Corded electric hedge trimmers are the least expensive and most popular type for residential use. They are quiet and don't have the added weight of a battery or a tank of gas. Reviews say they're powerful enough for most trimming jobs, although they're more likely to be able to cut branches up to half an inch in diameter than to be able to handle branches up to 3/4 inch thick, as most manufacturers claim they can do.
Dealing with the extension cord is the main downside -- you must remain within reach of an electrical outlet and keep the cord from becoming entangled in branches while you're working. To make sure the extension cord stays securely plugged in, look for a trimmer that allows you to plug the extension cord into a short pigtail cord. Electrical hedge trimmers should only be used when the foliage and grass is completely dry to avoid the risk of an electrical shock.
Cordless hedge trimmers operate on a rechargeable battery. Like corded models, they are quiet and relatively lightweight. Those people who find operating a power tool with a sharp blade to be challenging may find cordless models to be safer to operate -- there's no power cord that could be inadvertently cut with the blade or become entangled in branches. However, cordless models are the least powerful trimmer type, so they tend to bog down on thick hedges. Battery runtime is limited to about 45 minutes at most, though if you have extras on hand, you can swap batteries to keep going. The commercial-grade 36-volt Stihl HSA 65 is an exception in this category; it is as powerful as gas-powered hedge trimmers, according to some reviewers, and its battery has a longer runtime. However, it is expensive, and heavier than other cordless models.
Gas hedge trimmers are more expensive than electric and most cordless hedge trimmers, but they are powerful and get the job done fastest. This makes them a favorite among yard maintenance professionals. Additionally, they aren't constrained by the location of an electrical outlet or battery runtime. However, they're noisier and heavier than electric models, and you'll be breathing in fumes while you use one.
Safety and ease-of-use are other important considerations in choosing a hedge trimmer. Models that shut off automatically if either hand is taken off the handle eliminate the risk of having a moving blade come in contact with your hand. However, users reviewing hedge trimmers at sites like Amazon.com clearly prefer hedge trimmers with a lock-on switch, because this makes the tool easier to maneuver and less tiring to use. A lightweight and balanced trimmer is less fatiguing to operate, and a comfortable handle and trigger are essential for large trimming jobs.
Another key difference among hedge trimmers is the blade design. Experts say to consider the following advice about blades when shopping for a hedge trimmer:
Expert reviewers say it's much safer to groom tall shrubs using a pole hedge trimmer -- available as electric, cordless or gas models. These have a blade attached to an adjustable pole rather than a handle, and the angle of the blade is also adjustable. This makes it possible to trim the top of a tall hedge while standing on the ground, rather than risk falling off a ladder with a blade in your hand. Pole trimmers are also useful for trimming behind shrubs or along low ground cover.