Popular electric hedge trimmers have two blades with multiple teeth. One blade moves back and forth over the other, shearing the plant material as the teeth on the two blades pass each other.

Hedge trimmers may not be as popular now as a few years ago because more people now realize that it’s healthier for plants to be selectively pruned rather than sheared.

Nevertheless, shearing plants to shape is appropriate in some situations, says Dr. Dick Parish, an engineer at the LSU AgCenter’s Hammond Research Station.

The formal, sheared look is still attractive to many people, Parish says. And a hedge trimmer is usually the best tool for the job.

"Most of us are familiar with the old, long-nosed hedge clippers that have been around for generations," Parish says. "These shears require some muscle power but may be the best solution for one or a few small bushes. They are certainly the least expensive and safest option."

Parish says many people use electric hedge trimmers that have two blades with multiple teeth. One blade moves back and forth over the other, shearing the plant material as the teeth on the two blades pass each other.

Electric hedge trimmers are available with battery or 120-volt power from household electric outlets.

"They’re light and easy to maneuver," Parish says. "The battery models have less power than the 120-volt models, but they also dispense with the need for a cord."

The engineer says some electric trimmers can cut with both sides of the blade, making them handy when cutting in awkward positions. Electric trimmers are the tool of choice for most homeowners since they’re inexpensive, quiet and reliable and require little or no maintenance.

Parish says professionals, on the other hand, prefer hedge trimmers with small 2-stroke engines. They’re also appropriate for homeowners who have many plants to trim and/or plants in areas not readily accessible to electric power. They offer complete versatility and freedom of movement.

Some hedge trimmers have the engine at the base of the cutting head; others have the engine at one end of a long tube and the cutting head at the other end. This configuration allows the operator to extend his reach.

"The downside," Parish says, "is that this type is heavier and more expensive."

As with any tool using a 2-stroke engine, oil must be mixed with the gasoline. Noise and exhaust fumes are negatives with gasoline engines, and maintenance will be higher than with electric trimmers.

Parish says safety should be a major concern.

"With any hedge trimmer, you should keep both hands on the trimmer handles," he says. "It’s much more difficult to amputate a finger if they’re grasping the handles.

He also recommends wearing gloves when using a trimmer, and cut-resistant gloves give the most protection.

One problem with corded electric trimmers is the potential for cutting your cord with the trimmer, Parish says. In addition to being inconvenient and embarrassing, this can cause electrocution. It is important to run electric trimmers or any outdoor electrical tool from a GFCI-protected outlet or use a GFCI-protected extension cord.

With any gasoline engine-powered tool, you need to be very careful with gasoline and not add fuel or even open the gas tank when the engine is hot, he warns. A hot muffler is another hazard to avoid.

"Hedge trimmers are simple tools that can make short work of shearing hedges or individual shrubs," Parish says. "They won’t cut heavy branches, but they’ll cleanly cut small branches up to about 1/4-inch in diameter. And they’re easy to use."

The type of trimmer you need depends on how much you have to trim and how accessible the area is, Parish says. And a few reasonable safety precautions will help prevent injuries.

More gardening information is available at your local LSU AgCenter office. In addition, look for lawn & gardening and Get It Growing links in the LSU AgCenter Web site: http://www.lsuagcenter.com/.