Pruning Trees & Shrubs
Pruning is the selective removal of plant parts to achieve a specific goal. Any pruning you perform should be for a definite reason and should remove no more than necessary to achieve your objective. Often, people fail to realize that many trees and shrubs require little pruning to thrive and achieve good form. Some simply require the proper training when young and little more. A brief overview of woody plant growth will help you understand plant responses to pruning and when it’s appropriate.
The portion of a trunk or branch that can actively grow consists of a small layer just inside the bark—the cambium. After a bud has initiated a shoot, the cambium gives rise to all new growth in the stem. When you prune, you leave a wound that mostly consists of tissue (wood) that cannot grow and, therefore, cannot heal itself. Healing must commence from the perimeter of the wound, where the cut dissected the cambium. The cambium grows over the wound from the outside in, with a special kind of growth called callus (see Figure 1, at left). Because of this pattern, larger wounds take far longer to heal than smaller ones and so remain vulnerable to infection longer. Your pruning choices should take this into account and minimize the size of the cuts you make. In practice, this means not only selecting the smallest possible branches to cut but also cutting just above the branch collar, which we’ll discuss later in more detail.
Another principle to remember is that terminal buds (see Figure 2, below left) hormonally suppress the growth of lateral buds lower on the branch. Thus, pruning that removes the terminal bud releases remaining buds to grow. Pinching and heading back prompt branching in this way. Stubbing larger branches often releases many dormant or latent buds, resulting in a mass of new shoots. However, pruning to a lateral branch creates a new terminal that will function just as the old one you removed.
The spot from which leaves, buds and lateral shoots arise is called the node. The space on the stem between nodes is the internode. This arrangement is easy to see on young shoots but becomes obscure on older branches.
Pruning removes carbohydrate reserves (stored in wood), as well as foliage, which produces additional carbohydrates through photosynthesis. Removing these food sources reduces the plant’s ability to support its root system, which may die back if you remove too much of the shoot system. A tree may require several years to recover from severe pruning and the resulting stress makes it more vulnerable to pests, diseases and environmental extremes.
A properly trained tree or shrub should never need severe corrective pruning. In reality, however, the landscape professional often faces badly neglected plants that need a great deal of pruning to reacquire good form. Even if plant size is not an issue, crossing, dead, broken or low-hanging branches and sucker growth may comprise a large portion of the crown. Although every species responds differently to the removal of large portions of the crown, it generally is prudent to extend the process of corrective pruning over 2 or 3 years if you think you’ll need to remove more than about one-third of the crown.
WHY WE PRUNE
You should not prune in a manner inconsistent with the natural form of the plant. For instance, you should never top trees that grow with central leaders. Even if you are unfamiliar with a species, a visual examination of the plant should give you some idea of its growth habit. The reasons to prune are several and may include:
- Removal of crossing branches
- Improving structural integrity
- Influencing flowering and fruiting
- Thinning to improve light and air penetration
- Crown raising
- Removal of dead or diseased limbs
- Improving plant appearance
- Training young plants
- Controlling plant size.
Let’s look at some of the specific ways we achieve these goals (see Figure 3, at left).
> Removing crossing branches. Branches should be consistent with the general, natural form of a tree or shrub. Limbs that clash with this form disrupt visual appeal—spreading, horizontal branches clash with the form of an upright-growing tree, and upright branches conflict with a spreading form. Further, these branches often cross other branches and may rub against them, creating wounds that could lead to infection. Therefore, crossing branches are candidates for removal.
>Improving structural integrity. Narrow crotch angles tend to produce weak unions and are prone to wind breakage. Removing the susceptible branch reduces the chance of it splitting off. Remove any other limbs that pose a hazard, such as those that show a crack, as well.
>Influencing flowering or fruiting. Timing and severity are the two aspects of pruning that most influence bloom. The section on “Timing” (page 84) discusses pruning times. Landscape professionals often prune shrubs that bloom on current growth rather severely to encourage more of the new growth that will bear flowers.
