What's Wrong with my Sycamore & Maple?

"Why does my beautiful maple have ugly black spots on its leaves?"

"Why is my American sycamore bare this year?"

By Krista Harris
ISA Certified Arborist® OH-6699A
May 22, 2025​

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Anthracnose fungus attacks newly emerging leaves in the spring when the weather is just right for disease development. The symptoms vary from host to host, but typically infected leaves will have irregular dark spots along veins. Eventually, the leaf will curl, die, and fall. In the case of the sycamore, often the leaf buds are killed before they have even had a chance to emerge.

[Sugar Maple leaf before and after anthracnose fungus]

Anthracnose fungus affects many deciduous trees and seems to be most noticeable this year on sycamore and maple in our area. I have had at least 10 customers per week concerned that their beloved trees were dying due to this fungus. I have also been driving by my favorite American sycamores around my home, only to find them very sparsely leafed and struggling. This includes Upper Arlington's oldest tree, an amazing 3 stemmed beauty that our team pruned a few months ago.

[American Sycamore leaves with anthracnose fungus]

Thankfully, I have wonderful news for the stewards of these afflicted trees. Anthracnose is a cosmetic disease for the majority of trees! If the tree is otherwise healthy and well established, it will be just fine. It will replace those lost leaves in July when conditions no longer favor anthracnose development.

How can you help trees with this seasonal infection?

1. Water your trees during our hot, dry summers! Concentrate the water at the ground level only, do not splash the leaves. All trees will appreciate the extra water, but those that have lost their leaves and are attempting to replace them will relish it! ARTICLE: HOW TO WATER YOUR TREES

2. Prune your trees for better air circulation and light penetration. This will help the leaves dry faster and it will be harder for the fungus to spread.

3. Dispose of affected leaves so that the spores are not hanging around next year to re-infect your tree.

4. Consider fertilizing your trees in the spring so that they have the needed nutrients to stay healthy (and possibly put on 2 sets of leaves if it is another good year for anthracnose infection).

Above all, do not panic! We cannot control the weather or the fungus. Just concentrate on overall tree health and by mid-summer, the trees will have recovered and this disease will be just a bad memory. For a free tree quote by one of our 20+ ISA Certified Arborists®, visit RussellTreeExperts.com/Quote or speaker to our friendly, local office staff at (614) 895-7000!

Please note: This article was originally published on 6/14/2021 and was revised on 5/22/2025.

ADDITIONAL ARBOR ED™ ARTICLES!

Krista Harris | Journeyperson, Russell Tree Experts

Krista grew up in the central Ohio area and became an ISA Certified Arborist® in 2017. She graduated from The Ohio State University with a Bachelor of Science in Crop Science and a minor in Plant Pathology in 2000 and has been in the green industry ever since. Her favorite trees are the American sycamore, American beech, and giant sequoia. [BS in Horticulture Crop Science, The Ohio State University / ISA Certified Arborist® OH-6699A / ODA Comm. Pesticide Lic. #148078]

The Small Hours

Dear Reader,

Welcome to the no man’s land that is the front line between a winter that does not want to surrender and a spring that is determined to break through. Two weekends ago on the 13th I did some late winter camping in reasonably mild weather with a forecast that promised no precipitation on the 14th. I spent the day in the woods with my father, clearing some paths and just enjoying being outside. I noticed buds on a spicebush (pictured below) that were getting a little excited and were starting to swell. Things are waking up! I love seeing the first signs of spring that remind me life is flowing beneath the surface.

Sometime around midday we sat down on a log to eat some bread and cheese. That’s when I heard what sounded like someone was sprinkling sand onto us from up on high. I looked more closely: yes, sleet was falling and collecting on my clothes. As the afternoon progressed the sleet intensified, then got wetter, eventually turning into snow that did not stop through the two hour drive home. By the time we made it home there was a good inch of snow everywhere. Amazing how quickly things can change.

The snow was gone by Monday, and I spotted my first forsythia in bloom (below) at a client’s house. Another sign that winter is fading away! Supposedly there will be three more snows left after the forsythia blooms. I wish I knew if this forsythia had bloomed before or after the snow two days ago!

