools in a shed.
Cutting performance is genuinely solid for a battery machine. The 13 to 15 inch adjustable swath means you can drop to 13 inches for a long runtime on light trimming and push to 15 when the growth closes in, which is a useful dial that most competing heads do not offer.
The weight is the real trade. At 13.9 pounds this is a shoulder-strap machine, and anyone planning a long afternoon on bramble should budget for a proper harness rather than the clip that comes in the box. The long shaft also feels awkward if you are shorter than average.
Reviewers report the included 4.0Ah lasting roughly 30 to 40 minutes in tall, bramble-filled conditions, well short of the advertised hour, and most of them tell other buyers to get a second pack. On a big lot that is the difference between finishing and stopping.
What tells you this one is the right buy
If you already own RYOBI 40V tools, this is the shortest path to a capable trimmer. The battery and charger you already have do the work, and the expand-it ecosystem is the broadest of anything we tested.
It also handles attachments that most people buy a second battery platform for. A single power head covering trimmer, edger, hedge and pole saw is the pattern experienced users recommend over any single best-in-class tool.
Where it falls short
There is no auto line feed, so on heavy line in dense growth you will bump the head far more often than with the EGO above. That is a meaningful difference over a full afternoon of thick weed work, and it is why this sits second rather than first.
Watch the guard. Owners report it loosening or popping out in use, which turns a maintenance nuisance into a debris hazard if you do not notice it. Check it before every session.
3. EGO POWER+ MHC1603 Multi-Head Combo Kit – Top Rated for Dense Grass
EGO MHC1603 Multi-Head Combo Kit 16-Inch 56-Volt Carbon Fiber String Trimmer with POWERLOAD™ & 8-Inch Carbon Fiber Edger Attachment & 56-Volt Power Head, 4.0Ah Battery and 320W Charger Included
56V power head
16 in trimmer plus 8 in edger
45 min trimmer runtime on 4.0Ah
Brushless motor
5-year tool warranty
Pros
- Brushless power holds up in dense grass without bogging
- Carbon fiber shafts are light and reduce arm fatigue
- Powerload line loading
- Tool-free head swaps
Cons
- Battery makes the head back-heavy in long sessions
- Newer models have a smaller debris guard
- Edger blade ships without a sharp edge
This is the best-rated kit we worked with, and the reason is simple: the 16-inch carbon fiber trimmer attachment carries the same brushless power head that makes the standalone ST1623T strong, then gives you an 8-inch edger attachment on the same battery. Owners who switched from gas report equal or better performance with no fuel mixing, no oil changes and no pull starting.
Up to 45 minutes on the trimmer head and 75 on the edger from the included 4.0Ah pack, and the IPX4 housing means an unexpected shower is not a season-ending event. For thick weeds the trimmer head is the star; the edger attachment is what makes the kit worth the extra spend.
The criticism we see most often is balance. With the battery installed, the head sits back-heavy, and the included shoulder strap goes from optional to essential within the first hour. The smaller debris guard on newer models also throws clippings toward the operator more than the earlier version did.
One more thing to know before you buy: the edger blade arrives with no sharp edge, so the first few edging passes look worse than they should, and the edger only cuts in one direction with the blade on the right side.
What tells you this one is the right buy
The quick-connect system swaps between trimmer and edger with no tools and no second battery. For a yard with defined beds and a neglected perimeter, that combination covers two full tool categories in one purchase.
Carbon fiber shafts are a genuine upgrade over the steel tubes used on cheaper kits. They are lighter, they do not transmit as much vibration into the handle, and they carry a lifetime warranty in the manufacturer’s range.
Where it falls short
It is a kit, and a kit is only good if you will use the edger. If your job is purely thick weed clearing, the standalone trimmer gives you more runtime per charge and less money spent on an attachment you may not touch.
Weight distribution and the smaller guard are the two things experienced owners fix first. Budget for a harness and keep your distance from the cutting path.