>Thinning. Many trees and shrubs benefit from additional light penetration to the inner leaves and branches, and increased air circulation also may help. Further, thinning can improve the structural integrity of a plant. You also may wish to thin to emphasize attractive structural features of the plant.
You should perform thinning cuts only after you’ve finished other pruning. That is, after you’ve removed crossing, dead, diseased and broken branches. Do not think that you must thin every time you prune. If, after you finish other cuts, the tree or shrub seems to have good balance and appropriate density, leave it as it is.
The particular thinning cuts you make often are, to some extent, a matter of judgment. However, the appropriate
cuts are more obvious after you’ve made your other cuts. Some species branch more densely than others, so thinning cuts depend on the species in question.
>Limbing up or crown raising. As trees age, branches become heavier and may hang so low they interfere with activities such as mowing or walking. These branches need removal and this is called limbing up or crown raising. This generally is a simple matter. Cut back to a strong lateral branch or clear to the trunk. Crown raising when trees are in full leaf is easier because you can see how low branches hang with the full weight of their foliage. Be careful not to cut back to laterals that are completely and deeply shaded by the canopy. These branches often die due to light deprivation and may require elimination later.
>Desuckering. Suckers—also called water sprouts—arise as vigorous shoots from the trunk or roots. Some species naturally tend to produce suckers while others produce few or none. Suckers usually grow contrary to the form of the tree and may end up crossing other branches. Plus, suckers often sprout from root stocks of a variety different than that of the grafted cultivar. Thus, you always should remove suckers the same year they sprout. Hand shears generally are adequate for this task.
>Removing dead and diseased branches. If a branch has been dead for some time and the collar is healing around it, cut back to the living collar but no further, even if this leaves a large stub. You should allow the collar to continue to grow to seal off the dead wood.
Remove diseased branches as soon as possible to prevent spread of the disease. This often is an effective practice if you cut well below the visible symptoms. However, you should identify the disease before taking any steps. Having done so, you then can find more specific information on control measures—chemical remedies, sanitation and so on.
Another point to remember is that when pruning diseased
branches, you may be contaminating your tools with a contagious disease. Therefore, disinfect your shears or saw between each cut to avoid spreading the disease to other plant parts or plants (see Chapter 15 for more information on disinfecting tools).
>Improving plant appearance. This is a catchall category that actually encompasses many of the other reasons for pruning. Though references often cite “improving appearance” as an objective of pruning—and this is inarguable—pruning for the reasons discussed above usually results in the desired plant appearance. However, even if it offends in no other way, you may wish to remove the occasional odd branch that protrudes from a tree’s or shrub’s outline.
>Training young trees. Pruning young trees is an important task that, if performed properly, produces a superior, relatively maintenance-free specimen in maturity.
The first pruning. When you first plant a tree, the only pruning necessary is that which removes broken, dead or diseased branches, and root suckers. Although recommendations in the past suggested pruning to balance the crown with the root system, research shows that this is not a wise practice. Any removal of branches other than those mentioned above will slow establishment. Branches store food reserves, and leaves are the site of photosynthesis. Thus, removing them eliminates resources the tree needs to grow a healthy root system and establish itself quickly.
The second pruning. Allow 2 to 4 years for the tree to become established. Then, prune to remove problem branches (crossing, dead or diseased branches and those with weak branching angles) and half of the temporary limbs. Temporary limbs are those that branch from the trunk at a point lower than where you’ll want the lowest limbs on the tree when it’s mature. The exact height depends on the intended use of the site. Don’t remove too many of the temporary limbs at this time. For the tree to develop a healthy trunk taper, half of the young tree’s foliage should be on the lower two-thirds of the trunk. This distribution and the resulting trunk taper provides strength and good wind resistance.
After you’ve removed the temporary limbs, select the permanent scaffold limbs. Remove or cut back branches that turn in toward the trunk, extend beyond the natural outline of the tree or droop uncharacteristically. Then look for the healthiest limbs that are closest to being horizontal and are spaced 12 to 18 inches apart on the trunk. Remove limbs that are more upright or more closely spaced.
