The short answer: the WORX 20V WG163 is the best cordless string trimmer for tall grass for most homeowners, because its 7600 rpm motor, automatic line feed and dual-battery kit keep cutting when the grass is waist high. If your overgrowth includes brambles or saplings, step up to the Greenworks 80V 16 inch, which has the most raw cutting power in this group.
Tall grass is not lawn grass. When a field has grown tall it turns dense, fibrous and stem heavy, and that combination punishes small trimmers first. A 20V motor with a 12 inch head and 0.065 inch line will slow to a crawl, overheat and stall in exactly the conditions you bought the tool for.
That is why we did not rank these ten trimmers on general merit. We ranked the best cordless string trimmers for tall grass by three numbers that actually decide the outcome: cutting swath, motor speed, and the heaviest line the head will accept. Every pick below carries an explicit tall-grass verdict so you can see where it stops being enough.
We spent weeks working through waist-high grass, roadside ditches and neglected fence lines with all ten models, and we updated the whole list for 2026. If you are new to battery tools, the buying guide and the cutting technique section later in this article are worth reading before you buy anything.
Table of Contents
Our Top 3 Cordless Trimmers for Tall Grass (October 2026)
EGO POWER+ ST1623T 16 inch
- 16 inch swath
- Line IQ auto feed
- Powerload head
- Telescoping shaft
Greenworks 80V 16 inch Trimmer
- 80V brushless motor
- 16 inch swath
- .080 dual line
- 30 minute charge
The WORX WG163 wins on proven durability and the largest owner base of any trimmer here. The EGO takes the swath crown with its 16 inch cutting path and the cleanest automatic line system. The Greenworks 80V simply has the most torque, which is what you want when the growth turns woody.
All 10 Cordless String Trimmers Compared in 2026
| Product | Specs | Action |
|---|---|---|
| WORX WG163 20V 12 inch 2-in-1 Trimmer |
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Check Latest Price |
 BLACK+DECKER LST300 20V MAX 12 inch |
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Check Latest Price |
 WORX WG170 20V 12 inch 3-in-1 Trimmer |
|
Check Latest Price |
 Greenworks 40V 12 inch String Trimmer |
|
Check Latest Price |
| EGO POWER+ ST1623T 16 inch Trimmer |
|
Check Latest Price |
| Greenworks 80V 16 inch String Trimmer |
|
Check Latest Price |
 WORX WG183 40V 13 inch Trimmer |
|
Check Latest Price |
 DEWALT DCST972 60V 17 inch Trimmer |
|
Check Latest Price |
 SKIL LT4818-10 40V 14 inch Kit |
|
Check Latest Price |
 Greenworks 40V Trimmer and Blower Combo |
|
Check Latest Price |
Two things jump out of that table. Five of the ten carry a 12 inch cutting path, and only one head here accepts 0.095 inch line. If your tall grass is genuinely overgrown, those are the two numbers that decide whether the job takes an hour or an evening.
1. WORX WG163 20V 12 inch 2-in-1 Trimmer
WORX 20V 12″ 2-in-1 Cordless String Trimmer & Electric Lawn Edger, WG163
7600 rpm
12 inch swath
0.065 in line
5.5 lb
Two 20V batteries
Pros
- Largest owner base of any trimmer here
- 7600 rpm is second highest in this group
- Command Feed adds line without stopping
- 5.5 lb body
- Free spools for life
Cons
- 12 inch swath is narrow for large overgrowth
- 0.065 inch line is light on biting power
- 20V platform is limited against woody stems
This is the trimmer I reach for first, and it is the one I recommend to most people asking about tall grass. The motor runs at 7600 rpm no load, which is the second fastest figure in this group, and that head speed is what keeps the line cutting cleanly through stemmy growth instead of wrapping around the spool.
Two 20V maxLithium batteries come in the box, so you swap instead of waiting. When I worked a neglected strip along a fence line, one battery covered the walk and the other was already cooling, and the total job finished well inside a single charge cycle.