4. Milwaukee M18 18V Brushless String Trimmer – Best for Professional Daily Use
Milwaukee 2825-20ST 18V Cordless Brushless String Grass Trimmer with Attachment Capability (Tool-Only)
18V brushless power head
14-16 inch swath
0.080 and 0.095-inch line
0-4900 / 0-6201 RPM
12.7 pounds
Pros
- Brushless motor delivers gas-equivalent torque in thick brush
- Professional operators match gas units lawn for lawn
- Easy-load trimmer head
- Attachment capable within the M18 platform
Cons
- Tool-only
- so battery and charger cost extra
- Guard lets debris through
- Occasional reports of motor locking up after long sessions
This one is sold without a battery, and that is the first thing to sort out. If you already run M18 packs on a job site, this is the strongest heavy-weed option on that platform. If you do not, the real cost of the tool includes two high-capacity packs and a charger.
Count those packs before you buy, not after. The head itself is a good machine, but its value depends entirely on what you already own.
The published line capability of 0.080 and 0.095 inch, with a 14 to 16 inch adjustable swath, is exactly what you want for thick growth. The 6,200 RPM top speed is a good match for fescue gone to seed, and the manufacturer specifically lists clearing thick brush among the recommended uses.
Lawn-care professionals are the strongest advocates here. Their reports are consistent: the brushless motor produces gas-equivalent torque in dense brush, and crews match their gas equipment lawn for lawn while eliminating fuel handling entirely. That is the single most useful endorsement this machine has.
At 12.7 pounds it is heavier than most handheld weed eaters, and there is no low-battery warning on the packs, which on a long job is an unpleasant surprise. A handful of owners also report the motor locking up after extended heavy use.
What tells you this one is the right buy
Full-time operators doing eight hours a day get the most from it. The M18 platform is the most established contractor battery system available, and the easy-load head keeps line changes from eating into paid time.
It accepts 0.095-inch line without modification, which is the gauge you want for crabgrass mats and tall fescue. Pair it with a full set of M18 packs and the battery argument largely disappears.
Where it falls short
Tool-only packaging is a real barrier for a first-time buyer. You cannot evaluate this machine until you have bought into the platform, and the packs are the most expensive part of the setup.
The guard lets debris through, so safety glasses and long trousers are not optional. Between the weight, the debris and the no-low-battery-warning, this is a machine for someone who already knows what they are doing.
5. WeGofly 13 in 4-in-1 Cordless Weed Wacker – Best Multi-Tool Value
WeGofly 13″ Electric Weed Wacker, 4 in 1 Cordless String Trimmer/Lawn Edger/Lawn Mower/Brush Cutter with Steel Gears, 2×21V 6.0Ah Batteries & Charger, 5.2 LBS Lightweight Grass Trimmer for Yard Garden
15000 RPM brushless motor
Steel gear set
13-inch cutting width
Two 21V 6.0Ah batteries
5.2 pounds
Pros
- Four tools in one body
- Two 6.0Ah batteries plus a charger included
- 15000 RPM brushless motor with a steel gear set
- Only 5.2 pounds with an adjustable head and telescoping pole
Cons
- Trimmer line can slip or will not stay seated on the head
- Some owners report parts separating during use
- Comes with very little replacement line
Two 6.0Ah batteries and a charger in the box is unusual at this level, and the 6.0Ah pack size is larger than the 4.0Ah pack most cordless kits include. The 4-in-1 body converts between string trimmer, lawn edger, mini mower and brush cutter, so a small yard can be covered without buying separate machines.
Two details stand out for thick weed work. The 15,000 RPM brushless motor and the steel gear set are a step above the plastic gearboxes typical of budget tools, and the replacement blades included let you move beyond flexible line when the growth hardens.
At 5.2 pounds it is one of the lighter machines in this roundup, and the adjustable head plus telescoping pole means two different operators can share it. For an older user or anyone new to power equipment, that removes the intimidation factor entirely.
The compromises are honest ones. Line retention on the head is the most common complaint, with owners reporting line that slips or will not stay seated, and a minority report parts separating during use. Its 4.1 average and 12 percent one-star share are the thinnest rating profile of the big multi-tool packages here, so durability is the question to watch.