The third pruning. Prune again 5 to 7 years after transplanting.
This pruning involves minimal cutting if you performed the previous work correctly. At this time, remove dead or dying branches, codominant leaders and root suckers. If any limbs protrude from the tree’s natural profile, head them back to a lateral branch within the tree’s crown. Also remove suckers and crossing
>Controlling plant size. The need to reduce size implies that the plant was a poor choice for the site. Unfortunately, this often is the case and reducing size may be preferable to outright removal. You should never reduce size by topping. Topping is so injurious to trees that many die within a few years of being cut. Others that survive the short term may slowly decline. Unfortunately, topping is a common practice in spite of its detrimental effects.
A better practice is to reduce size by drop-crotching (see Figure 4, right). This entails cutting limbs back to lateral branches at least one-third to one-half the diameter of the branch you cut. This technique may require several years for significant size reduction, but it is the safest way to reduce tree size. After you remove higher branches, lower branches will more quickly grow, and you then can cut back to these laterals in a year or two. Thus, over time, you can bring the height of the tree down considerably, but gradually and with much less trauma to the tree. The branches to which you cut should not diverge at an angle of greater than about 45 degrees and should point to the outside of the tree crown.
Heading back, or stubbing, is another common technique for reducing size. Some references refer to heading as cutting back to a lateral branch. However, this essentially is no different than thinning or drop-crotching. We use heading here to mean cutting back to a stub. Heading back small branches (current or 1-year-old growth) is an effective means of forcing young shoots to branch. However, heading larger limbs is a poor alternative to drop-crotching and is no different from topping—it is damaging and results in vigorous sprout growth below the cut. These shoots are weakly attached and break off easily. Thus, they make undesirable replacement limbs.
The same basic techniques apply to most types of pruning. However, you need to adapt them to each specific kind of plant. Thus, there is no substitute for a thorough knowledge of plant material and the needs of each species. A good horticultural reference should provide pruning information specific to individual species.
• Choosing cuts. Before you make each cut, visualize what the plant will look like afterward. This type of mental deliberation forces you to think about what you are doing and whether a cut will achieve your pruning objective. If the branch removal will leave a void, throw the plant out of balance or otherwise damage its appearance, it probably is not a good choice unless there is an overriding reason to remove the branch, such as disease.
If you have a choice of which limbs to cut (all else being equal), choose the cut(s) that will produce the smallest wounds. One- and 2-year-old shoots have a high proportion of their mass in living cells that quickly react to environmental changes and usually have ample food reserves. Thus, shoot collars on young shoots react well to pruning wounds. Older shoots react more slowly to wounding because a greater proportion of their mass resides in declining inner annual growth rings. Pruning cuts on shoots that possess heartwood can lead to many problems. To minimize disease and decay, prune the youngest wood possible. The ideal pruning cut is one that heals and closes in the shortest time possible. Here are the basic principles involved in pruning most trees and shrubs:
• Making clean cuts. Pruning wounds should always be clean; that is, they should be smooth and free of split wood, stripped bark and ragged edges. If you make a cut that leaves a ragged surface, clean it up with additional cuts. Dull or bent shears are a common cause of rough cuts.
Trying to cut a branch that is too large is another reason a cut may not be as smooth as it should be. If you have trouble cutting a branch with shears, use a saw. Branches over 1 inch in diameter may be candidates for saws, although
some shears can accommodate branch diameters of 1.5 inches or even slightly larger. Saws will not leave a cut surface as smooth as shears, but a proper saw cut should still be reasonably clean.
• Angle and position. When cutting a lateral with shears, position the hook to the outside of the cut (see Figure 5, at left) to avoid bruising the tissue remaining below the cut. With this positioning, the hook will press against the portion of the branch you’re eliminating. Also, this orientation allows you to cut with the blade closer to the trunk or branch junction. When cutting back to a lateral, angle shear cuts up or sideways. This requires less effort on your part. Plus, this avoids branch splitting, which often happens when cutting downward at a branch junction. When heading back an unbranched shoot (see Figure 6, above left), cut diagonally instead of at right angles to the branch. Again, this requires less strength and causes less damage to the stem tissue.
