A Primer on Pruning Shears

Much of what I have written on tree care deals with pruning?where to make a cut, when to make it, how to make it, etc. With this months focus on equipment, it occurs to me that I may have been remiss in not ever covering the selection, use and maintenance of the most basic tool of the trade?pruning shears, also known as hand pruners.
 
Pruning shears come in two basic styles; bypass shears, and hammer and anvil. Bypass shears have a cutting action based on the same principle as an ordinary pair of household scissors, in that a curved cutting blade passes tightly by another finely honed, but thicker blade. Hammer and anvil shears feature a straight blade that descends down upon a wide flat bed of steel. Of the two, bypass pruners are far superior. A moderate to good quality pair of bypass pruning shears, well sharpened, will easily remove branches up to approximately ¾ inch diameter, without causing undue damage to the wood left behind. On the other hand, hammer and anvil shears, no matter how sharp, cause bruising of tissue on the branch left on the tree, and subsequent dieback of wood. While the wounds created are small, the additional damage caused by hammer/anvil style pruners is significant, especially when multiplied by the hundreds or thousands of such small cuts that a tree may suffer.
 
Bypass pruners (better to use)
 
Anvil pruners (crushes wood as it cuts)
 
While bypass pruning shears are definitely superior to hammer/anvil, there is a wide spectrum of quality and features available to the arborist. As with so many other things in life, you often get what you pay for. One of the biggest differences in pruner quality is in the mechanism used to adjust tightness between the blades. In cheaper pairs, this function is provided by a simple nut extending slightly out the side of blade junction. The problem here is that the nut often works itself loose. The looseness is noticeable by sloppy cuts inflicted when the pressure of the cutting action forces the two blades apart from one another, and the arborist is forced to stop and take the time to once again retighten. Higher quality shears have an additional part or two designed to completely lock the tightening nut in the desired position. The few extra dollars spent for this feature are usually quickly recouped by the time saved from not having to retighten.
 
Many other differences in features are available. Some pruners have handles that are ergonomically designed, creating much less fatigue and stress when used over long periods of time. A simple difference in the shape of the handles, some of which are much more comfortable to use, can make a large difference over the course of a working day. Some pruner manufacturers have shears designed specifically for use by left-handed people. Another feature available is when one of the two handles is designed to smoothly rotate in the palm, again relieving physical stress for the user. Personally, this feature has never felt quite comfortable to me, but I think that may be because I spent so many years without it, that now it just doesn?t feel ?natural?, even though I once attempted to use them for an extended period of time.
 
Other, more fancy features are available as well. These include pruning shears that have ?power assist? available in the form of a pneumatic air tube hooked to a generating device hooked to the belt. While the effort required to cut is itself greatly reduced, this advantage is balanced against their cumbersome nature, and I know of no arborist who uses them. Another of the more fancy features available is a set-up, similar in style to the power assist, which delivers a fine spray of disinfectant to the blades with each cut. The same disadvantage of cumbersome nature applies here as well.
 
Now that we?ve covered most of the differences in quality available for purchase, a few words are in order about proper use and maintenance.
 
There are two important points I want to drive home on proper use of pruning shears. First, never attempt to use them to cut through wood larger than what they can easily handle. If you are required to use excessive force to make the cut, use loppers, or better yet, a handsaw to make the cut. The excessive force required to cut through too large a branch will leave the wound bruised, and often jagged or uneven.
 
The other point I think is worth mentioning is that the user should practice and become accustomed to always cutting with the narrow blade adjacent to the wood left behind, and the wider blade positioned on the branch to be removed. This is because the wider blade can prevent the shears from being positioned as close to the remaining branch as one might desire, and result in a small ?stub-cut?. While it takes some practice and diligence to get used to the practice of flipping the shears over in one?s hand as different angles and approaches to cuts are made, with time this practice becomes entirely automatic, and results in much better placed cuts.
 
As for maintenance of pruning shears, frequent sharpening and honing of the narrow cutting blade is very important. The sharper the blade is, the less effort required of the user, and the ?cleaner? the wound left behind. It is important to note that only the narrow cutting blade should be sharpened, and not the wider ?bed-knife? portion. If the bed-knife is filed or honed, the precision of the cutting action can be greatly reduced. Frequent lubrication of the shears is also desirable
 
Finally, without going into detail, disinfection of pruning shears is a very important consideration whenever one deals with the potential or reality of plant disease. Shears and other pruning equipment often spread disease. If disease is known or suspected to exist within a plant, pruning shears should be disinfected after each cut. It is also a very good idea to always sterilize equipment after each tree is completed.
 
Hopefully this article will help you in choosing, using and maintaining that most essential of arborist and horticulturist tools?the pruning shear.