Tree pruning tools

Flower & Garden Magazine, Jan-Feb, 1997 by Robin Pendergrast

Prune properly -- using the proper pruning tools -- to ensure the long-term health and vigor of your trees and shrubs.

When you're cleaning the twigs and branches off the lawn after a windstorm, you can see that pruning is a natural, continual process in woody plants. In learning to cultivate trees and shrubs, we have harnessed the concept of pruning, replacing the often violent, seemingly random natural process with a kinder, gentler strategy that has three primary goals:

* Help woody plants recover more quickly from natural injury.

* Remove branches that have little chance of long-term prosperity.

* Direct the plants' growth to encourage production of strong branches -- to increase fruiting and flowering and help the plant to lead a long, vigorous life.

With the proper tools, the gardener can help woody plants realize their full potential -- whether the plant is a fruit-bearing tree, a flowering shrub, a hedge used as a wind-break or that favorite shade tree with a swing hanging from a mighty lower limb. Sensible pruning does not hurt plants. The damage is done when pruning is excessive or ill-planned, such as when the top of a tree is lopped off or a shrub is trimmed in a way that deprives leaves of vital sunlight.

Occasional pruning may be necessary throughout the life of a tree or shrub. Major pruning that would significantly reduce the amount of foliage should be performed little by little over a period of several years. Each species tolerates only a certain percentage of limb removal in any one year. A plant growing in less-than-optimal conditions may tolerate less pruning than would the same plant in a better location. Before pruning, learn what is best for your particular plants. Gardening books and your local extension office offer a wealth of information.

Natural self-pruning occurs through ongoing competition among branches. The tree feeds the limbs that bear leaves in the outer canopy, where exposure to sunlight is highest. These fortunate limbs grow longer and produce a dense leaf cover, shading older limbs lower on the tree and closer to the main trunk. Sun-deprived limbs gradually lose their food supplies and die. Limbs also may die if two of them grow so they touch, rubbing away each other's bark, cutting off food supply and weakening the limbs' vigor.

On some trees, like Siberian elms, dead wood snaps off easily in a strong wind. On others, like certain oaks, dead wood becomes rock-hard and may remain in place for decades.

Dead wood poses risks to a tree's long-term health. Insects and disease organisms can attack through a ragged stub left projecting from the trunk. If a large, weak limb falls off, its downward plunge can peel a strip of bark off the trunk, opening a large wound. And dead limbs can detract from a tree's beauty.

Proper mechanical pruning corrects these problems. Good, sharp tools, accurately used, leave a smooth surface that heals quickly as new bark grows to cover the wound.

HIGH-LEVEL TOOLS

Modern tools make it easier than ever to make proper pruning cuts. Tree research has found that one of the messiest tasks -- the application of pruning paint to a cut -- is totally unnecessary, as the paint disrupts the natural healing process and does more harm than good. That's great news. Using an extended-reach pruning tool, the gardener can remain firmly on the ground while making pruning cuts high overhead. And there's no reason to climb up the tree afterward to apply brush-on or spray paint.

There are several kinds of extended-reach pruners. A popular type is a lopping shear at the end of a pole. The lopping blade is controlled from ground level via a cord that passes through pulleys. Pole pruners are convenient for removing smaller limbs, like those on fruit trees. Large limbs or harder woods may require an extended-reach saw. Many models of pole pruners combine a fixed-blade saw and a lopping blade on one pole, allowing gardeners to cut limbs of various sizes with the same tool. The poles, in fiberglass or wood, are typically 8 feet, 10 feet or 12 feet; some models offer sectional poles that can be disassembled for storage. Pole pruners with both lopping and saw blades range in price from about $40 to more than $200.

Another tree-pruning tool that allows the operator to remain on firm ground utilizes a 2- to 4-foot length of modified chainsaw blade. Attached to each end of the chain are ropes 25 feet or so in length. One end is weighted so it can be thrown over the limb to be cut. Once the chain is placed atop the limb, the cut is made by pulling alternately on the two rope ends. Expect to pay $30 to $40 for this type of manual pruner.

Although effective, these cutting tools can require considerable "elbow grease" to operate. And manual pole pruners are generally ill-suited to perform the three-cut sequence recommended for removing larger limbs that may rip off bark when they fall.

Extended-reach power pruners solve these problems, focusing the gardener on the pruning strategy rather than the sweat needed to make the cut. Such machines generally feature a two-cycle gasoline engine at the bottom of a shaft, with either a chainsaw blade (8- or 10-inch cutting length) or a reciprocating saw blade (which cuts on both the forward and backward strokes) at the other end. Electric pole pruners with small chainsaw blades are also available, in plug-in or battery-powered styles. Pruners developed for home use have a shaft length of about 6 to 8 feet; optional extensions on some models allow an average-height person to cut limbs up to 16 feet high while standing firmly on the ground. For many homeowners, such a machine -- designed to safely distance the operator from the cutting blade -- may be practical both for tree pruning and in place of a light-duty chainsaw.