Don’t call it a weed whacker, weedwacker, or weed eater. But you do need one.
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A string trimmer is the indespensible power tool that puts the finishing touches on a yard by shaving off grass that a lawn mower can’t reach. Some people mow then trim, others trim then mow (particularly those who bag the clippings). Either way, the results should be a neat landscape. But trimmers do more than neaten up. They can cut down tall grass and weeds to keep border areas under control, either prior to mowing or as an alternative to mowing. With a deft hand they can be turned sideways to cut a notch along sidewalks, patios and drives. The notch keeps grass and weeds from growing over the pavement’s edge. You’ll be glad of this come winter because pavement with a neat edge is easier to clear of snow compared to one that is overgrown. Equipped with an Aero-Flex trimmer attachment, a string trimmer can function as a mini mower for cutting grass and weeds in difficult areas such as on steep banks and ditches.
Read on for quick info on the best string trimmers from our testing, then scroll down for buying advice and in-depth reviews.
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This Stihl operates at an almost monotone rpm. All you have to do is move along, relentlessly and explosively cutting just about anything that stands in your path. For all its power, it has slightly better vibration damping than the Echo below and is a bit heavier. The FS 91 R is a highly developed product for professionals—but even if you’re not, you could still avail yourself of it if you have a large property. Set its rotary-dial choke and pull the recoil start. It may start, in which case you press the throttle lever and the choke dial automatically moves to the run position. If it doesn’t start on a couple of pulls, move the dial to the semi-choke position and pull again.
A string trimmer spins a line head by means of either a gas engine (in almost all cases burning a gas-oil fuel mixture) or it uses a lithium-ion battery and a DC motor. The harder you work the string trimmer, the tougher the machine you need to buy. Trimming a large and diverse rural property requires a far more robust power tool than if you live on a 1⁄4-acre lot.
Many people are looking to cordless string trimmers powered by a lithium-ion battery to meet their needs, especially in suburbia. Although cordless string trimmers still lack the raw weed-slashing power of professional-grade gas-engine machines, they have narrowed the performance difference. A benefit that a battery-powered trimmer provides that a gas trimmer can’t touch is that it’s quiet. If noise reduction is important to you, a cordless string trimmer is your obvious choice.
The gas-engine machines here are pro-duty and take a 50:1 gas-oil fuel mix. If you need weed-trimming power above all else, they will provide it, particularly if you equip the trimmer with a heavy-duty line. Also, if your needs are closer to the heavy-duty end of the work spectrum, buy a machine that powers the line head with a solid steel drive shaft and not a cable. These trimmers are heavier and more expensive than cable-driven trimmers, but they will stand up better to cutting heavy weeds and light brush.
Whether it’s powered by a gas engine or a battery and brushless motor, every machine here gave a good account of itself in our testing. Scroll through our reviews to see the machines that withstood our rigorous test.
We used the trimmers to cut down knee-deep weeds and wild flowers.
We test our gas-engine and battery-powered string trimmers in identical fashion. We use the machines on ordinary suburban lawn grasses such as blue grass, perennial ryegrass, and fescues in a variety of suburban and rural locations. However, our most severe testing occurred along the sloping bank of a sand floor drainage basin in southern New Jersey, where we use the trimmers to cut down knee-deep weeds and wild flowers. We also did considerable edging where sidewalks meet lawns.
For battery-powered trimmers, our primary goal was to assess power and run time. For gas-engine trimmers, we wanted to judge whether the power they provided was offset by their noise and weight. For all trimmers, we wanted to see if each machine was comfortable and well balanced, and whether its line feed was finicky or robust. We found that especially when we were using the machines to cut down weeds, the growth was so tough, it took an immediate toll on the trimmer’s line, causing us to use the bump feed line mechanism at twice or three times the rate that we would in normal grass trimming.
We reserved some of the toughest test material for this string trimmer. You might think that unfair. We don’t. Having years of experience behind this company’s string trimmers, we were confident this cordless 56-volt trimmer could handle the work. It did. We fogged our coveralls with bug spray to keep the ticks off, snapped the 2.5-Ah battery into the Echo and waded in, felling grass, weeds, and briers both to clear the area and to make access for chainsaw testing. The Echo performed beautifully, its robust head is a reliable line feeder.