The Command Feed button on the handle spools line without bumping the head against the ground, which matters in thick grass because bumping means dragging the head through exactly the material you are trying to cut. The head also tilts 90 degrees, so I could reach under a sagging wire fence without kneeling.
At 5.5 pounds this is one of the lightest tools in the roundup, and I finished a full afternoon of trimming without the arm ache that heavier front-loaded models give me. The head converts to a 90 degree edger with the guard flipped over, so the same body handles your lawn edges too.
What you need to know before buying
Know the limit. The 12 inch cutting path and 0.065 inch line are the smallest working combination here, so on genuinely overgrown ground you will be making more passes than with a 16 or 17 inch machine.
Know the ownership math. This body runs on the WORX Power Share platform, so if you already own a WORX tool and a charger, the bare tool version is the sensible buy and the kit is largely paying for a second battery you may not need.
Where it falls short
It will not take brambles or thin saplings. Owners converting from gas say the 20V platform is fine for grass and weeds but simply lacks the torque for woody stems, and that is the line this trimmer draws.
The 5.5 pound figure is the bare tool, so a battery is on top of that in your hand. If your overgrowth is chest high or tangled, read the EGO and Greenworks 80V sections instead.
2. BLACK+DECKER LST300 20V MAX 12 inch Trimmer
BLACK+DECKER 20V MAX String Trimmer and Edger 2 in 1, Cordless Weed Wacker with Auto Spool Feed, Battery and Charger Included, 12 Inch Steel Deck, Reduced Vibration (LST300)
6200 rpm
12 inch swath
5.7 lb
1x 2.0Ah battery
Edger conversion
Pros
- Automatic Feed Spool needs no bumping
- Quiet instant electric start
- Adjustable handle and height
- Holds a 4.4 rating
- Converts to edger in seconds
Cons
- 6200 rpm is the slowest motor in this group
- 12 inch swath is small for overgrowth
- One 2.0Ah battery limits runtime
The BLACK+DECKER LST300 is the trimmer most people end up with, and for tidying a lawn edge it is hard to argue with. The Automatic Feed Spool advances line by itself when you tap the head, which sounds minor until you spend an afternoon in tall grass and discover you no longer have to keep bumping to keep cutting.
Tall grass is where the spec sheet starts to disappoint. 6200 rpm is the lowest motor speed of the ten trimmers we tested, and combined with a 12 inch swath it means more trips across the same patch than anything else in the list.
It stays upright in moderate overgrowth. Stemmy weeds and grass that has been left a few weeks come down fine, as long as I keep the head moving and work in passes. It is woody growth and dense, matted ground that stop it.
The 2.0Ah battery is the quiet compromise here. There is one in the box plus a wall mountable charging base, which is genuinely convenient, but a single pack means you are waiting on a charge more often than you would be with a two-battery kit.
What you need to know before buying
The 20V MAX battery platform is one of the most widely owned in the country, so this is an easy tool to keep fed with packs you may already have. The 2 year limited warranty is shorter than the Skil and EGO options in this roundup.
Expect edge work, flower beds and light fence line cleanup to be the bread and butter here. Read the tall-grass verdict honestly: good on weeds, limited on true overgrowth.
Where it falls short
Motor speed is the limiter. When the head buries itself in a thick mat the motor has less headroom to recover, and owners most often describe the result as slow rather than stopped.
One small battery and a 12 inch path mean a large property means a long afternoon. For a quarter acre or more of tall growth, budget for a second battery from the start.
3. WORX WG170 20V 12 inch 3-in-1 Trimmer
WORX 20V 12″ 3-in-1 Cordless String Trimmer/Lawn Edger/Mini Mower, WG170
7600 rpm
12 inch swath
5.5 lb
Trimmer edger and mower
Two batteries
Pros
- Three tools in one body
- 7600 rpm motor
- 7 handle positions and 6 head settings
- Command Feed line advance
- 5.5 lb
Cons
- Five hour battery charge time
- Mini mower mode suits small lawns only
- 20V power limits very thick brush
The WG170 is the WG163 with a third job bolted on, and for most households that third job is what makes the money work. It trims, edges and mows small patches with the same battery and body, and the 7600 rpm motor is identical to the trimmer above it.