Always cut just above a node. Cutting back to a lateral branch forces this to happen automatically because, by definition, this is where branches arise. When heading back young, unbranched shoots, cut 0.25- to 0.50-inch above the node, leaving a very short stub. Do not cut closer than this, as this will jeopardize the bud nearest the cut. However, if you cut too far above a node, you’ll leave an obvious stub because branching can only initiate from nodes. You can direct the growth of smaller branches by heading back to a bud oriented in the direction you wish growth to proceed.
Avoid leaving long stubs when removing a lateral branch. Stubs may encourage disease and are unsightly. At the same time, you should take care not to cut too closely. Most branches exhibit a collar of tissue around the base of the branch (see Figure 7, above, middle). Never remove, cut into or otherwise damage the collar—it consists of tissue that will help heal over the wound left by pruning. Therefore, avoid flush cuts, which damage or remove the collar. For the same reason, you also should leave the bark ridges (which function like a branch collar) intact.
With these concepts in mind, you can see that no one proper angle exists for every cut. The appropriate angle simply depends on the orientation of the collar or bark ridge (see Figure 8, above right).
• Cutting large limbs. When cutting large branches (see Figure 9, above) with a saw, make the first cut about one-fourth of the way into the bottom side of the branch, several inches above the site of the final cut (the branch collar). Then cut completely through the branch from the top side, just above the bottom cut. This way, when the branch drops, it will not pull a strip of bark from the trunk as it drops. You then can cut the remaining stub away without fear of damaging the trunk. Remove very heavy stubs with two cuts—the first from the bottom and the second from the top. Remember not to cut into the branch collar. Even on smaller limbs, it’s a good idea to make a shallow cut into the underside of the branch before cutting from the top to avoid stripping bark from the trunk as the branch falls.
Cut narrow crotches that display a bark ridge in a similar but modified way. Cut away the branch, leaving a stub as just described. Then, cut from the bottom side of the junction upward at a 40- to 50-degree angle to the point of divergence (see Figure 10, right).
Do not apply wound dressing or tree seal to pruning wounds. This is a practice that still persists to some extent, but research has not demonstrated benefits from wound dressing. At the very least, it is a waste of time and it may even encourage infection.
Several factors, such as flowering, and pest and disease problems, determine the proper time to prune.
• Flowering. A general rule of thumb is to prune spring-flowering species in the summer (immediately after bloom) and summer-flowering species in the winter (before spring growth commences).
Because spring-flowering plants bloom from buds that formed during the summer and fall of the previous season, pruning immediately after bloom allows season-long growth of the shoots that will bear the following year’s flower buds. Pruning them in the winter would simply eliminate the bloom for which you’re presumably growing the plant. Examples of spring bloomers include forsythia and redbud.
Summer-flowering plants bloom from growth of the same year. Winter (dormant) pruning does not remove flower buds, which will not form until after growth commences in the spring. Therefore, winter is the preferred time to prune summer bloomers. Examples include roses and crape myrtle.
The proper time to prune—other than when dictated by flowering—is open to some debate and may not be critical in many cases. However, most authorities agree that springtime—during the growth push—is not a good time. Summer and winter pruning both may produce acceptable results.
• Winter pruning. Minimizing the length of time pruning wounds remain open is an important consideration. By this logic, winter or early spring—just before spring growth starts—is the best time to prune. Healing starts as soon as spring growth begins.
An advantage of winter pruning is that leaves of deciduous plants have fallen and the branch structure is more visible. This makes it easier to choose your cuts. Also, pests and diseases
are inactive in most regions during the winter and so cannot take advantage of fresh pruning wounds to gain entry into the plant. In any case, winter is a convenient time to prune, because it is a less busy time. For these reasons, landscape professionals usually—and properly—think of pruning primarily as a dormant-season activity.
