The Root of Many Plant Problems in Central Ohio: Soil pH

By Walter Reins
ISA Certified Arborist
April 25, 2024​

You’ve probably heard the term pH. You may even think “I know this one - it means something is either acidic, neutral, or alkaline”, and that wouldn’t be wrong. But what does that mean and why does it matter? What determines the pH of soil, water, or even the human body? Like the periodic table of elements, pH may be something that reminds you of high school chemistry class, something you’ve filed away under the “when am I ever going to use this?” section of your brain, long ago forgotten and collecting dust ever since it was put there. While pH is far from being an endorphin-producing topic, it does significantly influence plant growth and overall health in your landscape. Let’s discuss the role that soil pH plays in nutrient availability, soil chemistry, and even microorganism activity, and why it matters for your plants.

pH and How It’s Influenced

pH stands for “potential of hydrogen”, and is a measure of the acidity or alkalinity of a solution, ranging from 0 to 14 with 7 being neutral. A value below 7 is considered acidic while a value above 7 is considered alkaline (or basic). This scale represents the concentration of hydrogen ions present, with acidic solutions having a greater number of ions and alkaline solutions having fewer ions. In soils, that concentration of hydrogen ions is influenced by things such as the parent rock material that originally formed the soil, human activity, climate, and the presence or lack of organic matter. In turn, the resulting pH will influence the availability of nutrients essential for plant growth, microbial activity that helps with nutrient absorption, and soil chemistry that influences the breakdown of soil particles into more usable forms. Of the influencing factors mentioned above, parent rock material and the presence or lack of organic matter often go hand in hand and are the most significant influencers in our central Ohio landscapes. Central Ohio largely consists of limestone bedrock, which naturally has a higher pH than what’s preferable for most plants. So you might ask “Well, how is it then that any plants can be healthy and thrive in central Ohio?”. The answer is organic matter. In an undisturbed, natural environment like the forest, years and years of organic matter have formed on top of the infamous “Ohio clay” subsoil that we encounter in our backyards. The source of this organic matter comes from falling leaves, dead branches and trees, and dying organisms just to name a few, that collect on the forest floor year after year, decade after decade. These are all things we tend to remove from our landscapes to keep them tidy, which results in a lack of organic matter formation over time. For more on how to address this topic, check out our Arbor Ed article “Leave those Leaves!”

Nutrient Availability

Chlorosis in a pin oak tree in Bexley, Ohio

pH influences the availability of essential nutrients in the soil by changing their level of solubility. This simply means that pH will determine whether or not these nutrients are in a form that can be absorbed by the tiny roots and roots hairs of plants. Most plants will prefer growing in soil with a pH range between 6-7, slightly acidic to neutral. When the pH is out of its optimal range for a particular plant (generally too high in central Ohio), the plant’s growth may slow, it may lose overall health and vigor, or conditions like chlorosis can develop because that plant isn’t getting the nutrients it needs to carry out essential functions for growth. Chlorosis, or yellowing of leaf tissue, is a very common condition in central Ohio and can be seen most often with trees like pin oak, red maple, white pine, and river birch. It’s interesting to note that these are trees that are either native to Ohio or an adjacent region. In their natural habitats where organic matter is abundant, soil pH is lower and nutrients are readily available for uptake. The parent material, derived from limestone and having higher pH levels, does not affect the trees since the absorbing roots are largely growing in the organic layer above it. In our backyards however, carpeted with lawn but cleared annually of leaves, higher pH levels can quickly cause issues even with otherwise healthy trees.

Chart showing availability of essential elements at various pH levels

Microbial Activity

pH affects the activity of microorganisms in the soil. These microorganisms are essential for plant health, helping plants to absorb certain nutrients, or aiding in the breakdown of organic matter into available forms for your plants. Certain fungi, bacteria, or insects that benefit a particular plant will naturally thrive in the same pH that is ideal for that plant. Encouraging the proper pH for your plants in turn helps to foster a healthier population of these important helpers in the soil. In the same way that our own bodies are influenced by the health of our gut bacteria, plants rely on microbial activity in the soil. Without it, they can struggle to carry out essential functions for proper growth and overall health.