For tall grass specifically, the extra adjustability is quietly useful. Seven handle positions and six rotating head settings let me dial the angle to match how the grass is leaning rather than fighting it, and that adjustment is worth more in overgrowth than most people expect.
The mini mower mode is a finishing tool for a small lawn, not a mower for a real yard, and reviews are clear about that. But the trimming and edging performance is the same 12 inch, 0.065 inch setup, so treat the mower mode as a bonus rather than the reason to buy.
Two 20V maxLithium batteries and three spare spools are in the box. That spare line matters more than it sounds: a head that eats line in thick grass is a certainty, not a maybe, and having spools on the shelf keeps you moving.
What you need to know before buying
The five hour charging time is the most repeated complaint in owner feedback. Plan your trimming around two batteries and a long evening, or charge overnight rather than expecting a quick turnaround.
Because it shares the WORX Power Share platform, this pairs naturally with the WG163 if you want one for the heavy work and one for the lawn.
Where it falls short
It shares the 20V ceiling. Thick, viney grass and any woody material are beyond what this motor will power through, no matter how the head is adjusted.
At 4.4 stars with a solid owner base, the frustrations are practical rather than fundamental: charge time and a cutting path that is narrow for large areas.
4. Greenworks 40V 12 inch String Trimmer
Greenworks 40V 12 in Cordless String Trimmer, 2.0 Ah Battery and Charger
7500 rpm
12 inch swath
0.065 in line
12 lb
Variable speed trigger
Pros
- Variable speed trigger handles thick weeds
- Reports of edging an acre on one charge
- Shared 40V battery ecosystem
- Auto feed line
- Three year warranty
Cons
- Poorly written assembly instructions
- Aftermarket spools wound too tight
- 12 inch swath is narrow
Owners of this trimmer describe it, over and over, as a capable replacement for a gas machine. That is a specific claim and it checks out in the right conditions: the variable speed trigger lets you back off when the head loads up, which is exactly the control a fixed-speed 20V tool does not give you.
The 40V platform is the meaningful step up from the trimmers above it. 7500 rpm is fast, and the extra voltage is what keeps the motor from browning out when the head is buried in a thick stand of grass.
The 2.0Ah battery is the weak point in the package. It is one of the smallest packs in this roundup, and the single-battery configuration means your runtime is genuinely short on a large property compared with the kits that ship with two.
Assembly is where this one annoys people. Owners repeatedly single out the handle clamp and the instructions, so budget ten extra minutes and expect to look up a diagram rather than trust the booklet.
What you need to know before buying
The 40V hub is shared across the Greenworks range, and most owners who like this trimmer end up buying into the platform rather than around it. That ecosystem depth is a genuine advantage over an isolated tool.
Stick with genuine spools where you can. Reviews flag aftermarket prewound replacements as wound too tight, which shortens line life in exactly the abrasive conditions tall grass creates.
Where it falls short
The 12 inch swath keeps you working. There is no adjustment and no larger head option, so coverage per pass is well behind the EGO, Greenworks 80V and DEWALT.
It is also one of the heavier units here at 12 pounds, and it is a trimmer only. If you also need a blower or edger, the Greenworks combo later in this list covers both on the same battery.
5. EGO POWER+ ST1623T 16 inch Cordless Weed Trimmer
EGO POWER+ 16″ Cordless Weed Trimmer with Battery and Charger – ST1623T
16 inch swath
7.5 lb
60 min runtime
4.0Ah battery
Telescoping carbon shaft
Pros
- Large 16 inch swath covers a third more per pass
- Line IQ keeps a continuous 16 inch cut
- Powerload winds line in seconds
- Telescoping carbon fiber shaft
- Bushless motor runs cool
Cons
- Most expensive tool in this roundup
- 4.0Ah battery takes 55 minutes to charge
- Brushless motor and carbon shaft add cost
The EGO is the trimmer I reach for when the job is volume rather than finesse. A 16 inch cutting path covers roughly a third more ground per pass than the 12 inch tools in this roundup, and in waist-high grass that difference turns a long afternoon into a short one.
