Ever wonder why you’re paying someone to do something so seemingly simple? Couldn’t anyone do it? Well, sure, with the right tools, skills & knowledge. It isn’t rocket science, however, proper tree pruning does certainly have a base in biology, mixed with some aesthetics. There is much more to properly trimming a tree than most people realize. Here is a little help in deciphering the jargon that you’ll hear in the industry of tree care, so that you can better understand that various needs of trees in the urban setting. Having at least a basic understanding of the terminology your Certified Arborist uses will decrease misunderstanding & help to achieve precisely what is desired or necessary. Following are examples of some of the most common types of pruning that trees typically need, and, more importantly, a couple warnings of what NOT to do to a tree.
The definition of “crown-thinning” is the removal of a conservative amount of secondary branches (not any major limbs) evenly throughout a tree — typically 25-30% of the canopy. A more aggressive crown-thin can sometimes be justified for only the hardiest of tree varieties. For your average shade tree, crown-thinning is the most basic yet important type of pruning. How frequently this should be done ranges from about twice per year to once every few years, depending on the tree variety and the individual tree. The best way to judge whether a tree is due for a crown-thin is to look up into the canopy — rather, to look THROUGH the canopy — to see how much of the sky is visible through the foliage of the tree. If it is so dense that one cannot hardly see any of the sky beyond the tree, crown-thinning is definitely recommended. WHY? Because if you cannot easily see through a tree’s canopy, then there will be a lot of resistance to wind, just like the sail on a boat. This is mainly a problem if a storm comes through, and then all one can do is hope for the best. The Arizona monsoon season is known to be accompanied by microbursts that unpredictably strike certain areas with particularly strong winds. Proactive tree care will avoid a canopy that is overly dense, so as to minimize the chances of broken limbs or even loss of the entire tree. If a tree’s foliage is growing very densely, there will also likely be crossing branches which will tend to rub against each other with normal shifting (as caused by wind or other forces), and as they grow the limbs will cause wounds at points of contact that worsen over time. A good Certified Arborist will be mindful of crossing branches — or branches that will eventually cross — while performing a crown-thin. Other more minor issues that a basic crown-thin will help with is shade. With more sunlight allowed through to the grass or other plants growing under a large shade tree, you can hope for a healthier lawn or shrubs that would otherwise be too shaded.
Crown-reduction is the correct way to make or keep a tree smaller. Crown-reduction means shortening many of the secondary limbs around the outside of the canopy using proper reduction cuts. The best application of crown-reduction is when a tree has been planted in a small area. It isn’t uncommon for a sapling tree to be planted with little to no consideration given to how large it may eventually become — which varies depending on the species as well as environmental factors (such as watering and soil quality). Mindful planning of the potential sizes of various tree in a yard is tricky, and if mistakes have been made, crown-reduction can help with overcrowding in the yard. Some trees are kept small purely for artistic reasons as well. A bonsai tree is the extreme example of the growth, the size of a tree, being severely scaled back.
Similar to crown-reduction is structure clearance, which is reduction of foliage away from (or also raising over) buildings, power lines, sheds, fences, pools, or anything else where overgrowth may potentially cause property damage or inconvenience. Whether the concern is pests, pool filters, boundary fights with neighbors, or large limbs dropping onto the newly tiled roof, structure clearance will likely be needed on a regular basis for best results as the tree grows. The earlier a future conflict is foreseen, the easier it is to “train” a tree to grow a certain way (i.e. to promote vertical/horizontal growth, to stay clear of telephone lines, etc). A Certified Arborist can help save you money in the future by bringing such issues to your attention before they get harder to fix.
The main reason for crown-raising is simply for ease in moving around in the yard, such as applying mulch or fertilizer underneath the tree or mowing the lawn. This type of pruning is common over carports or to increase visibility of street signs, as regulated by the city.
To shape is to trim away limbs that extend much farther from the canopy than those around it. This is almost purely a matter of taste, and not actually necessary for the well-being of a tree. Often any sort of trimming performed by a Certified Arborist will also include artistic considerations, such as roundness, or an overall sense of ‘balance’ or symmetry. Just like the way you part your hair in the morning, it makes sense to more or less go along with what nature seems to want. Shaping is NOT to be confused with “hedging,” which ought only be done to bushes or hedges, if at all. Citrus is one example of a tree that needs little more than shaping, as they do best if kept looking like a large bush. This is because clearing out too much of the interior growth may overexpose the bark, and citrus are especially prone to sun scorch. If the skirt of a citrus tree is raised high enough to show the trunk, it will need to be painted. Likewise, if their canopies are not leafy and dense enough, other branches exposed to too much direct sunlight will need paint.
Crown-cleaning is simply removal of unsightly dead branches. Removal of deadwood is has both aesthetic value and safety considerations — dead branches are ugly, and they may eventually be shed (which is of course problematic for large limbs over homes, carports, or where people or pets often walk underneath). The most common time of year for crown-cleaning is during the Springtime after there have been hard frosts — ficus and sissoo are especially vulnerable to frost damage, as well as any tropical tree variety. For deciduous trees, it can be hard to determine what is dead and what is merely dormant during the Winter season; in the Spring and Summer months, after the trees have leaved out again, deadwood will be more apparent. Another way to tell dead from living is by scratching away some of the bark to see if it is green underneath (possible on ficus, bottle trees or other varieties with thin,waxy bark). For thin branches, pliability is an indication of being alive; if a twig does not easily bend but is so brittle that is snaps, it is dead. In cases where a tree has a lot of deadwood, a Certified Arborist can help you judge whether a tree is in a state of decline because of age or because of environmental factors (i.e. watering and soil quality). Sometimes measures can be taken to prevent further decline, such as fertilization or more consistent deep-watering. Otherwise, complete removal might be necessary for a tree that cannot be salvaged or is already completely dead.