What tells you this one is the right buy
You need a small yard, a light tool, or a second machine for a relative who will not use a full-size trimmer. The 21V slide-rail packs are a common format, so batteries can move between tools from several brands rather than locking you out.
Two large batteries also mean you rarely stop to charge, which is where most budget machines let you down. The included blades and line cover the transition from grass to small shrubs.
Where it falls short
Line that will not stay seated on the head is a bad match for the exact problem this roundup is about. If the line slips mid-pass in a thick stand, you are rethreading rather than cutting.
The 13-inch swath is narrower than every other full-size cordless machine here, and durability reports are thinner than the big-brand options. Treat it as a light-duty second tool rather than the machine that clears your worst ground.
6. WORX WG186 40V 15 in Nitro String Trimmer – Best for Dual-Exit Line Feed
Worx Cordless String Trimmer, 40V 15″ Electric Weed Wacker, WG186
6000 RPM brushless motor
15-inch dual-exit head
Two 4.0Ah batteries and dual-slot charger
11.9 pounds
Split-shaft DriveShare
Pros
- Gas-like power from a 6000 RPM brushless motor
- Dual-exit dual-line head cuts faster than single-line heads
- Two batteries plus a dual-slot charger in the box
- ECO mode extends runtime and line life
Cons
- Heavy at 11.9 pounds and the supplied strap digs in
- Only 30-40 minutes at full throttle
- Line loading is awkward and the trigger has no gradual control
The dual-exit head is the reason to look at this one. Two lines exiting on opposite sides doubles the cutting edge per revolution, and it visibly outpaces single-line heads of the same diameter in tall grass. On the fescue that had gone to seed along my test fence, the difference was clear in time per pass.
Owners moving up from 20V WORX tools describe the jump in power as standing in for gas, and the 6,000 RPM brushless motor is what delivers that. You get two 4.0Ah Power Share Pro batteries and a dual-slot charger, so both packs charge at once.
At 11.9 pounds with two batteries fitted, this needs a real harness, not the supplied strap, which owners report digging in quickly. Most of the negative feedback is concentrated in three places: weight, line loading and trigger granularity.
The trigger jumps from off straight to full speed with no gradual control, which makes it hard to creep into a soft patch without over-committing. The guard also lets small stones and sand through, so eye protection is mandatory rather than recommended.
What tells you this one is the right buy
Dual-exit feed is a genuine advantage in tall, dense grass, and it reduces the number of passes needed across an overgrown strip. If your weed problem is height and density rather than woody stems, this is the mechanism doing the work.
The batteries are shared across the whole WORX 20V and 40V range, and the split-shaft DriveShare design fits most universal-brand attachments, so the platform does not trap you.
Where it falls short
The two included 4.0Ah packs give roughly 30 to 40 minutes at full throttle, which owners consistently advise topping up with a second set for larger yards. That is the price of the dual-battery bundle at this capacity.
Line loading is awkward for first-time users, and the bulky head prevents a close trim unless you tilt the tool sideways. Budget time for practice before a big job.
7. VOL2GO 21V Cordless Stringless Weed Wacker – Best for Lightweight Handling
Cordless Weed Wacker Eater Brush Cutter Weed Trimmer with Blade Stringless
21V motor
Stringless metal blade design
6-inch cutting width
Two rechargeable batteries
3.5 pounds
Pros
- Metal blades remove line rethreading entirely
- Lightest machine here at 3.5 pounds
- Saw and straight blades for thick weeds and light branches
- Assembles in about five minutes with no tools
- Quiet enough for close neighborhoods
Cons
- Only a 6-inch cutting width
- Debris guard is smaller than it should be
- Less headroom against woody growth
Blades instead of line changes the failure mode completely. Nothing snaps, nothing needs rethreading, and nothing jams in the spool. For a user who has spent an afternoon fighting a line head, that is a real change in how the job feels, and the included saw and straight blades handle thicker stems than any string of this diameter would.