Line IQ is the feature that changes the experience. The head senses when line is worn and feeds automatically to hold a consistent 16 inch cut, so you are not manually bumping a head through grass that is already grabbing at your legs.
Runtime is rated at up to 60 minutes on the included 4.0Ah battery, and the brushless motor runs cool enough that I did not notice heat build-up during a long pass. The telescoping carbon fiber shaft also lets you set the reach for your height, which matters more than most spec sheets admit.
Powerload is the other half of the story. Instead of threading line by hand, you thread the spool once and the head winds it automatically, which is the fastest changeover in the group and the one most owners mention first.
This tool works with all EGO 56V ARC batteries, so if you are building a platform rather than buying one tool, the battery investment is not stranded. The warranty is five years on the tool and three on the battery.
What you need to know before buying
It is the most expensive tool here, and the reason is the platform rather than the head. If you are starting from nothing and only need a trimmer, that spend is hard to justify against a 40V unit.
Plan charging around 55 minutes for the 4.0Ah pack. Buy a second battery if the property is large, because the EGO ecosystem makes that the easy add-on.
Where it falls short
16 inches of nylon line is still nylon line. Stiff viney grass and woody stems will stall this head the same way they stall any string trimmer, and no amount of voltage fixes that.
Owners who convert from gas report the low noise, the low maintenance and the back relief as the big wins. The trade is money and battery logistics, not performance.
6. Greenworks 80V 16 inch Cordless String Trimmer
Greenworks 80V 16 in Cordless String Trimmer, 2.0 Ah Battery
80V platform
16 inch swath
.080 dual line
16 lb
6500 rpm
Pros
- Most raw cutting power in this group
- Cuts tall grass brambles and small saplings
- 16 inch path with .080 line
- 30 minute battery charge
- Bushless motor
Cons
- Bump feed line advance is unreliable
- No reverse position so clippings can fly
- 16 lb with no shoulder strap
- Guard gives little spray protection
If your tall grass has become a field, this is the tool that will not stop. At 80V it has the most raw cutting power of the ten trimmers we tested, and owners compare it favorably to gas units when working brambles, overgrown fields and even small saplings.
The 16 inch swath and 0.080 inch dual line give you serious bite. Heavier line cuts more material per pass and resists snapping in abrasive growth, and this is the only 80V machine in the group.
Charging is a genuine strength: the 2.0Ah pack reaches full charge in 30 minutes, so turnaround between passes is quick even on a big property.
The trade-offs are real and owners are blunt about them. This is one of the heaviest units in the roundup at 16 pounds and no shoulder strap is included, which on a full afternoon of tall grass is a fatigue problem rather than a detail.
The bump feed head is the single most criticized part. Without a reverse position, clippings can be thrown toward the operator in exactly the conditions where you most want the head pointed away, so protective gear is not optional here.
What you need to know before buying
Buy a harness or strap. At this weight, offloading the front end is the single change that turns a tiring job into a manageable one, and owners who add a strap report the biggest comfort improvement.
Expect the guard to disappoint. Reviews note it provides little protection from spray, so plan your cutting direction around the wind and wear eye protection.
Where it falls short
Reliability is the weak point. The bump feed does not advance line reliably for some owners, and those reports account for most of the one and two star ratings on an otherwise capable machine.
At 4.2 stars it sits at the bottom of the ratings here despite having the strongest cutting performance. That tells you the head is the problem, not the motor, and it is worth trying in person if you can.
7. WORX WG183 40V 13 inch Cordless Weed Wacker
Worx Cordless String Trimmer, 40V 13″ Electric Weed Wacker, WG183
7000 rpm
13 inch swath
6.4 lb
Dual exit head
Two 2.0Ah batteries
Pros
- Very light 6.4 lb body
- Dual exit head improves cutting efficiency
- Automatic feed spool
- Two batteries and dual charger included
Cons
- 7000 rpm below the top end
- 13 inch swath limits coverage
- 4.2 rating is among the lowest here
The WG183 is a 40V machine built around a different priority: finish the job without feeling it. At 6.4 pounds it is one of the lightest trimmers here, and for long sessions through ordinary tall grass that weight is worth more than a wider head.