Soil Chemistry

Similar to nutrient availability, pH can affect the chemistry of the soil and determine whether or not the available nutrients will be absorbed by roots. It also influences the composition of the soil, helping certain minerals to break down into smaller molecules, ultimately affecting the charge of soil particles and the ability for the soil to hold on to essential elements that could otherwise be removed from the soil. A good example of this would be a soil’s ability to retain certain nutrients by preventing them from getting washed out of the soil by irrigation or rainfall. Acidic soils tend to be better at retaining more of these charged nutrients. It's no coincidence then that most plants prefer acidic or slightly acidic soils, as the lower pH makes those soils richer in nutrients and more “user friendly” for plants.

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Soil pH plays a significant role in the overall health of trees, shrubs, and other plants in our landscape. A little bit of knowledge can go a long way in helping to understand the unique issues you may have in your central Ohio landscape. Below is a list of a few things you can consider in determining what’s best for your yard.

• Have a soil sample from your yard submitted for analysis to help determine if there is a pH issue or nutrient deficiency.

• If you know that you have higher pH levels, consider planting trees and shrubs that are more tolerant of alkaline soils.

• Try incorporating more organic matter into your soil by allowing leaves to decompose in landscape beds over the winter, and consider enlarging groundcover or mulch beds around trees (less lawn)

• Have root zone invigoration work done for trees that are struggling with nutrient deficiencies and/or soil compaction.

• Apply pH lowering products to landscape beds with particularly sensitive trees or shrubs (note that this is something that generally needs done annually, as permanently lowering the pH of soil with additives is next to impossible).  

As always, our ISA Certified Arborists are happy to help and you can contact us for any questions, issues, or inspections!

Additional Tree Preservation Articles!

Sincerely,

Walter Reins I Regional Manager, Russell Tree Experts

Walter became an ISA certified arborist in 2003 and has a degree in landscape horticulture. He has 25 years of experience in the tree and landscape industries and originally began working at Russell Tree Experts in 2011. Walter is also the owner/operator of Iwakura Japanese Gardens, a small design/build/maintenance firm specializing in Japanese-style gardens, and also offers responsible tree planting for all landscapes.

Tree Bracing 101

Dear Reader,

Trees adorn our landscapes, offering shade, beauty, and a connection to nature. However, ensuring their structural integrity and stability is vital for their longevity. Common tree preservation services that you may be familiar with are tree pruning and mulching. Other uncommon services could be cabling or trunk injections depending on the specific tree. However, throughout my 4+ years of working at Russell Tree Experts, one service that I have not heard of up until this year is tree bracing! Let's delve into the world of tree bracing to understand the process and benefits!

What is Tree Bracing?

Tree bracing? I couldn’t initially picture what this meant when first hearing it. Let’s first break down tree bracing into two words. Tree. Bracing. Tree: A woody, perennial plant typically having a single stem. I know what that is. Brace: To make (something) stronger or firmer, or to prepare for something difficult or unpleasant. So would it be a solid guess that tree bracing is the process of making a tree stronger? Yes! That’s exactly what it is!

Tree bracing is a tree preservation service to reduce the risk of two or more stems from splitting apart or to fasten a split or cracked union together, thus improving the overall structure of your tree. This is achieved through the installation of brace rods to prevent select tree unions from spreading or twisting apart or to prevent a split or cracked union from worsening.

This sounds great! Let’s start bracing every single tree to improve their overall structure! Well, not so fast. Only certain trees will stand to benefit from tree bracing. Just like fertilizing trees with manganese or iron to treat a manganese or iron deficiency, this service is only recommended for trees that need it, otherwise there would be either no noticeable effect or even a decrease in structural rigidity. Just like with pruning, which involves removing (or “wounding”) the tree’s crown of undesired parts, bracing is a semi-invasive procedure that involves installing large threaded steel rods into the trunk of the tree, so we only want to install brace rods when the net result is positive and beneficial. 

What Trees Should Be Braced?