My week progressed with more of the same. The earliest of spring flowers were coming out. They are usually not very conspicuous, only revealing themselves to those who are looking for them. These early bloomers are more demure, not willing to make a big splash this early in the party. Things are still quiet, but the arrival of these first guests means things are going to get louder very soon. 

Here is a red maple in full bloom a day later:

And one day later, on Wednesday, Cornelian-cherry dogwood, making its subtle statement…

And on Thursday I had to stop and admire this pussy willow collecting raindrops on its swelling flower buds:

All during this time I have noticed wildlife waking up as well. I saw a garter snake in my back field pretending I couldn’t see it. I walked around it not wanting to hurt its feelings. In the same area, some ants were slugglishly thinking about doing some spring cleaning; I could tell they still needed to finish stretching out a bit before they started to work. Birds are way ahead of them – I saw a wren picking through some straw for some nest building materials while her mate kept watch a few yards away. A pair of sparrows is nesting in one of my porch columns. Birds are singing away the silence of winter, and even the spring peepers did not stop their call through a low in the mid 20’s that weekend. I guess the plants and animals are just as tired of gray, cold weather as everyone else is. 

As I reviewed these photos to share them with you I noticed the background in each one is gray, overcast skies. Given recent developments around the world and now in our own community I could not help but draw a parallel between these photos and what is happening in our world. The sky above seems gray, temperatures go up and down. News updates keep coming in. Today it’s rain, tomorrow it’s snow. We have to stay inside, looking out the window wondering if spring will really come. But I have been outside, and I’ve seen the buds swelling, the flowers emerging, the birds and animals getting on. I’ve had the true pleasure to be able to speak with several of you last week as we met in your lawns to discuss trees, plants, and other things. Yes, we had to keep our distance, but it’s amazing how there is no distance between a friendly smile and a word of encouragement shared between two people. Yes, it is amazing how quickly things can change. Yes, the sky overhead may seem gray, and we are tired of staying inside waiting for the world to change back into a more comfortable place. But I have seen the signs of life carrying on in your landscapes and in your hearts. Yes, for now we keep our distance, but a wave, a smile, a letter, a telephone call will serve to remind one another that this miracle we call life is far greater than we understand, and if we keep moving forward together, the gray skies will clear and we will see that the sun was always there behind the clouds. 

“Sorrow may last for a night, but joy comes in the morning.” Winter would like to remain in the world and in our hearts, but life and light are so refreshingly and so reliably rebellious. May that spring morning come soon for all of us.

Your friendly neighborhood arborist,

José Fernández | Regional Manager, Russell Tree Experts

José became an ISA Certified Arborist® in 2004, and a Board-Certified Master Arborist® in 2015. Currently he is enrolled at The Ohio State University pursuing a Master’s Degree in Plant Health Management. José likes working around trees because he is still filled with wonder every time he walks in the woods. José has worked at Russell Tree Experts since 2012.

Test Before Treatment: Soil & Tissue Testing

Test Before Treatment

I find it interesting that test procedures recommended in the medical field for human health have become part of the expected methodology, but not so much in arboriculture, for tree health. As arborists, we are trained that a soil test should be done prior to recommending fertilization, for example, but I don’t know of many outfits that make soil sampling a part of their modus operandi. On the other side of the equation, many clients will choose not to do a soil or tissue sample when presented with the option, perhaps because of budgetary reasons. I think it is time this started to change, because knowledge of a problem is the first step toward the solution. Given an unhealthy tree, I might suspect what the problem is, but unless it is one that is readily identifiable in the field, I would rather start with the sampling than attempt a treatment.

Click here to see the 9-step soil testing process!

Fertilization is one instance where a soil sample, at minimum, should be taken. For fertilization, a tissue sample would also be good, for reasons I will get into shortly. Another instance when plant samples are usually taken is when a problem is not readily identifiable in the field, and the problem is not so developed that treatment is still a viable option. A third instance where sampling is necessary is to rule out the possibility of a disease which could spread to neighboring healthy trees. In this case even dead plants may be sampled to detect the presence of one of these pathogens if possible, and to know how to dispose of the dead plants properly.

