Electric string trimmers are finding more favor with environmentally conscious consumers. But even gas-powered trimmers are polluting far less than older models, thanks to tougher California and federal regulations. Several premium gas-powered models certify that their engines will meet those regulations for 300 hours, rather than the usual 50. More hours mean not only less pollution, but potentially longer engine life. But those premium trimmers typically carry a premium price, about $200 and up.
The best corded machines can trim, edge, and even tackle the tall stuff nearly as well some of the best gas models. And while cordless, battery-powered trimmers still aren't ideal for hacking away tall grass and weeds, some now do a decent job.
See how it feels
Handle the trimmer at the store to check its balance. After adjusting the front handle for a comfortable reach, hold the trimmer in the cutting position with both hands. Its weight should feel evenly distributed from top to bottom or slightly heavier at the top. Be sure that the controls work smoothly and are easy to reach.
Check the gap
Tall grass and weeds can slow or stall a trimmer by wrapping around the top of its cutting head, especially if there's a gap between it and the mounting for the grass-debris guard. Models with a small gap or a protective sleeve around the shaft sidestepped that problem in our tests.
String trimmers can kick up debris. To avoid injury, wear safety glasses or goggles and long pants and boots. All but the cordless electric trimmers we tested emitted at least 85 decibels, the point at which we recommend ear protection.
You don't have to invest in an expensive, professional-grade trimmer unless you need its metal-blade capability for cutting saplings and other woody waste. Most of the gas trimmers and even some electrics we tested can handle the grass and tall weeds that account for most trimming. Use this string-trimmer guide to decide whether a gas-powered or electric trimmer fits your needs.
Gasoline-powered trimmers are the best choice for tall grass and weeds. Many are at the low end of the 9 to 13 pounds most fall under, though they still outweigh corded-electric models overall. The latest run more cleanly but still produce exhaust emissions. And all are loud enough to mandate hearing protection. Some propane-powered models produce fewer emissions but cost more to run.
Corded electric trimmers
These cost the least and weigh well under 10 pounds. They don't require tune-ups, and they start with pushbutton ease. They're lighter and quieter than the gas models, but the power cord limits your range, and you'll still need hearing protection.
Cordless electric trimmers
Battery-powered string trimmers deliver cord-free mobility without fueling, fumes, and pull-starting. The best now trim and edge impressively, and perform reasonably well in tall grass. But top gas and plug-in models still beat them in the tall stuff. Cordless trimmers are also heavier than corded models and run about 30 minutes before they need a recharge, which can take hours. That means even the most capable models are still best-suited to smaller jobs.
Even the best-kept lawn won't look its best with untrimmed walks and tall grass poking up around trees and fence posts. The latest string trimmers address lawn-grooming issues with more performance and convenience for less money. Here are the string-trimmer features to consider.
Straight or curved shaft
The shaft transfers power from the engine or motor to the lines that do the cutting. Models with a straight shaft offer a longer reach, and they tend to be better for tall users and for reaching beneath bushes and other shrubs. Models with a curved shaft tend to be lighter and easier to handle.
In these models, the shaft comes apart to accept a leaf blower, edging blade, or other yard tools. Most such add-on tools haven't been very effective in our tests.
On some models, the head can be swiveled to a vertical position for edging.
Most manufacturers tell you which size replacement line fits your trimmer. Line that's too thin can compromise cutting power, while line that's too thick can bog down a trimmer's engine or motor. Trimmers with two lines cut more grass with each revolution than single-line models, so they can typically handle heavier growth.
Bump-feed line advance
This convenient feature releases line from a spool when you bump the trimmer head on the ground.
Instead of a spool, more consumer trimmers are using pro-style heads with short lengths of line to help eliminate jams and tangles associated with loading new line. Simply thread in a piece a new length of line as needed--though you'll have to do that relatively frequently. Fixed-line heads are also available as aftermarket items for many existing trimmers.
Many heavy-duty string trimmers have a shoulder harness for easier handling.
All gas trimmers have the engine mounted on top. Electric trimmers with a top-mounted motor tend to be better balanced and easier to handle than models with the motor mounted near the cutting line.
Trimmers that have the stop switch within easy reach let you quickly stop the engine or motor without moving your hands.
Four-stroke gas engines tend to start more easily than two-stroke engines. And they pollute less, because they burn straight gasoline instead of a two-stroke's gas-and-oil mixture. But four-stroke trimmers are heavier than most two-stroke models. Most gas-powered trimmers run on 87-octane regular, though some brands with high-engine compression recommend 89-octane fuel.
This feature lets a gas-powered trimmer idle without spinning the line, which is safer and more convenient than when the line keeps turning. (Electric models don't spin unless you press a switch.)
Spring-assisted starting makes pulling the starter cord of a gas-powered trimmer easier, and a relatively foolproof sequence for pushing the fuel-primer bulb and engaging the choke delivers the proper fuel mixture to a cold engine for faster starts.
Most gas trimmers have a deflector to aim hot exhaust gases rearward. That's important if you're left-handed.
Translucent fuel tank
On gas-powered models, a translucent tank lets you can see at a glance when fuel is low.
Black & Decker, Craftsman, Toro, and Weed Eater are the major brands for electrics, while Craftsman, Homelite, Ryobi, Troy-Bilt, and Weed Eater are the big names in gas-powered models. Leading high-end brands include Echo, Husqvarna, John Deere, and Stihl. Use these profiles to compare string trimmers by brand.
Black & Decker
Black & Decker is the leading manufacturer and marketer of corded electric and electric rechargeable string trimmers and offers an extensive line of electric products. Black & Decker string trimmers are widely available online and at Home Depot and Walmart.
Craftsman is a top brand in the string trimmer market. Craftsman string trimmers are available with two- and four-cycle engines and split-shaft designs for attachments. Craftsman products are sold at Sears and Kmart and at Sears.com.
Echo is the leading manufacturer and marketer of gas string trimmers. Echo products are used in the consumer and professional market. Echo string trimmers are available with two-cycle engines and split-shaft designs for attachments. Some models claim low noise, emissions, and weight and anti-vibration features. Consumers can find Echo string trimmers at company dealer stores and Home Depot.
Husqvarna markets a small line of gas string trimmers for both the consumer and professional market. These string trimmers are available with both two- and four-cycle engines, and many have split-shaft designs for attachments. You'll find Husqvarna string trimmers at Lowe's and dealer stores; prices range from $170 to $300.
John Deere manufactures and markets string trimmer gear to the professional market. John Deere string trimmers are available with two-cycle engines and split-shaft designs for attachments. Some models claim low noise and weight and anti-vibration features. Consumers can find John Deere string trimmers at company's dealer stores.
MTD markets electric and gas string trimmers under the Yard Man, Yard Machine, Troy-Bilt, Cub Cadet, and White Outdoor brand names. MTD's diverse line of string trimmers includes electric and cordless types, models with two- and four-cycle engines and split-shaft designs for attachments. MTD products are sold at a broad array of retailers including Sears, Tractor Supply, Lowe's, Home Depot, and Walmart.
Stihl is a leading manufacturer and marketer of gas string trimmers. These premium-priced products are for consumers and pros. Stihl string trimmers are available with both two- and four-cycle engines. One model in the line is electric, and many have split-shaft designs for attachments. Some models claim features that reduce noise, emissions, weight, and vibration. Consumers can find You'll find Stihl string trimmers at dealer stores; prices range from $130 to $400.
Toro manufactures and markets a line of electric string trimmers. These electric trimmers are small and lightweight. Toro string trimmers are sold through dealers and Home Depot.