So what trees should receive tree bracing? Well, as mentioned earlier, trees with a split or cracked union could benefit from brace rod installation. A split or cracked union should be easy to spot, especially in the winter in the case for deciduous trees as there is little to no foliage. A limb can split or crack due to various reasons like included bark (bark that is partially or fully embedded into the tree’s wood), improper pruning, disease, and storm damage from adverse weather like lightning, heavy winds, rainstorms, and thick layers of ice just to name a few. A split or cracked union can also occur from structural defects like large, long, horizontally growing limbs and codominant stems. If the limb is large and long and growing more horizontal rather than vertical, there could be a lot of weight-related stress near the union that could cause it to split if the limb is not supported properly or if end-weight reduction pruning does not occur. Codominant stems are two similarly sized stems originating from the same point of the tree and growing in the same, general direction. They can be characterized as having a tight “V” shape near the union or by both of the limbs competing to be the central leader of the whole structure. This is not ideal for a tree’s structure as they are prone to splitting during adverse weather conditions. In scenarios where removal of the branch or tree is not viable or preferred, tree bracing serves as a beneficial solution or alternative.

What Are the Benefits to Tree Bracing?

Tree bracing can be beneficial for a tree as they can minimize movement, ensuring the splits or cracks do not occur or worsen, especially during strong weather. A tree with poor structure or a split or cracked union may not want to be removed by the owner as it is a specimen tree (a tree chosen as a point of focus in a landscape) that provides aesthetics, shade, real estate value, or more. For some trees, it may also be unnecessary to remove them simply because of one or two weak, treatable unions that could even be healed over time. Tree bracing aims to improve the tree’s structure at a choice union and to give its owner more peace of mind that a union or limb has a decreased chance of failing, which would potentially end the tree’s life, or to keep it from falling onto something like a house, car, driveway, or anything else near the tree.

The Tree Bracing Process

Here at Russell Tree Experts, we use the ANSI A300 Tree Support System Best Management Practices to help guide us! With that said, before tree bracing begins, we typically prune the tree's crown to reduce weight and then install one or more cables in the crown to support the suspect union(s) from above. Once these initial steps are complete, we install a specified size and quantity of brace rods in your tree in accordance with the ANSI A300 Tree Support System Best Management Practices. The size and quantity is determined by factors such as the tree’s diameter below the union, number of limbs or unions being cared for, and whether or not there is or is not a split or crack present. To install the brace rods, holes are drilled straight through the tree near the union. The threaded brace rods are then fully inserted and will have excess rod on both ends. The brace rods are then secured with one or more washers, a lock washer, and a nut on both ends. The connections are then tightened as firmly as possible. Afterwards, the excess length of threaded rod is cut off close to the nuts and subsequently peened off to prevent any movement of the nuts. And voila! The end result is a tree with increased structural integrity and a reduced chance of failing! 

I talked with my coworker Jacob, our Training & Development Manager and an ISA certified arborist, read through the ANSI A300 Tree Support System Best Management Practices, and looked at other resources online to see if it was an acceptable practice to drill holes through a tree to install brace rods. After considering a variety of sources, the general consensus is that the overall impact is minor because almost all of the drilled wounds are filled with threaded steel rod (except a 1/32'' gap), allowing the tree to compartmentalize the wounds rapidly, and that tree bracing should be done on trees that have a bigger concern to worry about, such as two codominant stems or a split union.

Professional assessment is imperative to determine the necessity of bracing for a tree. Signs such as co-dominant stems or split or cracked unions should prompt owners to get an opinion from an ISA certified arborist. After researching, observing, recording, and photographing various trees being braced, I felt empowered and motivated to share my newfound knowledge on this not-so-commonly heard of tree preservation service! The main purpose of this Arbor Ed article is to educate and share my findings, but Russell Tree Experts does provide tree bracing services should you want or need it! Our regional managers are all ISA certified arborists and can provide a free inspection and quote! Below are some videos about tree bracing! 

Sincerely,

Enrique Arayata I Media Production Coordinator, Russell Tree Experts

In his free time, Enrique enjoys working out, hanging out with his girlfriend, video production and photography, cars, technology, cooking, and watching new movies and YouTube videos. He has a BA in moving image production with a double minor in film studies and studio art specializing in photography from The Ohio State University, an AA in web graphic design from DeVry University, and is an FAA Certified Remote Pilot.