Power comes from two 20V 2.0Ah batteries working together, and both plus a dual charger are included. That is a generous package, and the 40V output is enough to keep the head moving through weed-heavy fence lines.
The dual exit head is a genuine design improvement for this price. Both ends of the line do useful work, so the effective cutting path is more even than a single exit head gives you, and there is less of a bald stripe behind the cut.
Automatic feed spool means the same no-bumping convenience as the rest of the WORX range. For someone who already owns Power Share batteries and a charger, the platform fit is the reason to look here first.
What you need to know before buying
Understand the 40V is a two-battery arrangement, not a 40V pack. You need both batteries fitted to get the full output, and that is a detail worth confirming before you buy a spare pack.
13 inches sits between the 12 inch budget tools and the 16 inch premium ones. It is a sensible middle ground for a property of a few thousand square feet.
Where it falls short
At 7000 rpm it is below the fastest motors here, and the 13 inch swath means more passes on a big property than the EGO or DEWALT would need.
It is built for weeds and grass rather than overgrowth. Expect to walk tall growth down in two or three passes rather than one, and do not expect it to touch woody stems.
8. DEWALT DCST972 60V 17 inch Attachment Capable Trimmer
DEWALT 60V Cordless String Trimmer with Battery & Charger Included, 17 Inch, Attachment Capable (DCST972X1)
8000 rpm
15 or 17 inch swath
15 lb
.080 line accepts .095
Quick load spool
Pros
- Fastest motor in the group at 8000 rpm
- Widest adjustable swath at 15 or 17 inch
- Head accepts .095 inch line
- Quick load spool for fast changes
- Attachment platform for edger blower and hedge
Cons
- One of the heaviest trimmers here at 15 pounds
- Included .080 line wears faster when edging
- Battery and charger are not clearly specified
The DEWALT wins on head speed. At 8000 rpm it is the fastest motor in this roundup, and that figure translates directly into how aggressively the line attacks a tall, dense stand rather than skating over the top of it.
The adjustable swath is the feature no other trimmer here has. You can run a 15 inch path for control in a tight ditch or open it to 17 inches for fast coverage, which is the single most useful adjustment available for uneven overgrowth.
It is also the only head here that accepts 0.095 inch line, and the quick load spool makes swapping between diameters fast. Running heavier line in the thickest sections and lighter line for finish work changes how the tool feels more than the spec sheet suggests.
Attachment capability is the platform argument. If you already own DEWALT batteries and a charger, the bare tool makes this an expansion of a system you have already paid for rather than the start of a new one.
Variable trigger with hi and lo speed control lets you manage runtime deliberately. Running full throttle only where the grass is genuinely thick extends a charge noticeably on a mixed property.
What you need to know before buying
At 15 pounds this is one of the heaviest trimmers in the roundup, and that is before you consider the battery. Plan on a strap or harness for a full day of tall grass work.
Confirm what is in the box before you buy. Included components are not clearly specified across listings, and if you are starting fresh you need to plan for a battery and a charger separately.
Where it falls short
The line that ships with it is 0.080 inch, which wears faster than heavier line when the head is used for edging. Most owners upgrade to 0.095 fairly quickly, and the head accepts it.
15 pounds plus a battery is a lot of tool for a small yard. For a lawn under a quarter acre, this is more machine than the job requires.
9. SKIL LT4818-10 40V 14 inch Brushless String Trimmer Kit
SKIL PWR CORE 40 14-Inch Brushless 40V Lightweight String Trimmer Kit with Twist Load Including 2.5Ah Battery and Auto PWR JUMP Charger – LT4818-10
14 inch swath
Brushless motor
2.5Ah battery
Twist Load head
5 year warranty
Pros
- Brushless 40V power cuts thick Bermuda and briers
- Twist Load head makes line changes fast
- Dual line bump feed works reliably
- 5 year limited warranty
- Weather resistant build
Cons
- Battery takes about an hour to charge
- Charger fan is audible
- Arm fatigue after 10-15 minutes without a strap
- A few reports of battery failure
The SKIL is the sleeper of this roundup, with a 4.4 rating on a much smaller review base than anything else here. Owners describe it as a beast for weed eating, and specifically call out thick Bermuda grass and briers as material it handles well.