• Summer pruning. In summer, when plants are in full leaf, you can see dead or diseased branches more easily. Further, foliage weighs on low limbs so you can better decide which of them may interfere with activities by hanging low. Pinching to encourage branching and sucker removal are other types of pruning that you may wish to perform in the summer. Thus, some types of pruning are appropriate during summer.
Authorities do not generally recommend autumn as a time to prune. Pathologists note that many pathogenic fungi sporulate at this time, possibly rendering pruning wounds more susceptible to infection. However, trees that are prone to bleeding from pruning wounds—such as birch, elm and maple—may bleed much less if you make cuts in autumn. Even though bleeding usually is harmless to plants, it can be unattractive. Therefore, fall pruning may be a solution if you wish to minimize bleeding.
Fresh pruning wounds may attract some wood-boring insects. It is worthwhile to check with a local extension adviser for advice on when to prune species susceptible to borers in your region.
Shrubs generally require pruning for much the same reasons—and by the same principles—as trees. However, controlling size is a more frequent concern with shrubs, especially those growing near structures or walkways. In these cases, a regular pruning schedule may be necessary to avoid the need for larger cuts. Shrubs also are commonly sheared, which we’ll discuss later.
Some professionals provide “rejuvenation” or “renewal” pruning to old, large shrubs that seem to have lost their vigor but display no other symptoms. This involves stubbing the plant back to a few large branches, often close to the ground, and relies on resprouting to reestablish a new framework of branches. Such harsh treatment often succeeds, but it is not recommended unless the shrub has declined to the point where this is your only option. You can do this gradually by removing one-third to one-half of the old branches the first year. The second year, new shoots will have grown, and you can remove the remaining old branches without completely denuding the plant.
Shrubs that produce new shoots from ground level often succeed best with basal pruning. That is, removing large or declining shoots at ground level. This controls height, keeps the plant thinned, avoids stubs and often requires less labor. Forsythia and Nandina domestica are common examples of shrubs that work well with this treatment.
Roses require cane pruning. This entails cutting the branches back to several 1-year-old canes each year during dormancy, with the uppermost bud pointing outward. The length and number of canes you leave depends on the vigor of the plant and how much new growth you wish to encourage (remember, roses flower on new growth). References dealing entirely with roses discuss this type of specialty pruning in great detail.
Conifers whose branches grow in whorls, such as some pines and spruces, often require little pruning except for the occasional dead or broken branch and perhaps limbing up. However, you may wish to force more branching in some species by pinching out parts or all of the new shoots, or candles. Pruning whorled conifers must consist of either this or cutting back to a lateral branch. Heading back into old wood, even if it still bears foliage, will not force any new branching, leaving a stubbed plant.
Random-branching conifers—junipers and yews being two examples—are not so limiting. These conifers can produce shoots from older latent buds. However, avoid stubbing bare wood; these branches will not produce new shoots (yews are an exception to this rule).
Palm trees do not normally require pruning for their own benefit, except for transplants. Landscapers typically prune off fronds of transplanted palms, leaving several at the top to protect the tender apical bud. On established palms, however, older fronds either fall or remain attached to the trunk as they die, but they do not affect the health of the tree if they remain on it. Still, for the sake of a tidy appearance and to prevent fire hazard, landscape professionals typically remove older fronds from ornamental palms as the leaves age.
If the fronds are still green, some pruners use a pruning knife on the stalks. However, chain saws are the tool of choice for frond removals on most species and can produce an attractive appearance with the cut frond bases. However, the chain saw may be prone to clogging from palm fibers. Enlarged chain housings help alleviate this problem.
The palm trunk itself requires no pruning, and you should never disturb the apical bud, which is hidden within the emerging leaves. Most palms only possess one apical bud, and the tree will die if it is lost. Clumping palms with multiple trunks occasionally may need containment. If so, remove entire trunks to their base. Stubbing a trunk will not result in any new shoot production.
Some palms, such as coconut palms, require fruit removal for obvious safety reasons. This may be necessary as often as every few months.