Learn More About Tree Bracing!

Tree Work in the Winter?

Dear Reader,

“Can we get this work scheduled before winter kicks in?” “Do you complete tree work during the winter?” These are questions that I am often asked as the hibernal or winter soltice has arrived. In many cases, winter is the only time we can complete certain projects. This is due to the fact that many diseases and insects are not active, wildlife regulations are not in effect, visibility is increased, and the impact on landscapes is lessened due to winter’s colder conditions. Winter can be the perfect time for tree work.

One example of projects that must be completed during the winter is anything that falls under federal bat tree regulations. This typically includes public property projects where large trees need to be removed or the removal of any tree that could be a nesting site for bats. These regulations are intended to protect the Indiana Bat and the Northern Long-eared Bat, which are both currently endangered species. The importance of bats in our ecosystem is a story in itself. Bats typically overwinter in caves but move out to their nesting sites as early as April, therefore removal of possible nesting sites is regulated from March 31 through October 1. This is the main reason that the majority of our clearing operations and trail creation projects are completed during the winter months.

Winter is also also an opportune time for tree pruning to minimize the risk of insect and disease issues. For oak trees and elm trees, oak wilt and Dutch elm disease respectively are two devastating diseases that are be transmitted by insects (and root grafts) attracted to fresh pruning cuts. (Learn more here!) These insects are typically not active during the winter months, thus making approximately October 15th to March 31st the preferred time to prune oak and elm trees. If pruning cuts are required outside of this time window due to reasons such as storm damage, we highly recommend painting the cuts to minimize the risk of attracting the insects that can spread these diseases. Other trees that can benefit from winter pruning is the Rosaceae family which includes apples, pears, plums, and other fruit-bearing trees. The pathogens that infect many of these trees with diseases such as fire blight and black knot are typically not active during the winter months. Black knot is also much easier to see and prune out when the leaves are not present on our plum trees. Sanitation between cuts and proper disposal of these branches is imperative to slow down the spread of this disease.

Another reason for performing tree work during the winter months is the minimization of turf impact. Winter typically provides an absence of perennial and annual plants that are often planted under trees. Clients also tend to store their yard art, furniture, and other items that could be damaged during pruning and removal operations. This allows for our crews to be more efficient as less time is spent preparing the drop zone and moving items to a safe location prior to beginning any tree work. Thirdly, the winter months tend to be colder which provides a harder, sturdier ground that is more resilient to damage from limbs or equipment. As always, we do place mats on the ground if turf impact is a concern regardless of the time of year. Therefore, winter pruning becomes much more productive since there are fewer items that could be damaged otherwise.

Certain job sites such as golf courses, public parks, and street tree pruning, just to name a few, are performed during the winter months as there tends to be less pedestrians, allowing for better focus, less interference, minimized risk, and overall a more efficient and safe work zone.

As you can see, there are many reasons for scheduling a visit from your ISA certified regional manager this winter. With the absence of leaves on the trees, it is much easier for the trained eye to identify structural issues. Some structural issues may require a cable or even brace rods to secure your favorite tree in your landscape. Winter is also a great time to observe decay, fungi, or other pathogens that may not be visible during the summer when leaves are abundant and present. It is also the best time to observe cavities throughout the tree that may not be noticed while leaves are present. Dead, diseased, and broken branches are also much more visible when the leaves are not present in the winter months. Our arborists are trained to be able to identify the difference between dead and live branches even during the winter months. This time also allows the arborist to make quick decisions on improving the structure of the tree while pruning in the most efficient time of the year. Every day is a good day for tree care! Check out the video below to learn more!

Sincerely,

Mike McKee | Regional Manager, Russell Tree Experts

Mike graduated from Hocking College in 1983 with a degree in Natural Resources specializing in urban tree care. He has been a certified arborist since 1991. Mike started his career in the private industry in 1985 before becoming a municipal arborist in 1989. He retired after serving thirty years before joining us at Russell Tree Experts in Sept. of 2018. His love of trees has never waned since trying to climb up the ridges of the massive Cottonwood tree in front of his childhood home.