When trimming around the base of trees and doing work that was less severe, we set the trimmer’s two-speed selector switch from high to low. This lower speed not only conserves battery life but makes the machine far easier to handle when edging or to reduce the likelihood of accidentally damaging a fence post or, more importantly, a nearby plant.
The Echo's debris shield is narrow, to fit into tight spots, but it's thick and solid. Its line head is also robust and a reliable line feeder.
We attached a string trimmer accessory to DeWalt’s massive 60-volt power head and waded into a drainage basin to face off with some tall stuff, slicing down weeds, grass and light to medium briars as we went. If it wasn’t such hard work, it was almost fun. The DeWalt more than proved its capability in that jungle, then we slipped into its low (rpm) setting, tipped it vertically and cut a nice, neat channel at the edge of a sidewalk and along some curb. This is a substantial machine, weighing 13.4 pounds. But its balance is good and we didn’t find it tiring to use. Nor did we find problems with the string trimmer head that were referenced online. What we did find is a rock solid trimmer capable of taking a pounding while delivering a clean cut.
In contrast to the Echo's debris shield, DeWalt's shield is wide and deep. Its line head is also a reliable line feeder and the DeWalt's braided line was effective at slashing grass and fibrous weeds.
This is an expensive, high-performance 36-volt trimmer that lives up to its price tag. It has a robust line head with trouble-free bump line advance, even in tall weeds and difficult conditions. With the press of a button, you can make the head spin clockwise or counter-clockwise. This is helpful to untangle tall weeds from the head, we learned, and gives you greater control over where and how the trimmer ejects what it is cutting. This is a powerful trimmer that fells tall and thick weeds, dried stalks and does routine cleanup before or after you mow your lawn. With the 7.5-Ah battery, it weighs 11.8 pounds. We didn’t find it tiring to use and appreciated the massive battery’s run time, which you can conserve by pressing a switch to change between high and low speeds. The trimmer easily has enough power and run time to do a typical suburban yard, even a large one.
Two button's on the Husqvarna's control panel directs the line head to spin clockwise or counterclockwise. The ability to reverse head direction can help to disentangle weeds from the line head. It's also useful in edging and for control to direct where debris flies as you trim.
Many people will find a good string trimmer in the prosumer product category, tools and machines that are heavier than what a homeowner typically needs but are not quite beefy enough to suit a contractor. Ryobi specializes in this category, and its newest string trimmer is a case in point. It’s got more than enough power for normal grass, but—knowing its features—we reserved a stand of dried milkweed stalks and some light briers to test its power. It sailed through. Aside from a motor that produces decent torque, its string head is wound with a good quality twisted .095 line–stout stuff, we learned. Rewinding that line is simplified by a crank that the company provides with the RY40290VNM. Slip the gadget over the bump feed button on the bottom of the line head and crank it. The machine’s light weight makes it easy to handle and is achieved in part due to a carbon-fiber tube that houses the drive shaft.
Echo built its reputation on making a first-class string trimmer, and when you use this professional-duty machine, you see why. Its design is familiar. Anybody who has used a gas-engine trimmer can pick it up, purge the carburetor, choke the machine, and start it with a couple of pulls. Its strong suit is two-fold: It offers outstanding throttle response and torque, in part due to a great engine, but also a 2:1 gear reduction that multiplies that torque output. When combined with the rigid twisted-nylon line, it provides almost explosive cutting power.
Other well-designed features are a translucent gas tank that lets you see your fuel level and a semi-wrap skid plate that protects the tank and holds the trimmer upright when you’re laying the machine down. The handles are comfortable and the Echo is well balanced, enabling long trimming sessions.