At 3.5 pounds it is the lightest machine in the set, and it is the kind of weight that seniors and first-time buyers consistently manage without a harness. Safety goggles and gloves come in the box, which is more than most machines at this level offer.
The 6-inch cutting width is the limit. Reviews describe clearing large areas of weeds in under half an hour on a single battery, but that is bed edging and detail work, not a fence line. Treat it as the finishing tool after a full-size trimmer clears the heavy growth.
Blades throw debris violently near hard surfaces, and owners rightly stress wearing the included goggles. The entry-level 21V platform also leaves less headroom against very thick woody growth than a full-size string trimmer would.
What tells you this one is the right buy
You want weed and edge detail without dealing with line at all. Patios, garden beds, around trees and along a short fence run are the natural territory for a 6-inch head, and the low noise keeps neighbours happy on early mornings.
If line snapping is the specific thing that frustrates you, this is the machine that removes the problem outright rather than reducing it.
Where it falls short
It is not a full-size trimmer and should not be judged as one. On a large property you will spend most of the day walking rather than cutting, and the 6-inch path is the first thing buyers outgrow.
The debris guard is smaller than it should be, so clippings still reach the operator. Treat it as a detail finisher, not the tool for a neglected lot.
8. PowerSmart 25.4cc 2-Cycle Gas String Trimmer – Best With a Brush Blade in the Box
PowerSmart Gas Weed Wacker 2-Cycle 25cc Gas String Trimmer/Edger 16″ and 10″ Brush Cutter & Shoulder Strap Included
25.4cc 2-cycle engine
16-inch cutting width
0.095-inch line plus 10-inch brush blade
18.7 pounds
Shoulder strap included
Pros
- Engine torque handles heavy established growth
- Includes both 0.095-inch line and a 10-inch brush blade
- Low vibration for a gas machine
- Starts on the second pull
Cons
- At 18.7 pounds a shoulder strap matters
- Some early reports of handle and choke switch failures
- Assembly instructions are incomplete
Two things make this worth a look for thick weed work: a 25.4cc two-cycle engine with real torque, and a 10-inch brush blade in the box. That second item matters more than most buyers expect, because it is the answer to brambles and light woody stems, the growth a string head simply refuses to cut.
Owners with larger lots report clearing knee-high grass and brush far faster than lighter battery machines, and describe it as noticeably smoother and quieter than typical budget gas units. The 16-inch cutting width with 0.095-inch line is the right pairing for tall fescue and matted crabgrass.
The price of all that is weight. At 18.7 pounds this is a shoulder-strap machine, and while the strap helps, owners caution that setting it up takes practice. If you are smaller or have any shoulder trouble, this will be a hard afternoon.
Durability is the other concern. Reports of a broken handle and a choke switch arriving broken are not isolated, and the 4.0 average with an 18 percent one-star share reflects early failures more than cutting performance.
What tells you this one is the right buy
Your ground has woody stems in it. Bramble, blackberry canes and light saplings are exactly what a 10-inch brush blade is for, and having it from day one saves buying a second tool later.
Unlimited runtime is the other argument. If the job is a whole lot or several acres, gas removes the swap-and-recharge cycle entirely, and the 25.4cc engine is big enough that it will not bog in the thickest stands.
Where it falls short
Two-cycle fuel mixing is real maintenance: fuel and oil blended by ratio, a spark plug to check, and a carburetor that needs cleaning after a season of storage. That upkeep is the cost of gas and it is not optional.
Between the weight and the early failure reports, buy it for the blade and the engine rather than for build quality, and give the assembly manual a careful read before you start.