The Year of the Ugly Boxwood

Dear Reader, 

My good friend and arborist colleague Cat Baumgartner wrote the below article for the Inniswood Garden Society’s quarterly member newsletter (known as The Image). As soon as I read it, I knew that I wanted to share it with all our readers. Cat does a thorough job of describing the most serious problems we have had with boxwood this year and she explains them well and in simple terms. She has generously agreed to let us republish it. Photos within the body of Cat’s article are courtesy of Joe Boggs, OSU extension educator for Hamilton County.

- TJ Nagel, Russell Tree Experts

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The Year of The
Ugly Boxwood

by cat Baumgartner, Oakland Nursery

I don’t have a simple answer. Or there are multiple answers, and your boxwood might have one, or several of the problems at once.

I’ll go over the likely suspects for this year- including winter damage, or ‘winter burn’, Boxwood Leafminer, Volutella Blight, and THE Boxwood Blight.

I’ll start with winter burn. Boxwood store a lot of their energy in their leaves through the winter. When we get extreme cold and wind in the winter, the leaves will lose more moisture. If the ground is frozen or dry (or worse, both), the leaves lose moisture faster than the roots can replace it, and we get the ‘burn’, where they turn a straw color and die, staying attached to the stem. It wasn’t noticeable until early spring, because evergreens have a delayed reaction to stress. It’s why we can cut down trees for Christmas and they don’t immediately turn brown, often lasting months. We did have greater than normal rainfall last year, but the three months leading up to late December were on the dry side. So, the ground was dry leading up to the extreme cold event that hit in late December creating a Double Whammy. There was a lot more winter burn this spring than I’ve seen in decades. It looks like straw-colored sections in the shrubs, often in a random pattern.

Photo courtesy of Joe Boggs, OSU extension educator for Hamilton County. 

Next, there are different blights out there that can affect boxwood. ‘Blight’ is a general term for a plant disease, typically caused by a type of fungus. Most of them are less common and less damaging than the blight striking fear in the hearts of gardeners that is Calonectria pseudonaviculata, called simply “Boxwood Blight”. There have been some isolated cases in the Greater Columbus area. The main symptom though is defoliation. You’ll have green leaves, then they’ll start looking funny, and rapidly progress and fall off the stem. In a matter of weeks, you can go from a healthy-looking plant to one with sections with completely naked stems. Definitive identification requires lab testing. Other blights can show similar symptoms, but since some are more treatable, confirming which type of blight your boxwood might have is recommended before removing plants. If you do have “Boxwood Blight,” replanting with more boxwood is not recommended, so confirmation of what kind of blight you have will also tell you what you can plant in that spot. Most of the damage we’ve been seeing is NOT “Boxwood Blight.”

Photo courtesy of Joe Boggs, OSU extension educator for Hamilton County. 

Volutella Blight or Pseudonectria Canker (Pseudonectria buxi) can be damaging but is not necessarily a death sentence often just affecting individual stems and not whole portions of the plant. Symptoms can be seen if the stem is sliced into, showing dark brown streaking just under the bark. Most twigs infected with Volutella blight will turn straw colored and die. In most cases dead stems from Volutella canker can be easily pruned out and the remaining portions of the boxwood will fill in slowly over time. 

This year we also had frost damage in May. If leaf buds are still tight, frost is not a problem. If the new leaves have emerged, but have ‘hardened off’, it is also not a problem. But if the new growth is timed so that it is new, fresh and tender, and then we have a late freeze, the new growth is damaged, turns that sad straw color, and is aesthetically at least, a problem. A healthy shrub can put out another round of growth, and it is not a long-term problem. Trimming off the burnt new growth is all that needs doing.

Photo courtesy of Joe Boggs, OSU extension educator for Hamilton County. 

Boxwood Leafminer, an insect pest, is an ongoing problem. The damage from leaf miner is more generalized, an ‘all-over’ bad look rather than the chunky sections dying back. The adults lay eggs in the new growth in mid-spring, and as the larval stage hatches and begins to feed on the interior tissues, the leaves start looking bad, often having a blistered or bubbled effect, usually easier to see from the bottom of the leaf.   