Fertilization

In general, “tame” trees and shrubs in finished landscapes benefit from fertilization because they are growing in conditions that do not resemble where they would be growing if they were “wild”. I may not need to sample the soil in an urban landscape to know that usually the addition of organic matter is going to benefit the trees, along with the nitrogen that composted organic matter provides for growth. Also, I know that most of the soil we find in the Columbus area is a limestone based, heavy clay soil. This particular bit of knowledge has led to some confusion in particular tree treatments I am about to discuss. (If you have Pin Oak, River Birch, Maple, Sweetgum, or Sweetbay Magnolia on your property, read this section if nothing else!!)  Arborists have traditionally been taught that chlorosis (yellowing foliage) in these trees is due to either a deficiency of iron or manganese in our heavy clay soils. If the tree is a Pin, Red, Shingle, or Sawtooth Oak, you treat it with iron. If the tree is a Maple or a Sweetgum, treat it with manganese. At this point in my life I don’t recall what the recommendation was for the other trees. Why not?

Chlorosis in a Red Maple

Chlorosis in a River Birch

After years of treating trees this way with very mixed results, I had the good fortune of meeting Dr. Darrah at CLC LABS. His findings over the years for our Columbus soils, related to chlorosis in these trees, have been that the problem is nearly always a manganese deficiency. To make matters even worse, giving iron to a tree that has a manganese deficiency appears to make the manganese deficiency even more pronounced. To this day I continue to be filled with satisfaction when I drive past a tree that was not responding to year after year of iron treatments, in the soil and with trunk injections and implants, to no avail, by someone else. Then, after sending soil and tissue samples to the lab, we found a surplus of iron and a dearth of manganese. The remedy? Treat aggressively with manganese. Sometimes the result is immediate, most times we see a turnaround after 2-3 seasons of treating appropriately. But what a satisfying feeling to know that we have figured out what the problem was, and now the symptoms are being reversed! To be clear, the satisfaction does not come from knowing we were right and someone else was wrong!  It comes from seeing a tree that was in decline start to come back to life.

Click here to see Dr. Darrah at CLC LABS perform soil testing!

When I encounter chlorotic foliage in trees now, my top suspect for nutrient deficiency  is manganese. If a tree is only beginning to show symptoms, I may recommend manganese to see if it turns around. If it does not turn around, we can sample to see what the issue is. Why take this backward approach? Maybe because I have a subconscious fear that a client may feel that I am just trying to sell additional services that are not needed. Especially if the other two arborists (from other companies) she spoke to “never recommended sampling”. And in her mind she may be thinking “Why does this arborist need to take samples? Can’t he tell what the problem is? And anyway, the other arborists said the issue was iron, not manganese.”  So, since I know there is a very high chance the problem is manganese, that’s what I will recommend. 

BUT, there have been a very small number of samples that came back showing some other micronutrient deficiency (or surplus), that was critical for knowing what the best treatment approach was. And this is why sampling should always take place first. I pledge to offer that as the first step in a treatment plan to each client with a sickly tree. At least then I will have done my due diligence.

As a final note for fertilization, if the time of year is right, a tissue sample is great for getting a more complete picture of what is happening in the tree.  By comparing soil to tissue, we can see what is available to the tree and what is actually inside the tree.  This helps with diagnosing the cause for symptoms. 

Sampling for disease diagnosis, live or dying trees

There are many diseases arborists can positively identify in the field if properly trained, and they should be able and willing to show the client what they are seeing, and why it needs to be treated (or not). I still find insects that pop up sporadically that I have never seen before. Usually I can pull out the reference books back at the office and find the pest or pathogen, but if I fail at that, it is time to take a sample to the clinic. Even if an arborist had exhaustive knowledge for field identification of diseases (which is a tall order), there are certain diseases that require a specialized lab for a positive identification. In the case of live trees, one may decide that sampling is not needed due to how advanced the symptoms are. If the tree is not salvageable, perhaps sampling is not the best use of funds. But if the symptoms are those that could be of an infectious nature, threatening other live trees, sampling is paramount, and should be done promptly.  Let’s look at Oak Wilt, for example. 

