Today a customer asked me this question, “We will want the trimming done, but don’t have a date yet. It depends on the progress with the construction. What are the ideal dates for trimming?”
What are the ideal dates for trimming?”
February 2, 2010
Ideal Time to Prune Trees & the Oak Wilt Pruning Season
April 25, 2009
Creative tree trimming, the rules don’t always apply.
Creative tree trimming, the rules don’t always apply.
Most guidelines for tree pruning are built around the idea that all trees already have good health/structural-integrity and have good growing conditions. Well, let me tell you this is not normally the case. Many tree trimming calls I go on here in Austin, Texas require creative techniques to help the tree fit inside its urban environment. The main topic I really want to discuss here is tree topping.
The standard rule for this is don’t do it. Tree topping is usually not a good tree trimming technique. We’re talking about cutting the ends off the branches of the tree. I’m 100% positive that trees don’t grow limbs so we can have something to cut, and I’m 100% positive that the leaves on the ends of those branches are making food for the tree. But, there are some situations where the tree topping technique can be used in an appropriate manner. Let’s look at “vista pruning.” Literally translated as view pruning, the goal of this is to improve a scenic view. You’d have to live in the hill country to understand this. Many people will spend half of their life-savings for a beautiful house on the side of the tallest hill over looking a beautiful canyon, and within a few years the backyard trees have grown up and block the entire view. Can we cut the tops of the branches down in height without ruining the tree?
Let me give you one little factoid about the native trees living on the hill country slopes: their average life expectancy is about 40 years. Trees growing on the side of steep rocky slopes have difficult time rooting solidly. I would argue that pruning the top of a tree down in height accomplishes two things here. One, by reducing the height of the tree you are reducing its over all weight, and, therefore, reducing gravity’s efforts to pull it down the hillside. Secondly, maintaining limited canopy size reduces strain on the root system to find water and nutrients, two commodities in short supply on the side of a hill. I do believe that you can functionally maintain the height of a tree on a hillside to improve your view.
Please don’t take this too far. I’m not advocating that all trees on hill sides be topped. I’m just saying that it can be done in a manner that would allow the tree to live its normal life expectancy. If you are going to do some vista-pruning, do so cautiously; leave as much foliage on the tree as possible.
For info on proper pruning techniques, please see my tree trimming series.
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April 15, 2009
Tree Pruning: volume 4, When to Prune Trees
“When is the best time to prune trees?” This is one of the most common questions I get asked. The truth is there aren’t many timing concerns for tree pruning in the Austin area. Let’s start with the most common mistake I hear people make about when to prune trees in Austin, Texas.
You cannot adapt rules from other climates to Austin. If you go to the north east part of the country there are imporant guidelines. There, the dormant season is long and the trees are much taller. This means that bigger trees have less time to get all their growth cycles done. During the spring and fall months, trees in this area have intense sap flows. Pruning during these times will lead to bleeding wounds which leads to every insect and disease in the book. In Austin we don’t have this problem. Our seasons tend to run together; you can prune any time and not get bleeding wounds. Except with American Elms, these trees will produce bleeding wounds regardless of when you prune them.
The only concerns we have in Austin, Texas for when to prune trees is geared specifically around one tree diesase, oak wilt. There is one beetle know to spread the disease and it is active for only a few weeks during the spring. The timing of activity varies from year to year but it is generally always between March and May. The Texas Forest Service recommends you avoid wounding trees during this time. There adoption of this rule is based on concerns of homeowners capacity to understand and remember intricacies of the disease spread. If you are working with a professional who makes proper cuts and treats wounds, there is no risk of disease in pruning wounds.
In conclusion, the answer of “when to prune trees in Austin, Texas” can be answered by two sentances: If you hire a professional, knowledgeable arborist, you can prune any time. If you are doing the pruning yourself, avoid pruning between March and May.