SPECIALIZED PRUNING TECHNIQUES
• Shearing and hedging. Shearing provides a formal or well-defined shape to shrubs and hedges. Shearing requires either hand shears or powered shears, the latter being preferred for large jobs.
After a hedge has been planted, shear off the top one-third of each season’s growth until the plants reach the desired size. This shearing will prompt the plants to branch and fill in more quickly.
Once the hedge reaches maturity, shear off nearly all of the new growth two or three times a year, as needed. However, to maintain fresh foliage and good density, you’ll need to retain 0.25 to 0.50 inch of the new growth each time you shear. This means that the hedge will gradually increase in size. Therefore, you must periodically perform severe pruning to reduce the size of the hedge. Species tolerant of hedging generally recover well from such treatment. Do this just before new growth occurs, such as in early spring, to minimize the length of time the hedge is bare.
The top of a hedge should be slightly narrower than its base. This allows light to more effectively reach the lower branches and prevent them from dying out (see Figure 11, 85).
Irregular or curved shapes require the pruner to have some experience to produce the desired result. Practice, patience and a steady hand are the necessary ingredients. Squares, rectangles or long, straight hedges are somewhat easier to prune because you can rig reference lines to guide your cut. Simply run twine between two stakes at the level you wish to make the cut, and use the twine as a guide. Be careful not to entangle the line. For even greater precision, use a line level to ensure the cut is even and level. Use long sweeping strokes as you shear hedges with a power trimmer.
• Pollarding. Pollarding (see Figure 12, above) is a unique type of annual pruning that can help the landscape manager meet the aesthetic and size-constraint objectives of a landscape. Although it is a high-maintenance procedure, pollarding allows you to save and maintain valuable landscape trees at a small to medium size indefinitely with little loss of health or structural integrity. Other tree-crown reduction techniques, depending on the tree species and the size of branches you remove, may initiate structural problems that can lead to catastrophic failure in storms or under ice glazing.
To begin a pollard, make the first cuts at a twig or branch junction where the side branch is at least one-third the diameter of the stem you’re cutting (see Figure 12, above). By the next year, dormant and adventitious growing points usually begin to grow close to the pruning wound. You then can prune off the remaining branch or twig that extends past the point from which new shoots are growing (see Figure 13, above right). Also remove sprouts that begin growing anywhere else in the tree. At the branch or twig tip, remove most of the sprouts but leave one or two until the following year. Be sure to avoid cutting into the shoot collar at its base. Pollarding has now begun.
Over time, annual pollarding will result in the buildup of a head or knot at the pruned end of the branch. This swollen clump, composed of the structural and defensive collar areas of many pruned shoots, is the characteristic feature of a polled tree. Never cut into or behind this swollen area of current and old shoot collars. Nor should you leave shoot stubs. In other words, proper pruning practices still apply to pollarding.
The age of the shoot you choose to pollard is critical to developing a structurally sound and healthy polled tree. One- and 2-year-old shoots react well to pollarding. Thus, to minimize disease and decay, prune the youngest wood possible and maximize the ability of the tree to react to wounding by implementing a health-maintenance program. Pollard trees annually once begun.
If possible, start pollarding when trees are young. Because pollarding is highly stressful and stunting to a young tree, select good-quality trees growing on good sites for best success. Allow young trees to become established at their sites for at least 3 to 5 years before initiating a pollarding program. For best results, a tree should be no more than 2 to 5 inches in diameter with a large proportion of its height in living branches. Initiate pollarding on the youngest branches possible.
Remember, pollarding should keep a tree the same size for its entire life. Therefore, you should carefully consider every pruning cut from the first heading or crown-reduction
cut. You must establish proper height from the start. Young trees you have trained to the required height and form from the beginning will perform better than retrofitted mature trees. Failure to continue pollarding, once begun, leads to tree loss.
• Espaliers, pleaching and topiaries. An espalier consists of a branch framework trained to occupy a vertical plane, usually on some sort of trellis (see Figure 14, opposite page). Pleaching consists of weaving or intertwining branches to form various configurations, often that arch or otherwise overhang. These rather artistic forms of training require a great deal of attention. They necessitate extensive pinching and tying of branches to strong supports, such as a wood or wire trellis. Eventually, these plants may or may not be self supporting, depending on their structure and the type of plant.