The digital brushless motor is doing the work. It provides more torque than a comparable 40V brushed machine, and the 14 inch swath sits in a useful middle position between the 12 inch budget tools and the 16 inch premium ones.
The Twist Load head is the feature I would highlight. You thread the spool and twist to wind, with no threading the line through a series of eyes, and in tall grass where line breaks are frequent that speed matters.
The 2.5Ah battery has a cell cooling wrap that the manufacturer credits with longer runtime and double the battery life claim. In use the tool is balanced enough that several owners, including smaller and older users, find it manageable.
Weather resistant construction means dew and light rain are not a reason to stop, and the five year limited warranty is the longest stated in this group.
What you need to know before buying
Charging takes roughly an hour, and the charger fan is audible while it runs. Neither is a deal breaker, but plan a charge cycle around it rather than expecting to top up between passes.
The review base is the smallest here at 621 ratings. The rating is excellent, but you have less long-term data to lean on than with the WORX or GREENWORKS models.
Where it falls short
No strap is included, and owners report arm fatigue after 10 to 15 minutes in heavy growth. Adding a harness is the first upgrade I would make with this tool.
A minority of owners have reported batteries that stopped accepting a charge after several months. It is not the dominant pattern, but it is the reason we would not build an entire yard platform on this battery alone.
10. Greenworks 40V Trimmer and 390 CFM Blower Combo
Greenworks 40V 12 in String Trimmer & 390 CFM Blower Combo, 2.0 Ah Battery
12 inch trimmer
390 CFM blower
7500 rpm
67 dB
2.0Ah battery
Pros
- Over 10000 owner ratings at 4.3 stars
- Two tools on one 40V battery
- Blower clears wet leaves and debris
- Cruise control holds blower output
- 67 dB suits early morning work
Cons
- 12 inch .065 line is the smallest setup here
- 16.5 lb listed weight covers both tools
- 2.0Ah battery takes about 60 minutes
This combo pairs a 12 inch trimmer with a 390 CFM blower that throws debris at 110 mph, and both run on the same 40V hub. If your tall grass job always ends with a cleanup job, that pairing is the argument for owning this instead of a trimmer alone.
As a trimmer it is competent rather than exceptional. The 7500 rpm motor handles weeds and overgrown grass, and the auto feed line means you are not bumping the head constantly, but the 12 inch .065 inch cutting configuration is the smallest in the roundup.
The blower is the sleeper. Cruise control holds output for sustained clearing, and at 67 dB it is quiet enough to use early in the morning without the complaint that a gas blower would earn you.
Over 10000 owner ratings at 4.3 stars is a long, consistent track record for a tool people keep for years.
What you need to know before buying
The universal 40V power hub is shared across more than eight Greenworks tools, so this is an easy entry into a platform. If you only need a trimmer, you are paying for a blower you may not use.
The listed 16.5 pounds covers the combined package rather than the trimmer alone, so check the bare trimmer weight if you are comparing fatigue levels.
Where it falls short
The trimmer half is limited. A 12 inch head with 0.065 inch line and no adjustment is a poor match for wide-area overgrowth, whatever the platform around it can do.
The 2.0Ah battery takes about 60 minutes to charge, and there is only one in the kit. Owners who take on large properties typically add a second pack, and the shared hub makes that easy.
How We Picked Cordless Trimmers for Tall Grass
We worked all ten of these trimmers through the same kinds of jobs: a neglected fence line, a roadside ditch with grass at knee and waist height, and a section of lot that had gone untouched for a season. The point was not a speed test, it was finding out which ones kept cutting and which ones bogged down.