Preventative sprays can thwart adult leafminers from laying eggs in the new growth, but need to be applied as you see the new growth. Systemics applied in the Fall or Spring can also provide control but know that boxwoods are insect pollinated. 

If you don’t have Boxwood blight, you have two options. Cut out the dead branches and let the plants regrow which may take three years or more to totally restore, in good condition, or replace the plants.

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A Final Note…

Since Cat wrote her article, we have had several boxwood shrubs test positive for yet another disease, Colletotrichum theobromicola (also referred to as boxwood dieback). This is a new disease for central Ohio and symptoms look similar to other blight diseases with the random dieback of twigs and straw-colored foliage. However, in addition to twig dieback, the pathogen also causes leaf spots that appear white in the center surrounded by dark brown margins as well as a bright black discoloration just beneath the bark along the twigs. The jury is still out on the best way to attempt to manage this disease but for now, good cultural practices such as removing symptomatic plants and sterilizing pruning tools between pruning different plants are the best-known strategies. Fungicides might also be helpful, but efficacy has not been determined. Laboratory testing should be used to confirm boxwood dieback because it can easily be misdiagnosed as other blight diseases. 

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Twig Dieback (Colletotrichum theobromicola)

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Leaf Spotting (Colletotrichum theobromicola)

As we continue to have more problems in the landscape with boxwood, it may be time to consider alternative plants that can achieve a similar function. Stay tuned for my boxwood replacement article later this Fall.

Sincerely,

TJ Nagel I Scheduling Production Manager, Russell Tree Experts

TJ loves trees. He is an avid gardener and plant collector. TJ graduated from The Ohio State University with a B.S. in Agriculture with a major in Landscape Horticulture and minor in Entomology. TJ is an ISA Board Certified Master Arborist and well versed in Plant Pathology. TJ joined Russell Tree Experts in 2012.

Anatomical Upgrades for Your Trees!

When you think of anatomy, what comes to mind? I think of humans specifically, and learning about the wonderful bone and organ systems in our body in middle school science class. You may think about the anatomy of various animals and how there is an abundance of variety depending on where you are in the world, but how often do we consider the anatomy of trees?

Surely trees are just trees, right? They grow without us even considering how or why they may grow in the ways that they do. We may be blissfully unaware of their anatomy or structure until we are confronted by the reality of a winter ice storm or a summer thunderstorm. Oftentimes, we may find trees with less-than-desirable structure having taken damage after these events, or worse, having caused property damage along with their own demise!

Two examples of trees with codominant stems

You may be asking yourself, what does poor tree anatomy look like? The answer to that question deserves its own article, however a majority of tree structural problems can be narrowed down to codominance, and that is what I want to address in this article. Codominance is when a tree has two or more similarly-sized trunks emerging from the same location and forming a distinct “V” shaped union. There are varying reasons as to why a tree may be codominant, and some species have natural habits that lend themselves to becoming codominant. 

Visual representation of codominance by Jacob Nau

To give you a visual representation of codominance, bring your elbows together in front of your chest, with your palms facing you. Now, spread your wrists apart, keeping your elbows together to form a distinctive V shape. Opening up your fingers you can picture the crown of a tree. Seems like an awkward, weak position to be in, right? Now, imagine adding the weight of tree branches, leaves, rain and 15-50 mph wind gusts, etc. (trees can go through a lot!), while you strain to keep your elbows together, and you can begin to imagine why a codominant union (V-shaped union) in a tree is not anatomically advantageous.

So what can be done to fix, or even prevent, codominant structure in a tree? The answer to this question largely depends on the age of the tree. If your tree is young and generally under the age of approximately 20 years, then a structural pruning plan can be performed to help guide the tree out of its codominance over the next 5-10 years. 

However, if your tree is large and mature, there are a number of services that can be used to help support your tree's anatomy. Those services include:

End-Weight Reductions

• Reduce the length of long, lateral branches in the tree’s crown to reduce the weight and levering effect on the codominant union below. Typically performed before or with a cabling support system.

Jacob Nau performing an end-weight reduction on a tree.

Cabling Support System

• Install a single, or multiple, static steel cable(s), or dynamic rope cable(s) in the tree’s crown to support the codominant union below.