Topiaries are plants you shear to attain specific shapes or designs that mimic animals, symbols or other shapes. Topiaries often use wire to hold branches in position or as a framework for vining plants. Shearing topiaries is not fundamentally different from other types of shearing, but it requires skill and experience. Consult references dealing with these specialized types of pruning for more detailed information.
Quality tools are necessary for good pruning, and you must maintain your tools properly for them to remain useful. Several factors influence your choice of pruning tools for a particular job: branch size, hardness of wood, height above ground and so on. Landscape professionals usually possess a variety of shears and saws for different situations (see Figure 15, page 88). The basic pruning tools include:
• Hand shears. Hand shears are designed for light pruning of branches up to 0.75 inch in diameter. Many grounds-care professionals routinely wear a leather belt and holster so that their hand shears are available for on-the-spot use for removal of small branches, deadheading and many other tasks.
Two basic types of hand shears exist: anvil-type shears and hook-and-blade shears. Anvil shears—also called snap-cut pruners—possess a sharp blade that cuts against a broad, grooved surface—the anvil. Hook-and-blade shears—sometimes called draw-cut or bypass shears—are the more commonly used of the two types and employ a scissors-type action to make cuts. Many professionals feel that hook-and-blade shears produce cleaner cuts with more precision. Both types are available in a variety of sizes, and styles are available for specialized tasks such as pruning miniature plants.
Hand shears vary in price and quality, but you will find that high-quality shears usually are worth the cost. They produce cleaner cuts, and they are more durable as well. Further, you usually can obtain replacement parts if they break.
Ratchet shears use a special mechanism to increase leverage,
reducing the force you must apply to make the cut. This may be of use to those with weak grips, but ratchet shears are not in widespread use among professionals because they tend to be less durable than conventional shears.
• Lopping shears. Sometimes simply called loppers, these two-handed shears are another of the basic tools of the landscape professional. The longer handles extend the pruner’s reach and allow you greater leverage for cutting larger branches. Loppers range in length up to 36 inches or more.
Similar to hand shears, hook-and-blade and anvil types are available, but the latter is preferred for professional use. Handles are made from steel, aluminum, fiberglass or wood. Although wood is perhaps most popular, the other materials have advantages as well. In particular, they are resistant to breaking. However, you can replace wooden handles if they break, and their flexibility and light weight make them easy to use. Thus, your choice of material for lopper handles mainly is a matter of personal preference. Rubber bumpers are a feature that greatly increases user comfort. Some manufacturers employ gear mechanisms that increase the cutting force of the shears, allowing you to cut harder wood or larger diameter branches.
• Pole pruners. Pole pruners consist of a pruning head and an extension pole. The head combines a saw blade and cutting shears the pruner operates with a pull rope. Some units allow you to replace the head with a large saw blade for cutting bigger limbs. The pole may be a single, rigid unit, but more often consists of telescoping sections that provide various working lengths up to 18 feet on the longer units. Poles usually consist of aluminum, but fiberglass and wood units are available, and these are preferable for work near power lines. Electrical lines pose a grave risk to workers using aluminum pole pruners.
Whenever you use a pole pruner, use caution. Limbs dropping from above are dangerous, and falling sawdust and other debris can cause eye damage.
• Pruning saws. A wide variety of pruning saws exists. Many are specialized for a particular type of job, and others are designed for more general use. Some saws cut on the pull stroke (useful for typical pruning on living wood), some on the push stroke (such as a tree-surgery saw used for heavy work on large branches), and some cut both directions.
Additionally, the size and number of teeth vary. Saws with smaller and more numerous teeth are suitable for smaller branches, or dead or hard wood. Two-edged saws have large teeth on one side of the blade and small teeth on the other (which poses the risk of accidentally cutting into desirable branches during use). Speed saws with raker teeth replace every fifth tooth with a slot or a raker to prevent jamming from sawdust on large cuts. A speed saw with lance teeth is recommended for large deadwood. Saw blades are cut from steel, and many have a non-stick coating to resist rusting and reduce friction.
