What the best string trimmers have
- Light weight. Users bear the full weight of this tool, so it's important to select a lawn trimmer that's comfortable to carry and maneuver around your landscaping. Shoulder straps are available for some models to help remove the burden from your arms.
- Ample safety guards. The shield at the bottom of the string trimmer protects users from flying debris. Although a well-designed guard blocks most things, it's always best to wear safety goggles, closed shoes and pants to protect against airborne grass and rocks.
- A trigger lock. To prevent accidentally running the trim head when not in use, the best string trimmers use a trigger or throttle lock. This switch should be in a convenient location and easy to use.
- Quiet motors or engines. In general, electric (corded and cordless) lawn trimmers are quieter than gas-powered models, but noise levels vary in each class. In most cases -- and especially with gas trimmers -- wearing ear protection is recommended.
- Powerful trimming capabilities. If you need to take down unruly weeds and tall grass, look for a string trimmer that's equipped with dual nylon lines. Lines that are .08 inch or thicker cut through tougher vegetation.
- An edging option and clean finish. Some string trimmers have a swivel head that rotates to the ideal edging position. Others require you to turn the entire tool. Either way, the string trimmer should stay well balanced at any angle, giving you good visibility of the area you're trimming and leave a crisp edge.
- Low vibration. Gas engines are notorious for vibrating, which can fatigue your hands and leave them numb. String trimmers with anti-vibration technology are more comfortable to use over long periods.
- Good balance. The string trimmer should stay at the proper angle without a fight; this is usually easiest with a top-mount motor. The best string trimmers have shafts that change lengths or moveable loop handles that allow you to adjust the tool to match your height.
- Easy-to-use feed and reload features. Reviewers don't have a preference between bump-feed and automatic-feed systems, as long as the string trimmer delivers the line smoothly as needed. The best string trimmers have a spool that's easy to load with new line.
- Durable construction. The best string trimmers incorporate high-quality materials into a thoughtful design to create pull-cords, switches, spools and engines that can withstand years of use. Even expensive models may have some plastic, which keeps the weight down. But a longer warranty isn't a guarantee of a better tool; many owners report problems getting warranty service through some brands.
Know before you go
What obstacles do you trim around? Consider landscaping elements like trees, furniture and gardens that need to be edged or trimmed. A corded string trimmer is more challenging to maneuver around large items and it's harder to keep the cord from tangling.
How big is your property? More landscaping to trim also means more time required; choose a string trimmer that has the runtime to handle all of your trimming and edging at once. Cordless trimmers are the most limiting; some users purchase additional batteries to extend runtime, but they can be fairly expensive.
Straight shaft or curved shaft? Experts find that there isn't much performance difference between the two styles of string trimmer, but that each type is better for certain types of jobs. According to a blog post at the Echo web site, curved shaft trimmers are best for light trimming; "They are typically used for lawns that are covered in trees or areas with multiple posts that need trimming and require easy maneuvering," they say. Straight-shaft weed whackers are more heavy duty in general, and are best for properties where you will be doing a lot of cutting under things like bushes and shrubbery.
Gas or electric? Gas hedge trimmers are generally preferred for large properties and extended use, and they still do the best job of whacking away thick underbrush. However, gas engines require more care and maintenance -- and don't ignore makers' warnings regarding fuel storage and ethanol content in fuel -- doing so can lead to a costly repair that won't be covered under warranty. For most residential properties, a cordless electric weed eater makes lots of sense. Li-ion technology provides more run time than earlier generation string trimmers that used NiCd batteries, and deliver plenty of power to knock down tall grass, weeds, and more. However once the battery runs out, unless you have a charged spare on hand, your weed eating will be put on hold for an hour or more. Corded string trimmers are the least expensive option. They again offer good power for typical yards, but the cord limits their range, and wrangling the cord around trees and playsets can be a nuisance.