How to Prune a Palm Tree

Including common mistakes made by Homeowners and Pros alike

Now, I must admit I have trouble using the word “pros” and “pruning mistakes” in the same sentence.  In my mind, a professional tree service, tree trimming company, arborist or whatever label a business uses to describe itself, should be following ANSI pruning standards.  If they do, they won’t be making mistakes. However, many do not follow ANSI guidelines.- and it’s the palm tree and its owner who suffer the consequences. ANSI, the American National Standards Institute, is a collection of standards for many trades and professions, including arboriculture (tree care).  These standards are determined by a panel of industry experts which is assembled every few years to review and make updates to the standards based on their combined experience, observations, and the latest research.  For arboriculture, that research is conducted mostly by state universities in cooperation with their state’s Department of Agriculture.  In Florida, this would be the University of Florida, although research conducted in other states is often also relevant in Florida.  Input is also taken from the United States Fish & Wildlife Service (USFWS), Division of Forestry, as well as state foresters and practicing arborist..  Together, these industry professionals and government experts sit down and update the ANSI standards for arboriculture so that other industry practitioners can have clear guidance on which tree pruning practices are recommended, not recommended, and downright discouraged.  Out of the ANSI standards, the International Society of Arboriculture (ISA) and the Tree Care Industry Association (TCIA) publish best practices manuals which are made available to practitioners at a very reasonable cost.  So, what does this body of knowledge tell us about pruning trees? Read on, and we will look at some specific examples.

How to Prune a Palm Tree

First of all, let’s clear the air on the subject of pruning palm trees. Unlike dicotyledonous angiosperms (trees with branches, other than conifers), there is no health benefit heaped onto a palm tree through pruning. While branched trees can benefit immensely from structural pruning during their first 30 years or so of life, and live much longer as a result, there is no reason to prune a palm tree other than aesthetics and safety. The aesthetics part I’m sure you already understand; we have been taught (whether we realize it or not) to like neat, green, tidy looking plants. Yellow leaves, we presume, indicate a health problem, and brown leaves are just plain ugly. Well, everything we have been taught, or assumed, in that last sentence is not necessarily accurate. Let’s expand on these further for clarification.

Mistake #1: Over pruning – By far the most common pruning mistake on palm trees is removing too many fronds (leaves). Every palm tree has a carrying capacity of a certain number of fronds, that is, how many fronds the plant can support at one time. This number can vary between species, and within plants of the same species carrying capacity can be affected by plant age, soil conditions, including nutrition/fertility, water availability. good drainage, etc. Other factors that can affect carrying capacity are stressors, such as poor light, insect infestation, drought, fungal infections, excessive heat (hot parking lots, for example), cold stress, and so on. So, when a palm tree grows a new frond, it necessarily gives one up at the bottom to make room in the system for the new one. Where over-pruning comes in is when we prune a frond that is not yet brown and dead. You see, that yellow frond that looks sickly is actually being sacrificed for the benefit of the new frond. The palm tree is actively moving micronutrients from that sacrificial frond to the new one. If that yellowing frond is removed, valuable trace elements are robbed from the tree. When this is done repeatedly over years of abuse under the guise of tree care, the long-term effect is a palm tree that becomes deficient in one or more micronutrients, unless they occur in the soil in great abundance. Here in Florida, that is a rare situation, outside of a managed soil fertilization program. In other words, if you just HAVE to remove those yellow fronds before you pull your hair out, at least do your palm tree the service of replacing that lost nutrition with a little fertilizer around the root zone. The best practice is to remove only dead, brown fronds. If yellowing or green fronds are to be removed for some reason, such as clearance, in NO CASE should fronds be removed that originate above the horizontal from the trunk. In other words, if the base of the frond is pointing at all in an upward direction, it should be left on the tree. Removing fronds above the horizontal starves the tree of energy needed for new growth- it would be like having a solar system installed on your roof, and then disconnecting half of the panels. Why would you do such a thing? Does that sound like a good idea? Of course not.

The second reason not to over prune palm trees is that it leaves the apical meristem, or growth bud, exposed and less protected. I remember 25 years or so ago apprenticing under a friend who ran a lawn care and tree business, and he taught me to do “hurricane cuts” on palm trees prior to hurricane season. Back then, it was believed that reducing the wind resistance of the fronds was good for the tree. Since then, however, research has been conducted comparing coconut palms that were “hurricane cut” and others that were not, and how they performed in hurricane force winds. As it turns out, the “hurricane cut ” trees suffered a much higher rate of damage and mortality vs. the trees that were not pruned. One reason was the lack of protection from flying debris; the other was that the younger fronds, being less sturdy than an older, mature frond, was more likely to tear off without the older fronds in place to protect it, and the growth bud was often damaged by the tearing. As it turns out, the bases of the fronds left intact help to protect the bud. Do not over-prune your palm trees, I beg you. If you are hiring the job to a professional, check their website for pictures of their work. The following pictures illustrate correct and incorrect pruning of palm trees, Whether you tackle the job yourself or hire it out, make sure that whoever does the work knows the difference. One word on inflorescence- the flower stalks on a palm tree- they can be removed at any time, even while still enclosed in their sheath, without harm to the tree- so long as the saw does not contact the bud.