Tree Pruning: volume 2, What to Prune on Trees
Identifying what limbs to cut can be one of the most difficult parts of pruning a tree. I discussed the three reason’s why to prune trees in volume 1 of my pruning series: for tree health, cosmetics and structural integrity. However, many times these different reasons would lead you determine that different limbs need to be pruned. Balancing these priorities is where experience and an artistic eye really comes into play. Different people will often come to different conclusions. While weighing your priorities for pruning there are a few general rules you can follow to help error on the side of benefit for the tree.
The first general rule is to always avoid removing large limbs when you can accomplish your goals by removing multiple smaller limbs. Trees do not have an efficient system for healing wounds larger than 3” or 4” in diameter. These larger pruning wounds can take several years to callous over and lead to more extensive decay in the tree. While this is usually not a short term problem for the tree, removing large limbs will chisel years off the tree’s total life expectancy.
Remove any dead limbs. Dead wood is the food source for mother nature’s natural decay fungi. Removing deadwood both removes decay food sources and facilitates wound healing. In the winter months, identifying dead limbs can be tricky. A good arborist can easily tell the difference between a limb with dormant buds and a dead limb. For the average Joe I recommend you do your pruning during the spring and summer months when it is easy to tell which tree branches need to be pruned out.
Pruning soft wooded trees such as ash or pecan to thin the canopy will help improve the tree’s structural integrity. This reduces the overall weight load of the canopy and reduces the wind-sail effect since there will be fewer leaves catching the wind. For an otherwise healthy tree, canopy thinning should remove about 5-10% of the trees total canopy. This should be done by removing many ½” to 1 ½” limbs symmetrically throughout the extremities of the canopy.
These are some basic guidelines. Unhealthy trees, trees with mistletoe and trees in Oak Wilt sensitive areas are complicated even further.
Tree Pruning: volume 1, Why to Prune Trees in Austin, TX
Tree Pruning in Austin is complicated by many factors. There are several subjects that should be examined such as when to prune, what to prune and how to prune. In this article I’m going to focus on why to prune trees and what factors relate specifically to Austin. Health, cosmetics and safety make up the meat of the formula I use to understand why you should prune your trees.
Let’s start with pruning for tree health. Most everybody loves trees; we want them to live long and prosper. Just like your doctor can prescribe you exercises and eating habits that will help you live longer, tree pruning can add to the overall life expectancy of a tree; as long as the pruning is done right. In Austin, we have to worry about Oak Wilt. Pruning your trees properly can reduce your chances of contracting oak wilt, and conversely, failing to take precautions can cause unnecessary exposure to the deadly fungus. Look at my Oak Wilt articles for details on this. Pruning a tree to remove dead limbs helps the tree heal the wound and limits overall stem decay in the tree. The motivating factor to prune your trees isn’t always to improve the health of the tree, sometimes (maybe even most of the time), trees are simply in the way and we need to remove limbs that are too close to the house or in the street. In these scenarios the idea is to prune the tree in a manner that offers the least damage to tree health.
Moving on, the number one reason to not let uncle Bob prune your tree is cosmetics; the amputated-arm-look is not in. And, regardless how good your landscape designer is he can’t recreate a the majesty of well manicured, mature shade tree. Tree pruning is an art mastered only by years of experience. Aside from the aesthetics of a tree, one also has to consider how the tree impacts the surrounding landscape. Pruning may be needed to allow sunlight for the turf, trees may be over-crowded by ambitious landscaping and need to be shaped and thinned, or center piece trees may need sculpting to really set off the look of the landscape. Or, for the true naturalist, tree pruning should be done in a matter that improves the health of the tree without compromising the natural look.
One natural thing about trees that most people over look is that trees naturally fall apart as they age. Pruning is one of the tools you have to help prevent your favorite tree from crashing into your house. Structural integrity might be the most important thing your arborist should be looking for. Most tree pruning guidelines are built around this subject. Usually when you see failed tree, be it from a storm or a random summer afternoon, there is usually some defect that led to the disaster. The best pruners have an eye for included bark and decay. Cabling and bracing are other techniques that can be used in conjunction with pruning to improve the safety of your tree.