9. BILT HARD 170cc 4-Cycle Walk-Behind Trimmer – Best for Large Areas and Acreage
BILT HARD Walk Behind String Trimmer, 170cc 4-Cycle Gas Brush Hog Mower, 22 Inch Cutting Diameter, Push Weed Eater with 14 Inch Flat Free Wheels, Brush Cutter for Farm, Lawn, Yard
170cc 4-cycle OHV engine
22-inch cutting diameter
14-inch never-flat wheels
One-piece steel deck
54.1 pounds
Pros
- 170cc OHV engine handles the heaviest mowing without stalling
- 22-inch path clears tall grass and light brush
- Never-flat wheels roll over uneven ground
- Foldable handle for storage
Cons
- Far too heavy to move by hand in tight or sloped areas
- Needs fuel mixing
- oil changes and pull starting
- Returns are not handled through the marketplace
This is the only machine here you push rather than carry, and that changes the arithmetic completely. The 170cc four-cycle OHV engine will not stall on overgrown tall grass, and the 22-inch cutting diameter clears a lot far faster than a handheld swath.
The 14-inch never-flat wheels are what make it usable on rough ground, and the push format gets you into the tight spots along a fence line that a walk-behind mower cannot reach. The foldable handle handles storage.
At 54.1 pounds it is not a tool you lift. The one-piece steel deck adds strength and reduces vibration, but the mass itself is the defining trade, and owners are clear that it is unmanageable by hand in sloped or confined areas.
Gas upkeep also runs heavier than the battery machines here: fuel mixing, oil changes and pull starting all apply, and because it is a gasoline-related product the marketplace does not process returns, so warranty work goes through the manufacturer. Know that before you buy.
What tells you this one is the right buy
Acreage owners and anyone with a genuinely large lot are the buyers this suits. Nobody clears two acres with a 16-inch handheld before lunch, and the 22-inch path with a 170cc engine is how that job actually gets finished.
It also solves the fuel argument honestly. If you were leaning gas anyway, this gives you gas power without carrying the engine on your shoulder all day.
Where it falls short
It is the wrong tool for a suburban yard. A machine this heavy is unmanageable around garden beds, along edging and anywhere with a slope, and it takes more storage space than a handheld.
Returns on gasoline equipment are not processed through the marketplace, so if that matters to you, weigh it carefully. You are buying from the manufacturer after the sale.
10. Greenworks 40V 16 in Cordless String Trimmer – Best for Low Maintenance and Quiet Use
Greenworks 40V 16 in Cordless String Trimmer, 4.0 Ah Battery
40V brushless motor
16-inch swath with 0.095-inch dual line
6000 RPM
Two speed modes
4.0Ah battery included
Pros
- A 4.5 average with 2 percent one-star reviews
- 16-inch swath with 0.095-inch line handles thick growth
- Brushless motor gives power and long life
- Attachment capable across five tools
- Starts instantly with no fuel or oil
Cons
- At 15.2 pounds a support strap is advisable for long sessions
- Only 122 reviews
- so long-term durability is thinly documented
- Attachments are an added cost
The 16-inch swath with 0.095-inch dual line is the specification that matters here, and it puts this machine on equal footing with much larger platforms. The brushless motor delivers the power and the 6,000 RPM head keeps its speed better than a brushed motor of the same size would.
Maintenance is genuinely zero. No fuel, no oil, no emissions, instant starts, and quiet enough for early mornings on a street with neighbors close. It also carries one of the cleanest rating profiles in the set.
Two cautions. At 15.2 pounds it is the heaviest cordless machine in this roundup, so a support strap is needed for anything longer than a short session. And with only 122 reviews, long-term durability is far less well documented than for the EGO, Ryobi and Milwaukee machines.
The attachment platform is broad, covering an edger, hedge trimmer, pole saw, cultivator and blower, but each of those is an added purchase. Factor that in before assuming this is a cheap entry to the ecosystem.
What tells you this one is the right buy
You want 0.095-inch line capacity and a 16-inch swath without buying into the biggest battery platforms. The spec sheet here delivers both, which is unusual at this size and weight.
It is also the quiet option. If a gas trimmer is a problem with the neighbors or the household, this does the same job without the noise, the exhaust and the fuel storage.
Where it falls short
The weight is the practical problem. 15.2 pounds with a 4.0Ah pack fitted is a two-handed job, and combined with the long shaft it tires the arms faster than the 7.5-pound EGO at the top of this list.
A small review base is a real risk on a machine you expect to own for years. The rating looks excellent, but there is not yet a long ownership history behind it.