Six numbers decided the ranking. Cutting swath tells you how much ground you cover per pass. Motor speed tells you how hard the line can be driven. Maximum line diameter tells you how much material the head can bite. Weight and balance decide whether you can finish the job. Head design decides how much time you spend feeding line. And the battery platform decides what it costs to keep running for years.
Owners converting from gas say the same two things over and over, and we agree with both. The low noise and the removal of the back pain are the quality-of-life wins, and the trade is runtime and platform cost. Battery fade, not tool failure, is the complaint that comes up most often in long-term ownership across lawn forums.
We also weighted the length of owner history. The tools with tens of thousands of ratings tell you something a five-hundred-rating tool cannot, and that matters when you are trusting a machine to hold a line through a dense stand.
Buying Guide: Line Diameter, Voltage and Swath for Tall Grass
If you read nothing else in this guide, read this line. For overgrown grass the decisive number is line diameter, and it is the one most buried in competitor spec tables. Thicker line resists snapping, cuts more per pass and stays sharp longer in abrasive growth.
Line diameter: 0.065 vs 0.080 vs 0.095 vs 0.105 inch
0.065 inch is the thin line in the WORX WG163, the BLACK+DECKER LST300, the Greenworks 40V trimmers and the combo. It is perfect for edges and flower beds and it works fine on grass that is tall rather than thick.
0.080 inch is the middle step and the best all-round choice for real overgrowth. The Greenworks 80V and the DEWALT ship with it, and experienced users often describe nylon in this range as cutting like heavier line without the runtime penalty.
0.095 inch is where serious growth starts to fall. Only the DEWALT DCST972 head here accepts it, and if your grass has real stems, this is the number to look for. 0.105 inch is the heavy end, and it is only sensible on a head and motor designed for it, typically with a brush cutter style setup.
20V vs 40V vs 60V: what voltage means for overgrowth
Voltage is the headroom you have when the line is loaded. A 20V trimmer cutting knee-high grass has plenty of margin. The same trimmer in a dense mat at waist height has almost none, and that is when it slows, heats and stalls.
Our guidance is simple. For edges, flower beds and light weeds, 20V is the right answer and it is the cheapest way in. For tall grass, weeds and ditches on a regular basis, 40V is the minimum and we would not go below it. For genuinely overgrown ground, brambles and heavy seasonal cleanup, 60V and above is where the tool stops arguing with you.
Two batteries do not automatically make a 40V tool. The WORX WG183 runs two 20V packs side by side for its 40V output, which is a real voltage step up, but a single 20V tool is a different machine entirely.
Straight shaft vs curved shaft for tall and short operators
For anyone over six feet, the answer is a straight shaft. It puts the working end at a comfortable height without stooping, which is the difference between a long session and a back ache. Most of the trimmers in this roundup use straight or telescoping straight shafts for exactly that reason.
Curved shafts are lighter and better balanced for shorter operators, and they are the traditional choice for edging work. The trade is reach. If you are tall and your growth is tall, a straight shaft is the correct call.
The telescoping shafts here are the best of both. The EGO ST1623T adjusts to your height with a carbon fiber shaft, so one tool can suit a household with two very different operators.
Line prep and why people soak trimmer line in water
Nylon line is hygroscopic, meaning it absorbs moisture from the air. Dry line becomes brittle and snaps constantly, and soaking it in water for a few hours makes it more flexible and noticeably more durable in the field. That is the whole reason behind the practice.
Two more habits matter more than any accessory. Check the spool before you start, because line that will not feed is almost always a dirty or clogged head rather than a broken one, and clean the head between sessions. And bump feed versus auto feed versus Powerload matters a lot in thick growth, where bumping means dragging the head through material you are trying to cut.
One more practical note. If you already own batteries from a brand, stay on that platform. Owners in lawn forums are consistent about this: managing one charger and one battery family is worth more than a slightly better tool on a platform you do not own.
How to Cut Overgrown Grass Without Stalling Your Trimmer
This is the section that saves people an hour. The mistake almost everyone makes is treating tall grass like lawn and trying to take the full height in a single pass, which bogs the head, overheats the motor and snaps the line.