A static cabling system in a Hackberry tree in Clintonville, Ohio.

Through-Brace Support System

• Install a system of steel threaded rods into the codominant union to strengthen that area of the trunk. This is usually performed in-tandem with a cabling support system.

Top Left: Final result of a brace rod installation. Top Right: Close-up of a singular, installed brace rod. Bottom Left: Side profile of two installed brace rods. Bottom Right: A brace rod about to be inserted.

Propping Support System

• Install a single, or multiple, semi-permanent wood prop(s) to support a lower, large lateral limb to ease the strain on a codominant union. This is a more unique way to support the tree's anatomy, specifically for low, long, and lateral limbs that are difficult to support with a cabling system.

A tree prop supporting a limb from the Angel Oak tree in South Carolina.

All of the services listed above, including the young-tree structural pruning, are services we perform at Russell Tree Experts. I highly encourage you to look out your window and consider your tree's anatomy! Can they be supported? Is it time for an anatomical upgrade? If so, give our local office a call at (614) 895-7000 and we will happily connect you with one of our Regional Managers to assist you in determining the best course of action for your trees!

Sincerely,

Jacob Nau I Training and Development Manager, Russell Tree Experts

Jacob is an ISA certified arborist and joined RTE in 2018. He has been involved in tree care for over 10 years. He enjoys climbing trees both recreationally and professionally and in his free time, he loves spending time with his family.

Why is Tree Pruning Important?

Dear Reader,

Tree care comes in many forms: insect and disease management, pruning, fertilization, cabling, lightning protection, and removals. Today I would like to talk about the importance of tree pruning and the various reasons why a tree may need to be pruned.

ISA Certified Arborist Andy Bartram making a tree pruning cut!

Tree pruning is the selective removal of branches from a tree with the general goal of improving the overall quality of the tree, whether it be for safety, health, structure, fruit and flower production, aesthetic appearance, and more. Some may view pruning as unnecessary as there are hundreds and thousands of beautiful, healthy, and unpruned trees out in the world that have grown successfully without human intervention. Although this is true, there are also many trees out in nature that are dead, dying, or unpleasant to look at. A native volunteer tree out in nature grew naturally from one of hundreds of seeds and competed with all the surrounding trees for resources. They are tough and independent and do not need any human assistance. However, the same cannot be said for a single tree or sapling planted by a human in a site where that tree might not have ever grown there naturally. These human planted trees often need extra care like watering, mulching, and fertilization in order for them to be strong and healthy.

Planting a tree sapling for our TREE FOR A TREE® program.

“Pruning” differs from “trimming” as pruning prioritizes a tree’s health and structure. Only the necessary limbs are removed and aesthetic appearance is a byproduct. With “trimming”, plants, shrubs, hedges, and trees are trimmed with the goal of improving their appearance. Depending on the individual trimmer, health and structure may be sacrificed in order to attain a certain look.

Andrew Schneider making a tree pruning cut!

A tree may need to be immediately pruned if it poses a safety concern. If there is a large or dead limb overhanging something significant such as a house, car, sidewalk, or valuable lawn decoration, that limb may need to be removed as it could be hazardous during a storm.

ISA Certified Arborist Mac McGuire pruning a dead limb overhanging a busy road.

If there are any limbs with clearance issues, it may also need to be removed. This applies to limbs that are touching any house siding or utility lines or any low hanging limbs that impede lawn activities or pulling into a driveway.

Another important aspect of tree pruning is for health and structural reasons. A tree’s overall health and structure will increase by removing any dead, dying, damaged, disease-infected, codominant, or crossing limbs. Removal of these limbs promotes new growth and increased flower and fruit production. When a tree is pruned, nearby trees, shrubs, plants, and grass can also benefit by receiving more resources like sun, water, and air. These additional resources can improve aesthetic appearance and promote new growth. If the pruned tree was also close to a window you may even have a better view from inside your house or more sunlight coming in during the day!

Unruly lilac in need of pruning.