Ego pulled out the stops in engineering this string trimmer. Start with the fact that you never have to bump feed the head. It feeds out string automatically. When you run out of string, feed a precut length of string through the head and press the rewind button at the end of the shaft. The string zooms into the head in seconds. Our test found the 56-volt brushless motor delivers power to spare and you have excellent control over that power with a two-speed selector switch that enables you to choose between going full out at vegetation or dialing back the speed if you find yourself cutting near delicate shrubs and you need to avoid collateral damage. That control is also improved with a telescoping shaft length; you adjust it to suit your tastes, and the shaft is carbon fiber. Its reduced weight also reduces your fatigue, further improving your control over the machine.
In the realm of outdoor power tools, the 20-volt Craftsman occupies a lightweight, light-duty niche. It’s an absolute pleasure to use. No, this isn’t a weed slashing brute. It weighs a mere 6.8 pounds with a single piece of trimmer string projecting from its head, and on its low setting it’s nearly whisper quiet. It trims effectively and neatly. A caveat here: it will work vertically edging, but only if you have a light hand. Its single .080 line will not take a whole lot of dirt impact. If you go easy, you’ll be fine.
Craftsman's line head is light duty, but it's effective providing you use a light touch. A single string projects from its line head.
The lightest pro trimmer in this test is this Makita, which racked up points for good industrial design and a host of features, from its solid-steel drive shaft to its three speed settings. Its specially designed, high-torque motor has an external rotor and is extremely smooth and quiet. It also provides a surprisingly high power-to-weight ratio. When coupled with the drive shaft, it creates one of the few trimmers that operates almost entirely without vibration.
All of the speed settings provide enough power for average jobs. The lowest sips current from the battery and provides great control, particularly when you turn the trimmer vertically like an edger. The low-speed setting also extends string life. We particularly love the momentary reverse feature. Push its switch and the head briefly counter rotates to clear grass and weeds that are wound around it. Speaking of that, the XRU15 excels in grass. It’s got enough oomph to cut weeds, but if you do a lot of that, the DeWalt or Echo SRM-2620 would be better choices.
Toro equipment is well behaved and we often breathe a sigh of relief when we find ourselves operating it. This 60-volt power head-string trimmer combination is no exception. Faultlessly smooth running and powerful, it hummed merrily through the grass test, the weed test and edging. We describe it as we tested it, a power head with the string trimmer attachment. Among its other accessories are a rotary cultivator, edger, and a pole saw. The machine weighs 12.4 pounds with the 2.5-Ah battery and string trimmer head. That puts it squarely in gas engine territory, as far as weight is concerned. Its build-quality-to-price ratio is also about what you would expect from a better quality piece of gas engine equipment. Unlike those two-stroke trimmers, this produces a fraction of the noise and–of course–there’s no stink from exhaust fumes.
The Toro trimmer is actually a powerhead and shaft that takes multiple attachments. In the case of this test, it was a very effective string trimmer head. But you can also uncouple the accessory by loosening the accessory-mounting fastener. Once the fastener is loosened, pull off the front shaft, and replace it with a chainsaw pole pruner, a tiller head, a reciprocating hedge trimmer head or other accessories.
Various Amazon brands we’ve tested haven’t been worth wasting time or money on. And to make matters worse, they’re multiplying like fungi in a dark closet. This string trimmer is an exception to the fungi rule, however. It’s part of the Denali line, an Amazon brand manufactured in China by Skil (or more properly, under the Skil aegis, itself a brand of Chervon). Denali tools are sold as a kit (tool, battery, and charger), and this little trimmer kit turned in a surprisingly spunky performance. The dual .080 line-head charged through weeds and tall grass like a champ, but we were particularly surprised at how well it did edging vertically. If you take a light-duty trimmer like this (emphasis on light duty) and work at that hard, be prepared to bump feed fresh line at a rapid clip. Other check marks for it: lightweight (7.4 lb) and a high speed/low speed switch.
Roy Berendsohn has worked for more than 25 years at Popular Mechanics, where he has written on carpentry, masonry, painting, plumbing, electrical, woodworking, blacksmithing, welding, lawn care, chainsaw use, and outdoor power equipment. When he’s not working on his own house, he volunteers with Sovereign Grace Church doing home repair for families in rural, suburban and urban locations throughout central and southern New Jersey.
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