I think this subject is sufficiently over-complicated at this point. If you’re the type that chooses to hire professionals to do things for you, you should have enough ammunition to do your interviews. For the do-it-yourself guy/gal keep reading. This is an introduction to the subjects surrounding tree pruning; you have a lot of reading ahead of you. We still need to cover what to prune, how to prune and when to prune.
April 14, 2009
Tree Pruning: volume 3, How to Prune Trees
How to prune trees? The easiest way to prune trees, obviously, is to hire somebody. If your budget or some other factor is preventing this there are a few things you should know to help you on your mission. By now I expect you have read the first three volumes of this 4 volume tree pruning series. If you haven’t read the other articles yet, please do before beginning your pruning session. There is a lot more to know than just how to prune a tree.
Before getting into the nuts and bolts here I want to share with you an observation I’ve made from my many years in the business. Ladders cause more accidents than any other single factor in the tree care business. To safely prune a limb while working on a ladder you need: one hand for the ladder, one hand for the limb the ladder is leaning on, one hand for the limb you are cutting and one hand for your cutting tool. Even if you have a tail you’ll be one hand short. And since your ladder must be positioned close to the limb you need to cut, this means the limb is going to fall near your ladder and very possibly bring your aerial support system to the ground. If you find yourself needing a ladder to do the job, STOP, it’s not worth it (or, at least call your insurance broker to make sure your health and life insurance policies are in good standing).
The first thing you’ll need to do is make sure you have the tools for the job. I recommend keeping the following tools if you are going to be an avid pruner: hand pruners, loppers, extendible pole saw and extendible pole loppers. An extension pole pruner combo is available that has both a saw and loppers in one tool. Chain saws are commonly used, but only go here if you really know how to handle them. There are a few issues with chain saws. One, if you don’t use them regularly they don’t want to run. Second, they are very dangerous. Even with the so called safety features you can easily cause yourself a major injury. Finally, it’s not easy to keep the chain in cutting condition. One nick of a rock or failing to cut in a straight line will quickly cause damage to your chain or bar. You can easily spend more money on chain saw maintenance than it would have cost you to hire somebody. Regarding your hand pruners and loppers, you’ll have a choice between two styles: anvil or by-pass. By-pass pruners work like scissors and anvil pruners come together like pliers only with one side having a knife and the other side being flat. The general consensus is that by-pass tools make a cleaner cut. But, by-pass pruners are easily bent out of alignment and once this happens they basically won’t cut at all. Anvil pruners are less prune to damage and when they are damaged they’ll still cut. From experience, I can tell you that the most important factor really is that you keep your pruners sharp. Have them sharpened at least once a year if you don’t know how to do it yourself.
The other thing you need to know about how to prune trees is how to make a proper cut. Technically written, a proper cut should be made just outside the branch bark ridge and leave the branch collar intact. Let me translate this into understandable terms for you. Let’s start by looking at the branch you want to cut off. Follow the branch all the way back to where it connects with its parent stem. Where it connects you will see on the top side of the joint, a line or crack that separates the limb you want to cut from the parent stem. DO NOT CROSS THIS LINE. Anything beyond this line (or crack) is tissue of the parent stem, you don’t want to damage the parent stem. So, starting just outside the line, cut perpendicular to the limb you are removing. Cutting perfectly perpendicular will cause the wound you make to be circular in shape. If you cut in an angle the wound will be oval instead of circular which means the wound will have larger surface area and will take the tree longer to callous over. If you are cutting a large limb make your first cut approximately 12” out from where your final cut will be. Often when removing large limbs, after cutting halfway through the limb, the limb will begin to crack and fall before you finish making your cut. This causes the bark to tear down the trunk and we don’t want this. When making your first cut 12” out from where your final cut will be, begin by making a small cut on the underside approximately ¼ through the branch. Doing this will cause the limb to snap off instead
I'm Keith Brown, owner of Austin Tree Experts. This is my repository of tree knowledge. I hope you find what you are looking for. Let me know if you don't.