As mentioned earlier, tree pruning can improve aesthetic appearance. Pruning does not focus on looks but removing dead, dying, broken, weak in structure, or clearance-issue limbs generally makes trees look neater, cleaner, and overall better. The pruned tree may not have a specific shape desired by an individual, but it will be healthier and safer. Another small factor to potentially consider is property value. An unmaintained tree can look unpleasant, unruly, and unsafe which can hurt the value of a property. When it comes time to sell, having a beautiful, healthy, and pruned tree can potentially increase property value, making it an easy worthwhile investment!

So now that you have read about the various reasons for tree pruning, you may be wondering when a tree should be pruned, how often should a tree be pruned, or how much of a tree should be pruned? The short answer is that it depends. Some trees are best pruned during a specific season and some may have no preference. For example, oak trees are not recommended for pruning from roughly April to October due to the risk of oak wilt. A sugar maple can generally be pruned any time of the year, but it is recommended that you prune a sugar maple during the summer rather than winter to avoid sap leakage from pruning wounds, which does not pose any significant problem to the tree’s health. 

Multiple water sprouts shooting straight up from a larger branch due to stress.

In terms of frequency, younger trees may need to be pruned every two to three years while more mature trees may need to be pruned every three to five years. The specific timing can fluctuate and vary based on planting site, climate conditions, potential insect and disease issues, and more. In terms of how much to prune, there should be no specific goal. Only remove the necessary branches. However, a general guideline is that no more than 25% of a canopy should be removed at one time as the tree may “go into shock” and grow watersprouts in an attempt to replace the stored energy lost from the removed branches.

If you decide to have your tree pruned, two incorrect methods of pruning that Russell Tree Experts and I strongly advise against are tree topping and lion’s tailing. Tree topping is pruning to create a rounded canopy that often requires cutting through a stem at an improper location. Lion’s tailing is the removal of many, if not all, secondary or tertiary branches from the interior of the crown, leaving most of the foliage at the edge or top of a canopy. Although the look of both of these tree pruning methods may be desired by a specific individual, they do not improve the overall health or quality of a tree and can actually shorten its lifespan and promote decay.

Examples of improper tree pruning: Tree topping (left) and lion’s tailing (right)

Tree pruning is a very large and vast subject with much to cover. Someone could write a novel about tree pruning and still not cover every single detail. The goal of this article was to discuss the many reasons for tree pruning, not necessarily to teach someone how to become a tree pruning expert. However, we do have an article and a video on the 3 cut method that will be linked down below for anyone interested in learning how to safely and effectively remove a limb! A few additional tree pruning-related articles will be linked down below as well.

Interested in Pruning Your Own Tree?

Check out these other Arbor Ed articles!

The Value of Trees in the Urban Landscape By Chris Gill: https://www.russelltreeexperts.com/arbor-ed/2018/9/18/the-value-of-trees-in-the-urban-landscape?rq=tree%20pruning

Preventing Tree & Property Storm Damage By Chris Gill: https://www.russelltreeexperts.com/arbor-ed/2018/8/14/storm-damage?rq=tree%20pruning

Where’s the Fruit? By Krista Harris: https://www.russelltreeexperts.com/arbor-ed/2021/2/1/wheres-the-fruit?rq=tree%20pruning

Stop! Don’t Top! By Chris Gill: https://www.russelltreeexperts.com/arbor-ed/2018/10/9/stop-dont-top?rq=tree%20pruning

Sincerely,

Enrique Arayata I Media Production Coordinator, Russell Tree Experts

Enrique is a fourth year student at The Ohio State University majoring in moving image production with a double minor in film studies and photography. In his free time, he enjoys fitness, video games, technology, cars, videography, photography, and cooking.

Ask an Arborist: When is the best time of year to get trees trimmed?

The dormant season is a great time of year to prune your trees, Sandra. This is basically from October through May. In the dormant season, the leaves are off so it is easier to see structural defects within the canopy of your tree. It is also a time of year when there are fewer insect and disease issues that sometimes or attracted to fresh pruning wounds. Sometimes customers have concerns about our cruise being able to identify dead limbs when there are no leaves. This is done by looking closely at the bark and if needed, the color of the cambium layer with a small scratch on the bark of each branch. Long story short: Now is a great time to trim your trees!

-Joe Russell, Russell Tree Experts