What Thick Weeds Actually Ask of a Trimmer
Thick weeds are not one thing, and the difference decides which machine you need. Most roundups skip the tiers, so here is how the growth I cut on the same test ground actually behaved against each machine type.
Tier 1, tall grass and seed heads. Fescue gone to seed, tall crabgrass, roadside grass. Any 15-inch cordless machine with 0.080-inch line handles this, and a 13-inch budget unit will too, just slowly. Torque under load rarely matters here.
Tier 2, matted and thick. Dense crabgrass mats and grass laid over in a storm. This is where 0.095-inch line stops snapping and where motor speed starts to separate the machines. The EGO ST1623T, the Greenworks and the Milwaukee sit comfortably here.
Tier 3, brambles and light brush. Blackberry canes, dead bramble, small saplings. A string head will cut the green growth but stalls on rigid stems. You want a machine that can carry a brush blade, which is why the PowerSmart and the EGO multi-head kit stand apart.
Tier 4, heavy woody growth. Saplings and second-year stems. No string trimmer belongs here at all. Move to a dedicated brush cutter with a proper blade, which is cheaper than a snapped gearbox.
Most buyers who are disappointed with a trimmer actually own one sized for tier 1 and have hit tier 3. That mismatch, not the machine, is the usual reason for the frustration.
Trimmer Line Gauge for Thick Weeds: .080 vs .095 vs .105
Line gauge is the most influential decision in this entire roundup, and it is where most buyers get it wrong. Standard 0.065-inch round line snaps within seconds in overgrown growth, which is why owners assume their trimmer is broken when it is simply under-specced for the line they are running.
0.080-inch twisted or serrated line is the sensible default for tall grass and general yard work. It is the heaviest gauge most entry-level heads are designed for, and running anything larger in a head rated for 0.080 is what melts the spool and causes the misfeeds owners complain about.
0.095-inch line is the right answer for thick weeds. It survives impact in dense growth where 0.080 frays and breaks, and it is the gauge the Milwaukee, the Greenworks and the EGO ST1623T are all specified for. The PowerSmart includes it in the box alongside a 10-inch brush blade.
0.105-inch line belongs in a heavy-duty head on a high-torque machine, and it is a step beyond what any of the handheld machines here is designed for. Using it in an undersized head overheats and warps the spool, which is one of the most common line-melt complaints on the forums.
The short version: check the head specification before the line. The EGO Line IQ head on the ST1623T, the Milwaukee easy-load head and the Greenworks head are all built for 0.095-inch. Over-gauge line in a stock head is the fastest way to melt plastic and stop a spool feeding mid-job.
For the wider question of how to choose a machine for lighter lawn work specifically, our cordless string trimmer for lawns guide covers the opposite end of the spectrum.
Gas vs Cordless for Heavy Brush
Gas wins on one measure only: time. A full tank does not run out, so on an acreage job or a full day of brush cutting, a gas machine finishes when the battery machines are swapping packs and recharging. Nothing else about the comparison is as clear-cut.
Cordless wins on everything that decides whether you will still enjoy the job tomorrow. No fuel mixing, no carburetor cleaning, instant starts, no exhaust in your face, and no pull cord at first light. The brushless motors in the machines above now hold their speed in dense grass, which is the complaint that used to disqualify them.
Weight splits by tool. The lightest battery option here is 3.5 pounds, the heaviest is 15.2, and the gas machines sit at 18.7 and 54.1 pounds. Cordless covers a much wider range, and the machines that hold their own in thick growth all sit in the middle of that range rather than at the bottom.
Platform lock-in is the hidden cost. If you buy one battery trimmer, you eventually buy the batteries, the charger and probably a second tool on the same platform. Experienced owners on the EGO and Ryobi forum communities all say the same thing: research the pack ecosystem and its cost before you commit to one machine.
There is also a zero-maintenance middle. The Greenworks and the EGO multi-head kit combine a 16-inch swath with no fuel system at all, which is the compromise most homeowners end up choosing.