Several years ago, Russell Tree Experts submitted the first positively identifiable sample of this disease taken from a tree in Franklin County. The year prior, a consulting arborist had turned in a positive sample from a tree in Delaware County. Oak Wilt is a disease that was known in the northeastern counties, and we were sad to see it moving into our neighborhood. However, had we not taken the samples, we would not have known the steps to take to properly dispose of the dead trees, inoculate the surrounding live trees at high risk of infection, and try to get the word out to the local arborist community. That was several years ago. Since then, more and more arborists have had positive samples, but to my chagrin, I still run into trees that I am fairly certain died of Oak Wilt but were removed willy nilly by “arborists” who maybe never even thought why the Red Oak went from live to dead in a matter of days. It takes time for word to get around, and it takes tree owners who are concerned about their trees.  

I am happy to say there are several reputable, trustworthy tree care companies in the Columbus area whom I am proud to count as colleagues (and I hope they feel the same way about us!).  This provides discerning clientele with plenty of good options to choose from. I am also very happy that more and more people are realizing how important the care of trees and plants is – not just for the love of their own back yard, but for the good of their neighbors.  How do I know you are out there? Because you take the time to read these thoughts that flow out of my fingers into the keyboard. As I write this, early evening is coming on. I am looking out my window across a field divided by a small stream. Green grass in the foreground flows to the border of the stream, outlined in buckthorn turning yellowish green, brilliant yellow Maple on the left, defoliated Cottonwoods against the sky. Anchoring the scene on the right is a large Pin Oak turning an orange bronze. When the sun shines it lights up like fire. Across the stream a recently harvested soybean field, the color of straw. In the background, all across the window frame, stretches a native woods made up of what appears to be mostly Oak and Hickory: rusty, ruddy, yellow, gold.  Above the green grass, tan straw, and tree line made of fire a sheet of sky in light gray is spread, with a hint of pink peeking through here and there. 

Stop for a moment.  Look around.  Let peace find you, and give thanks for it. The more we notice it, the less we can take it for granted.

Your friendly neighborhood arborist, 
José Fernández

José Fernández | Regional Manager, Russell Tree Experts

José became an ISA Certified Arborist® in 2004, and a Board-Certified Master Arborist® in 2015. Currently he is enrolled at The Ohio State University pursuing a Master’s Degree in Plant Health Management. José likes working around trees because he is still filled with wonder every time he walks in the woods.

Verticillium Wilt

It’s hard to miss this disease once we enter the hot dry months of summer.  Without fail, each July/August I start to see trees turning brown and wilting suddenly, usually in patches within the canopy that can be traced back to entire individual limbs that have died.  More dramatically, an entire tree will just turn brown and wilt. The pattern of wilting is very regular, and the symptoms can carry over into winter because the wilted leaves sometimes stay on the tree well after normal leaf drop in the fall.

Verticillium Wilt (VW) is easily recognizable once you know what to look for, but not easily treated.  To make matters worse, it affects a large number of trees and plants, with varying expression of symptoms from tree to tree.  During my years as an arborist, I have found Norway Maple, Japanese Maple, Yellowwood, Smoke tree, Redbud and Magnolia to be very common hosts of this disease.  And this is a short, short list of the plants that can be affected.  

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Dead Sugar Maple, suspect VW due to suddenness of wilting

The disease is caused by a fungus present within the soil, and there are so many ways it can get into the soil that my approach is usually “if there is soil present, there is probably VW present”.  What do we do? It sounds like a copout, but the best answer for dealing with this issue is the best answer for dealing with most plant pests and diseases: Choose the right plant for the site conditions. This is the best way to cultivate healthy plants that can naturally cope with the more problematic neighbors within an ecosystem. But this doesn’t really help the tree that has already been planted and is making do with what it has.

If the tree has already been planted, the next best option is to do everything possible to manipulate conditions at the planting site to minimize stress factors to the tree. Ensuring proper moisture, adding organic mulch matter, amending soil both chemically (fertilization if needed) and physically (soil aeration/relief of compaction) are all good measures that can be taken.  There are systemic fungicides that can be applied to suppress the development of the disease within the vascular system of the plant as well, but these applications should be secondary to the site work.