More over pruned palm trees
The company that did this job over-pruned these trees. The brown fronds should be removed, but notice that the remaining fronds are well above horizontal as they leave the now exposed growth bud. Notice, too, the narrowing at the top- you should not be able to see this part of the tree. These are now very vulnerable to attack from insects and fungal diseases, as well as susceptible to storm damage from high winds.
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The Mexican fan palms in the fore have not been pruned yet; the ones in the background are properly pruned.

Now, I want to make it clear that I am in no way attacking other tree companies for over-pruning trees. It would please me very much if they read this article, or the ANSI A300 standards for pruning, or any of a number of up to date books and learned how to do a better job. These are by and large honest, hard-working people. Usually the reasoning behind over-pruning a palm tree, besides ignorance of the more recent research, is the belief that by removing more fronds, the tree won’t need to be pruned again so soon. They’re actually trying to do a great job and save you some money doing it. However, although this sounds just as logical as “if I cut my hair twice as short, I can go longer until I need another haircut”, palm trees are different. In reality, what happens after a palm tree has been over-pruned is that initially it is shocked and stressed by the loss of energy-providing greenery. It responds to this loss of greenery by- you guessed it- making new fronds. In fact, that palm tree will grow new fronds at an accelerated rate, if conditions permit, to get back to its natural carrying capacity. So in the end, you didn’t save any money by over-pruning the tree. You actually paid more, because whereas perhaps only 4 fronds needed to be removed, 20 fronds were- and you are paying for time. Additionally, the burst of growth causes the tree to grow taller a little faster, which causes narrowing of the trunk below the growth bud, making the tree weak. (healthy palm trees, with a few exceptions, have the same trunk diameter for their entire height). This problem is so rampant that some cities are cracking down. Bradenton, for example, now has an ordinance on the books that tree owners can be fined quite heavily for having their trees over-pruned, and there is a system in place by which they encourage complaints to be filed against offenders, anonymously if desired. The city’s website warns to do your research- so you are in the right place. If you read and understand the articles here about pruning, and you make sure that whoever you hire to do the work understands ANSI A300 standards, and follows them, you will be fine. Fail this, and you could get fined. I would like to help you avoid such an unfortunate circumstance.

Another example of over-pruning is with the Sago palm, which actually is not a true palm at all, but a cycad- one of the oldest living taxon of plants on earth. They grow extremely slowly, and so tend to be quite expensive for their size- yet in spite of this, they are sometimes seen over-pruned to the point where they look like a pineapple on a stick. Like palm trees, Sagos, or cycads, need those yellowing fronds, and for the same reasons should not be pruned past the horizontal. Most large specimens are seen at posh resort hotels with big startup budgets, yet it still amazes me that anyone would risk the health of a tree that might cost upwards of $20,000 to replace by over-pruning it because they think it looks “cool”. I don’t know about you, but that’s not how I run MY business.

Anyway, don’t over-prune your palms or cycads, and they will grow at a proper, more natural, healthy rate- it’s the right thing to do for so many reasons. Now that you understand what to prune, and what not to, let’s talk about the how part of pruning palm trees.

Proper tools: This brings up the second most common mistake made in pruning palm trees, the use of chainsaw-type pole pruners. These should not be used on species of palm trees which are susceptible to fusariam wilt (a common fungal disease, also notorious for killing tomato plants), which, frankly, is a long list. It’s best just to play it safe, and not prune any palm tree with a chainsaw. They have become very popular for their time-saving benefits, but the problem with them is that it is very easy to spread fungal diseases from one tree to another. The traditional flat-bladed pole should be used instead, and it should be sanitized between trees. Bleach water solution (10{ac50515e39d6919d21eb74dc04197560ad93c8ec02983c4c116f059a37f908c3} bleach and 90{ac50515e39d6919d21eb74dc04197560ad93c8ec02983c4c116f059a37f908c3} water) is recommended; to save time I will sometimes use germicidal wipes to clean the blade of the saw between trees. In all cases the blade of the saw is removed and soaked in bleach solution before being used on another property. As a side benefit, the saw stays clean, which helps it cut easier. Since there is no feasible way to sanitize a chainsaw, they should not be used on palm trees unless only strictly dead fronds are being removed, and even then there is still a mild risk of spreading fungal spores from the lubricating oil that sprays off the chain. The pole saw cuts on the pull stroke, which combined with its curved blade makes it quite easy to use. You simply adjust the length to where you can rest the blade of the saw on the base of the frond to be removed, and pull the handle. Do not force the saw into the cut, as the curved blade will do that for you. On larger fronds it may take several strokes to sever the frond. On trees such as date palms and silver fan palms, which have a very large frond base, it is best to first cut on the bottom of the frond stem (petiole), then on the top to remove the frond, with a final cut being made closer to the trunk without the weight of the frond. This 3-cut technique avoids causing damage to the tree from the frond falling and tearing the petiole while it is being cut., which can cause injury to the tree. On some palm trees with slender frond bases, such as Pygmy Date Palm (Pheonix Robelleni), the lopper may be used instead of the saw. Simply fold the saw out of the way (or it can be removed), hang the lopper hook over the frond to be cut, and pull the rope to cut the frond.

Best practice for palm trees is to use a pull-stroke saw, not a chainsaw. The saw blade should be sanitized between trees to prevent spread of diseases, most of which prove fatal to the tree.

Hopefully, this article has given you what you need to prune your palm tree, if you choose to do it yourself, or what to look for and what questions to ask if you are going to hire it out. For more information, questions, etc., please feel free to contact me at Tree Wise Guys, and I will answer you as soon as I can. We don’t do mailing lists, nor share your information with anyone else.

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