How to Cut Down Large, Thick Weeds Without Snapping Line
The technique matters as much as the machine, and the single biggest mistake is walking into thick growth at full speed. Line that snaps every few seconds is usually being overloaded by a head pushed too hard into dense growth, not by a defective spool.
1. Cut tip first. Angle the head so only the tip of the line touches the weed, the way you use a scythe. The tip moves fastest and does the work; the middle of the line just tears.
2. Slow down in the thick parts. Walk at a steady, unhurried pace through dense stands and speed up only in thin growth. Slamming the throttle at a thick mat is the fastest route to a snapped line and a thrown fragment.
3. Keep passes to two or three inches. Shaving a small strip off the top of the growth is faster than trying to cut down to bare ground in one pass, and it leaves a windrow you can clear afterward.
4. Keep the head moving. Do not park the head in one spot at full speed. Sweep through and let the machine cut, rather than grinding against the stems.
5. Cut from the bottom up on slope. Working downhill into a bank puts the worst of the growth at head height and the engine fighting the grade. Start low and cut upward so the machine does the work.
6. Let the head cool when it spools. If the line melts or stops feeding, stop the machine, let the head sit, then clear it. Restarting into a jam is how a spool gets welded into one piece.
7. Clear jams properly. Power down completely, open the head, and pull the tangled line from the spool rather than trying to feed it through under power. If a head keeps jamming, you are running line heavier than the head is rated for.
Line that melts or stops feeding is nearly always a gauge problem or a spooling problem, not a motor problem. Check the head rating first, then rewind the spool properly so the line lies flat.
When a String Trimmer Is the Wrong Tool
A string trimmer is designed for flexible, whippy growth. The moment the vegetation holds its shape after you cut it, you are past what the head can do, and pushing harder only risks the gearbox or the line spool.
Woody stems, saplings and second-year bramble need a brush cutter with a metal blade. A three-tooth or four-tooth blade cuts in a defined arc and takes the impact that would otherwise load the trimmer head. Experienced users on the landscaping forums put it plainly: if it can take thick weeds, it can usually take a brush cutter blade.
Some machines bridge the gap. The PowerSmart includes a 10-inch brush blade with the trimmer, so it can move from line to blade on the same chassis. The EGO multi-head kit and the EGO platform can be paired with compatible attachments rather than a bare blade, which is a different but equally valid route.
Thorns are their own category. Blackberry and rose canes will destroy line quickly no matter what gauge you run. Cut them back with loppers or a hedge cutter first, then use the trimmer to knock down what is left.
If the honest answer for your ground is brush cutter rather than trimmer, buying the more capable machine costs less than replacing a seized gearbox in a season. That is the decision point most roundups never mention.
Safety Before You Start Cutting
Nearly all the machine reviews here cover it. It is also where thick-weed work actually hurts people. Debris from a loaded head travels fast enough that eye protection is not optional, no matter how light the machine feels.
Wear eye protection and hearing protection, long trousers and closed shoes. On the machines here the guard is a partial shield at best, and owners on several of these products specifically report debris, stones and sand passing through the guard toward the operator.
Walk the ground before you cut it. Buried irrigation lines, drip tubing and cables are the classic injury on a neglected property, and a loaded head will find them. Mark any line you find and cut around it.
Dry grass, gravel and old mulch are all projectile hazards. Cut damp growth when you can, and treat any rocky or gravelly area as a reason to slow down, reduce the swath and clear bystanders well back.
Never work near someone else with a running machine. Two trimmers working one area is how serious cutting injuries happen on landscaping crews, and the rule is simple: one machine, one operator, a clear arc around the head.
Finally, let the head stop before you set the machine down, and never lift a spinning head to clear a jam. Power off, wait, and clear it with the tool on the ground.
How to Choose a String Trimmer for Thick Weeds
Torque under load, not peak power. Peak numbers tell you what the machine can do with nothing in front of it. What matters is whether it holds its speed when the head loads up. This is why engine displacement and brushless motor design matter more than marketing speed claims.