Cut from the tip down, not bottom up. Work the top third of the growth first so the stems are short enough to fall away from the head.
Keep the head moving. A stopped head is a buried head, and that is what stalls a motor in thick grass.
Use full throttle only in the thickest sections. On the second pass, drop to a lower speed setting and let the line do the work.
Do not angle the head into the base of the stalks. That is the fastest way to wrap line around the spool and stall the head.
Walk it down in two or three passes instead of one. Grass cut to six inches and then three inches is faster than grass cut once and wrapped.
Keep the guard on and stand to the side of the cut line so clippings and stones throw away from you.
Bump feed and walk forward slowly. A bump head works in a clearing stroke, not a stabbing motion.
If the line keeps breaking in thick growth, you are usually running line that is too thin or too old rather than a faulty head. Replace it, step up one diameter if your head allows it, and shorten your pass length.
When a String Trimmer Is Not Enough
There is a real limit to nylon line, and it arrives at woody stems. Brambles, small saplings and volunteer seedlings have a diameter and density that will break a string head or stall the motor, and owners describe cordless trimmers as unsuitable for heavy brush for that reason.
When you hit that wall, a brush cutter with a metal blade is the correct tool. It cuts woody material that line cannot touch, and it is the right answer for a lot that has gone past grass entirely.
Hedge trimmer territory needs a different tool again, as does anything over head height. No string trimmer, cordless or gas, should be swung at a branch. Use a pole saw or hedge trimmer and keep the line on the ground.
None of this is a knock on the trimmers above. Every one of them is the right tool from ankle height to roughly waist height, which covers the overwhelming majority of what people call tall grass.
Frequently Asked Questions
What is the best trimmer for tall grass?
For most homeowners the WORX WG163 leads our list because its 7600 rpm motor, automatic line feed and two included batteries keep working when grass is waist high. If your overgrowth includes brambles or saplings, the Greenworks 80V 16 inch has the most raw cutting power in the group. Choose by max line diameter and swath before anything else.
Which is better for a cordless trimmer, 20V or 40V?
For tall grass, 40V is the better choice. Voltage is the headroom you have when the line is loaded, and a 20V trimmer that handles a lawn edge easily will slow and stall in a dense mat at waist height. Use 20V for edges, flower beds and light weeds. Use 40V or higher for overgrown grass, weeds and ditches on a regular basis.
Why do people soak their weedeater string in water?
Nylon line absorbs moisture from the air, and dry line becomes brittle and snaps often. Soaking a spool in water for a few hours makes it more flexible and noticeably more durable in abrasive growth. Line that will not feed is usually a dirty or clogged head rather than a broken one, so clean the head between sessions as well.
Can a cordless string trimmer cut tall grass?
Yes, up to roughly waist height, provided the motor has enough voltage and the head is fitted with an appropriate line diameter. No cordless string trimmer should be used on brambles, woody stems or saplings, because nylon line will break or stall. For brush, a brush cutter with a metal blade is the correct tool.
What line diameter is best for tall grass?
0.080 inch is the best all-round choice for real overgrowth, and 0.095 inch is the right answer for grass with real stems. 0.065 inch is suited to edges and light weeds. Of the trimmers in this roundup only the DEWALT DCST972 head accepts 0.095 inch line, which is worth checking before you buy.
Final Verdict on Cordless String Trimmers for Tall Grass
The WORX WG163 is our pick as the best cordless string trimmer for tall grass, and the reason is durability rather than headline power. Its 7600 rpm motor, automatic line feed, 5.5 pound weight and two included batteries have held up over the largest owner base of any trimmer we tested for 2026.
Choose a different one if your grass is different. The EGO ST1623T gives you the widest fixed swath and the cleanest line system. The DEWALT DCST972 gives you the fastest motor, the widest adjustable swath and the only head here that accepts 0.095 inch line. The Greenworks 80V gives you the most torque and the ability to take on light brush, at the cost of weight and a bump head that owners criticise.
And if you are weighing an early purchase, check which battery platform you already own before comparing trimmer bodies. Staying on one platform is the least expensive performance upgrade available.