Subordination corrects the specific problem of codominance. Codominant leaders, whether in multiple trunks or in major branches higher up, are called codominant because they are similar in diameter. The crotch between them will typically be V-shaped (instead of the ideal U-shape). The problem with a tight V-shaped crotch is that there may eventually be included bark at the union of the two codominant branches, which weakens the crotch until eventually each major leader grows heavier and heavier and they actually split apart. The larger the tree, the more danger the problem poses to the tree itself (as well as the people or animals living nearby). Codominant trunks with included bark is especially problematic in places where the splitting of a big, heavy portion of the tree could cause expensive damage to cars or homes, or injury to people or pets. If severe codominance has gone unnoticed or ignored too long, it may be irreversible or require drastic measures to avoid potential damage. Much like cancer, this and other structural flaws in a tree is not something that the layman will readily detect in early stages, but a Certified Arborist can often to catch such potential problems before they even develop. The sooner it is detected, the easier it is to remedy through subordination. Subordination of co-dominant leaders involves choosing one leader or the other to “take over” as the main trunk. Effective correction takes time, sometimes a number of years, because subordination utilizes the natural growth patterns of trees. Basically, the leader that has been chosen as dominant will be left mostly alone. The other leader will be subordinated using heavy thinning. Over time, this subordinated leader’s growth will be slowed, while the dominant leader will increase in diameter. The hoped-for end result is a healthy crotch where instead of a giant slingshot shape there is now a smaller branch growing from a larger trunk. If codominance with included bark is too severe to be corrected using subordination, other options include cabling, bracing, or removal of one of the major leaders (which would probably be drastic and leave ugly gaping holes in the look of the tree). Naturally, subordination would be preferable; thus the importance of catching problems before they are critical. If you aren’t sure, have a Certified Arborist look at the tree. This is their area of expertise and most will not charge anything for a consultation appointment.
A topping cut (sometimes called a “heading cut”) is arbitrary and does not take into consideration the way trees naturally grow. Only untrained, inexperienced, or unethical climbers will do this or topping. Topping cuts can have horrible consequences that are both ugly and potentially dangerous: it results in structural problems such as dieback or brushy sucker growth at the site of the topping cut. Certain tree varieties, wherever topped, tend to die die back to the nearest crotch, leaving ugly stubby ends of branches. Other tree varieties will try to ‘recover’ from the offensive topping cut, compensate for it, by sending out many small suckers that grow behind the face of the cut, surrounding it & extending beyond the stubby end. This will develop into an unsightly brushy appearance at the site of each topping cut. More troublesome than the way it looks is the compromise in structural integrity. Each of these tiny branches is very weakly attached to the topped branch it grows from. As the suckers grow into larger branches they tend to break because of their poor connection with the mother branch (the one that was topped).
The ONLY type of cut that should ever be made is called a “reduction cut.” With reduction cuts (whether for thinning, shaping, raising, reduction or removal of deadwood) the tree continues to grow in a normal & healthy fashion. A reduction cut is made close to (just after, or distal to) a crotch, so that there can be continuance of the growth of the tree branch. Without complete understanding of the way trees grow, just trust that reduction cuts are the accepted standard in proper tree care, and that topping cuts are bad.
Pollarding utilizes topping cuts for artistic effect, but it requires great skill & regular maintenance. It is not the same thing as topping a tree. For more information on pollarding, see this website: http://www.wildwillowdesign.com/2012/12/the-dos-and-donts-of-tree-pollarding/
This is an effort to undo the negative effects of topping cuts. With crown-restoration, the aim is to select one or two of the errant little suckers emerging behind the topping cut through which growth will continue; all the rest are removed. Over time, the branches chosen to remain will develop stronger attachments and eventually will no longer pose as great a threat of breaking. If crown-restoration is done effectively (the sooner the better), then hopefully, over a period of years perhaps, the tree can return to its pre-topping grandeur. Obviously, the best thing to do is to avoid topping trees; otherwise there redemption in crown-restoration.
This is most often seen in olive trees or ficus trees. This is when the major branches have been stripped of all their smaller secondary branches except at their tips. The result resembles a lion’s tail — long & thin, bushy only at the tips. Lion-taIling is not congruent with the natural growth patterns of trees, and is also quite ugly. The optimal taper of a tree’s branches should resemble a carrot’s classical shape. In a tree branch, this means that the diameter (thickness) is detracted from along its length by having smaller branches branching off from it. A tree that has been repeatedly lion-tailed is evenly slender all along its length, with a lot of weight only at the end. This stress causes breakage, which of course should be avoided.
If a property owner values having beautiful, healthy trees around, the appropriate type of trimming is a major aspect of maintaining them. Periodic assessment of your trees by a reputable Certified Arborist will save you money over the long run, since an experienced Certified Arborist will recognize structural problems before they worsen and become harder (or impossible) to correct. Having an trusted, experienced Certified Arborist help you help you determine what your trees need is the responsible, proactive way to avoid future problems and expenses.
Key Benefits of the Service
Preventative Maintenance will extend the life of your trees by ensuring the structural integrity and aesthetic value of each variety of tree. These are just some of the advantages of regular maintenance to your trees:
Properly shape the crown
Trim heavy foilage
Prevent crossing branches
Thin branches for less wind resistance
Removal of deadwood