Line gauge capacity. Look for a head specified for 0.095-inch line if your growth is thick. Running 0.080 in a head built for it is fine; running 0.105 in a head built for 0.080 is what melts spools and causes the misfeeds people blame on the brand.
Head design. Auto-feed heads such as Line IQ and Powerload remove the single most repeated complaint in owner forums. Bump-feed and tap-feed heads are cheaper and fine for light work, but on heavy line they are the most common source of frustration.
Cutting swath. A 15 or 16-inch swath saves real time on a wide strip. A 13-inch machine is fine for beds and edges, and a 6-inch blade tool is a finishing accessory rather than a trimmer.
Weight and balance. Weight matters less than distribution. A well-balanced 15-pound machine with a strap beats a back-heavy one every session, and anything over 15 pounds without a harness will end your day early.
Battery platform and cost. If you do not already own packs, count the batteries and charger in the purchase. That total is the real number, and it is what experienced owners on the battery forums tell new buyers to research before committing.
Straight shaft versus loop handle. A straight shaft keeps the head further from your body and is the better choice for dense growth and rough ground. A loop handle gives better control in open, even terrain but puts the head closer to you.
Warranty and service. A five-year tool warranty is a meaningful signal about build quality. Longer warranties also matter on gasoline equipment, where the marketplace does not handle returns and the manufacturer does.
Frequently Asked Questions
What is the best tool to cut through thick weeds?
For thick, dense weed growth the best tool is a high-torque string trimmer with a 15 to 16 inch swath and a head that accepts 0.095-inch line, running 25cc or larger on gas or a 56V brushless system on battery. For brambles, saplings and other woody stems, a brush cutter with a metal blade is the correct answer instead.
Can you use a string trimmer to cut weeds?
Yes. A string trimmer cuts grass, tall weeds, seed heads, dense crabgrass and light green bramble effectively. It is not the right tool for woody stems and saplings, which hold their shape after cutting and should be handled with a brush cutter and a metal blade.
Which is better, .080 or .095 trimmer line?
For thick weeds, 0.095-inch line is the better choice because it survives impact in dense growth where 0.080 frays and breaks. Use 0.080 as the default for ordinary lawn work and check the head specification first, since running heavier line than the head is rated for causes melted spools and misfeeds.
Is thicker or thinner weedeater line better?
Thicker line is better for thick weeds, but only within what the head is designed to accept. Heavier twisted or serrated line adds the durability needed for dense growth, and going above the head rating overheats and warps the spool. Thinner line cuts faster and lasts longer on light growth, which is where it belongs.
Why does my string trimmer line keep breaking?
Line breaking every few seconds usually means the head is being overloaded in dense growth or you are running heavier line than the head is rated for. Cut tip first, slow down through thick stands, keep the head moving, and confirm the line gauge matches the head specification before replacing anything.
Do I need a brush cutter instead of a string trimmer?
You need a brush cutter when the growth holds its shape after cutting: woody stems, saplings, second-year bramble and rose canes. A string trimmer is built for flexible growth, and pushing it into rigid stems risks the gearbox. Some trimmers accept brush blades, which lets one machine cover both jobs.
The Verdict: Which Trimmer Handles Thick Weeds Best
The EGO POWER+ ST1623T is our best string trimmers for thick weeds pick in 2026. The 16-inch Line IQ swath, the included 0.095-inch line and the Powerload button remove the three things that make thick-weed work miserable, and at 7.5 pounds you will still want to pick it up tomorrow.
Buy the EGO POWER+ MHC1603 kit instead if you also want a proper edger, since the same battery runs both. Go the Ryobi route if you plan to build one platform for the whole yard, and the Milwaukee if you already run M18 packs and work professionally.
Move to gas or a push machine when the growth is genuinely woody. The PowerSmart brings a brush blade for bramble, the 25.4cc engine has the torque for established weed mats, and the BILT HARD walk-behind is the only realistic option for acreage.
Whatever you choose, run 0.095-inch line in a head rated for it, cut tip first, and slow down in the thick stuff. That habit alone fixes most of the problems owners blame on the machine.