Hand pruning shears are used for removing whole branches, while hand hedge shears are designed to cut a number of small branches at the same time, more like giving the hedge a haircut. Hedge shears are designed to cut woody material up to ½ inch thick.
Hedge shears are large scissorlike devices coming from 12 to 28 inches in length. Handles may be wood or metal with rubber grips. Blades can be straightedged, curved, serrated, or wavy. The curves, serrations, waves hold branches in blace as the blades are closed giving a cleaner cut. The better models have some kind of rubber bumper system at the pivot point of the tool to absorb the shock of the two handles coming together.

Hand Hedge Shears vs. Power Shears
Hedges that are properly trimmed are not only attractive but the hedge will be more healthy. Cutting off new shoots makes the hedge grow dense and crisp instead of spindly and weak. A hedge trimmer is the tool of choice if the plant stems to be cut are not any bigger than 3/8 of an inch.

If the trimming job is modest, hand hedge shears may do just fine. This tool is going to give you some upper body exercise, so there are some features to look for. The better hedge shears have cushioned handle grips and a shock-absorbing bumper where the handles come together when in use. This reduces the wear and tear on your arms and joints. Hand hedge shears must be very sharp or the work gets harder and the job gets more ragged. Shears with a serrated blade will usually stay sharp longer. A little oil on the joint joining the two blades keeps the tool working best.

When the hedge trimming job takes more than an hour by hand, a power hedge clipper should be considered. You have much more control of the cut with a power tool and you can do a lot more cutting before you wear yourself out. These power trimmers have two blades, one above the other; the length of the blades determines how wide a swath they can cut. The most popular lengths are 16 to 20 inches.
For more information about power hedge shears click here.

Features to Consider
Gas vs. Electric - Electric hedge trimmers are quiet, light (five to eight pounds, easy to run and easy to maintain. The bottom blade is usually stationary and the top blade moves back and forth (called single action). They are perfectly satisfactory for most home trimming jobs. The gas trimmer is able to be used anywhere because there is no electric cord to haul around and the gas trimmer is more powerful so it will handle tough jobs where the material to cut is thicker than a pencil. With the gas trimmers both blades move reciprocally giving a better cut (called double action). With gas you have more noise, more weight, and more maintenance. If you have a need for the power of a gas trimmer for just one tough job, most rental agencies carry these tools.

Safety Features - All quality electric trimmers must conform to the safety standards set by the Underwriters Laboratories (UL), so look for the UL seal. Some gas trimmers voluntarily comply with the UL standards. Don’t buy a trimmer with a three pronged plug. That means the tool lacks double insulation which prevents shocks.

Tips For Safe Use
Whether you use a hand shears or a power trimmer, these tools can cause small objects to fly up into your face. So always wear safety glasses when using a hedge trimmer. Good solid shoes, long pants, and good gloves are also important. When using a gas trimmer, ear protection is definitely in order.

A good rule is to always hold the power trimmer with both hands when it is running. If you need to free up some material stuck in the blade, never reach over with one hand while the machine is still running. If you keep the two hand rule, then you will first turn off the machine and then you will free the material that is stuck.

Another good rule to follow is to not trim the hedge any higher than your shoulders when you are standing on the ground. You should always have both feet firmly on the ground in a comfortable balanced position. It is when you try to overreach and get off balance that accidents are more likely to occur. Does this mean you can’t work off of a ladder? Not at all. It just means that whenever you are working off the ground on a platform or off a ladder, your need to be extra careful about balance is most critical.

Basic Hedge Shears

This is a traditional design that still gets the job done.
 

GAS AND ELECTRIC POWERED HEDGE SHEARS