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Dead vascular tissue in Sweetbay Magnolia characteristic of VW

The fungus can enter the tree by wounds in roots but can enter roots even when no wounds are present. Once in the tree, the disease tends to progress upward and outward, causing foliar wilting and dieback to varying extent.  I have seen trees coexist with the disease for years and years, seemingly keeping up with the disease, losing a branch here and there, but generally coping with it. On the other hand, I have seen trees decline quickly. I recall one Sugar Maple which barely had any symptoms until it wilted from head to toe and died over the weekend.

In closing, I feel that VW is an example of how trees really die. There are questions that need to be asked, such as “Was it just a super-virulent strain that entered the tree?” or “Was it a weaker strain, but the tree was just weakened by multiple other factors?”. Sure, there may be cases where everything is perfect for the tree, but the disease was like The Terminator -  unstoppable. In my experience though, most trees die because something else has made them vulnerable and weak enough that a relatively low-grade disease is what finishes them off.  In that case, treating the disease is a last-ditch effort that can only really work if the treatment keeps the tree alive long enough to benefit from the effects of cultural changes that should be implemented if possible.

I think there is a life lesson that can be applied here, but I will let the reader sort that out. Have fun out there!  For every wilted leaf, there are 100 other green ones.

Your friendly neighborhood arborist, 
José Fernández
ISA BCMA® OH-5129B

The Importance of Green Leaves

Chlorosis in a River Birch causing a die-back in the canopy

I have been noticing what I consider to be an unacceptable amount of chlorosis in urban trees around Columbus. In general, chlorosis is the yellowing of plant foliage caused by a lack of chlorophyll. This is a problem because plants depend on chlorophyll to absorb energy from sunlight and to survive.

Several factors can contribute to the development of chlorosis in trees such as nutrient deficiency, drought, poorly drained and compacted soils, girdling roots, graft union incompatibility and mechanical damage to the tree trunk. For the purpose of this article, I’m going to focus on chlorosis caused by nutrient deficiency because I believe it’s the most prevalent and most often mismanaged. Although any nutrient deficiency could lead to chlorosis in trees, manganese and iron deficiency is what we see most.

Chlorosis in a Red Maple

Chlorosis in a Pin Oak

It is important to understand that the availability of nutrients from the soil can vary with soil pH.  For example, even though there may be an adequate amount of manganese for a certain tree in the soil, the soil pH can cause the manganese to be inaccessible by the tree. Most urban soils in central Ohio are alkaline. (A quick review for those of you who fell asleep in biology, the soil’s pH is an indicator of soil acidity or alkalinity. On a scale of 1-14, 7.0 is neutral, below 7.0 the pH is acidic, above 7.0 the pH is alkaline. Nutrients are most available to trees when the soil pH is between 5.0 and 6.5. Because most of our urban soils have a pH of around 7, we find ourselves dealing with chlorosis.

Initially, chlorosis expresses itself in the canopy of trees by the yellowing of foliage with a network of green veins.  As the chlorosis progresses, leaves become a paler yellow and develop brown necrotic lesions. Leaf margins will eventually brown completely and leaves will dry up and fall off.   Over time this results in poor vigor, reduced twig extension, poor density of canopy, dieback and eventual tree death.

The easiest way to manage chlorosis is to prevent it by planting urban tolerant trees that are tolerant of high pH soils. Although most trees species have the potential to develop chlorosis, the most common trees affected by high pH soils in central Ohio are Pin oak, Red maple, River birch, Shingle Oak, Red Oak, Sweetgum, White pine, and Canadian Hemlock. If you notice yellow leaves on your trees (and it is not time for Fall color) it is important to take action for long-term preservation. 

Russell Tree Experts Tree Wellness Technician Collecting a Soil Sample

The first step is to have a soil and plant tissue test performed. This is the only way to know which nutrients are lacking in your trees and soil. Any attempt at correcting chlorosis without the information from these tests is guesswork and treatment without proper diagnosis is malpractice. We can have these tests performed for you,  interpret the results, and determine the best management for your tree(s).

Just another way Russell Tree Experts is keeping Ohio green!

TJ Nagel
ISA CERTFIED ARBORIST® OH-6298A