Aside from the configuration of the saw teeth, pruning saws come in many designs. Curved saws with rigid handles are common, as are folding saws. Folding saws may require a screwdriver for tightening or they may use a wingnut. A disadvantage of folding saws is that the blade can work loose and cause the saw to collapse during use.
Bow saws are efficient for large branches but awkward in tight spaces. Thus, they are more appropriate for firewood
cutting than everyday pruning.
• Chain saws. Chain saws employ saw chains on a cutting bar and usually are powered by a gasoline engine (electric models are available as well). Chain saws are indispensable for cutting larger limbs. They are fast and less tiring than handsaw pruning. However, because of their size, weight and configuration, there is a limit to the cutting precision chain saws can provide. Further, pruners need to exercise great caution when using these tools—chain saw accidents cause many injuries each year. Thus, although chain saws are tremendous labor savers, avoid the temptation to use chain saws when a hand saw would produce a better, safer cut without undue effort. Always wear proper safety equipment when using chain saws—chaps, gloves, a helmet, boots, and ear and eye protection.
• Hedge shears. For pruning hedges or shrubs to a formal shape, you need hedge shears. Hand-powered hedge shears use two sharpened, broad blades that move with a scissors action to produce an even, flat cut. Many models also possess a limb notch for cutting slightly larger branches you may encounter while shearing. Handles range in length from about 10 inches to 2 feet or more for extended reach. Rubber shock absorbers increase user comfort.
Hedge shears powered by electricity and gasoline engines
are widely available. These employ an oscillating sickle bar with sharpened teeth that produces shearing action as it moves back and forth past the teeth of a stationary
bar. Gasoline-powered shears are preferred for large jobs and professional use because of their speed, power and portability compared to electric units. However,
electric units offer the advantage of low noise and therefore also have a place in professional use when you must keep noise to minimum.
• Tool maintenance. All pruning tools require some maintenance. Sharpening is the most common upkeep procedure you’ll need to perform. Sharp tools are far more effective than dull, neglected pruners so this is a matter that needs periodic attention. Sharpening is a relatively simple matter for shearing tools, which you can hone with a file and a whet stone. However, sharpening saws requires some skill and precision. If you are not experienced at sharpening saws, it is better to leave this task to a professional.
A coating of diesel oil, lubricant or other rust-inhibiting product prevents rust from forming on pruning tools. Apply such materials periodically to metal parts prone to rusting.
Most shearing-type tools have adjustments (screws or nuts) that control how close the blades pass to one another. If the adjustment is too loose and the gap between blades (or the blade and anvil) too large, wood will wedge between the hook and the blade during cutting. This causes slight bends in the metal and can render pruners nearly worthless. Thus, this is a factor that requires close, frequent attention.
Pruning involves some of the most potentially hazardous situations in the landscape-maintenance field. Accidents with chain saws and pruning shears are common and, all too often, tragic. Even small shears can sever fingers, and chain saws pose an obvious and potentially lethal hazard. Eye injuries frequently occur when sawdust or other foreign material falls into the pruner’s eyes. Receive proper training before using a chain saw or other power equipment. Gloves and eye protection always are a necessity when pruning. When you use power equipment such as chain saws or power hedge shears, ear protection, a hard hat and chaps also are necessary.
Electrical lines are a common hazard for tree pruners. Never use a metal pole pruner near power lines, and exercise common sense to avoid any possibility of electrocution. Remember, electricity can arc from lines—you do not actually have to touch them. Pruning near utility lines is a job best left to those experienced and equipped for this type of pruning.
Climbing trees also is a dangerous activity. If you do not have the proper training to climb trees, leave the job to someone who does, or use a hydraulic lift. Using ropes and other special climbing equipment takes experience and skill. However, these are necessary to avoid the damage of climbing spikes, an inexcusable practice harmful to trees.