Declining Trees: Why Does it Happen and How Do We Spot it?

Chelsi Abbott, technical advisor within the Davey Institute, shares what the signs of tree decline are, along with what homeowners can do to spot and prevent it. 

In this episode we cover: 

• Why do trees decline? (1:37) 
• Water supply is the root issue (2:44)
• What are the signs of tree decline? (4:02)
• What can we do to intervene? (6:00)
• The timeline of tree decline (8:02)
• What it's like to be a technical advisor at Davey (10:12)
• Fungal issues (12:37)
• What to do if you spot a fungal issue (14:23)
• Best advice for homeowners on how to avoid decline (15:52)

To find your local Davey office, check out our find a local office page to search by zip code.

To read our Insect and Disease Issues blogs to learn the best ways to spot and prevent tree decline, visit Blog.Davey.com by clicking here - Insect and Disease Issues.

Connect with Davey Tree on social media:
Twitter: @DaveyTree
Facebook: @DaveyTree
Instagram: @daveytree
YouTube: The Davey Tree Expert Company
LinkedIn: The Davey Tree Expert Company 

Connect with Doug Oster at www.dougoster.com. 

Have topics you'd like us to cover on the podcast? Email us at podcasts@davey.com. We want to hear from you!

Transcript

[music]

Doug Oster: Welcome to the Davey Tree Expert Company's podcast, Talking Trees. I'm your host, Doug Oster. Each week, our expert arborists share advice on seasonal tree care, how to make your trees thrive, arborists' favorite trees, and much, much more. Tune in every Thursday to learn more because here at the Talking Trees podcast, we know trees are the answer.

Before we get started today, we are looking for your tree questions. We would love to do a whole episode where arborists are answering your questions. That might mean just sending a question in via email, or maybe I could record you asking a question. Reach out to us via email at podcasts@davey.com. That's P-O-D-C-A-S-T-S@D-A-V-E-Y.com, or you can click the link at the end of the show notes to text us a fan mail.

Again, your ideas could be on a future show. This is going to be fun. On to the show. I'm welcoming back Chelsi Abbott. She is a technical advisor at the Davey Institute for the Davey Tree Expert Company. Chelsi, welcome back to the show. It is great to talk to you again.

Chelsi Abbott: Thank you. As always, I'm happy to be here.

Doug: It's the first time we've ever talked that wasn't specifically about fungi or fungus.

Chelsi: Oh, my goodness, I can talk about something else.

Doug: Oh, no. We'll get some fungal stuff in there, I'm sure.

Chelsi: Thank you. Because I really do like to talk about fungi.

Doug: Oh, I know it. Believe me. Today's topic, why trees decline. What is the first thing on your list when I ask you that question? Why is my tree declining? Certainly, there has to be somebody on site and looking at it, and there's all sorts of different reasons, but in general, what are you thinking?

Chelsi: It's a good point, and we'll get there. Really, the large point is that there's not one-size-fits-all. In typical, when we think of decline, think about it's a result of limiting resources. Now, multiple factors can limit those resources, but essentially, decline is just the tree is not getting what it needs to grow, so then it starts to decline.

Doug: That means fertilizer, that means soil, that means diseases, that means what else? What am I missing?

Chelsi: Run the gambit. Typically, let's say, again, we'll be pretty regional here because it's going to be different everywhere, but right now, I'm located in Illinois. Right now, we're seeing a lot of decline. The root issue is, honestly, lack of water or lack of ability for water to get from point A to point B. Insects or diseases, or other factors, essentially block that water from moving around, which means the tree cannot photosynthesize to the max. Then it starts to essentially not make itself enough food, and so it slowly starves.

Doug: Here, a little further east, we're getting way too much rain.

Chelsi: That's right. Too much water can be just as damaging, if not more damaging, than too little water. That's one of the things that I talk about when I talk about decline is find the limiting resource or find the reason for the limiting resource. If it's water, figure out, is it simply just there's not enough or too much, or is there something blocking the water, like a disease or an insect.

Or could something be stealing the resources from the tree? These are things like foliar insects and foliar diseases where they're stealing away that photosynthetic tissue. If they do that year after year after year, again, there's your reduction in your food source. That's another reason that trees can decline.

Doug: Let's talk from a homeowner's standpoint, what are some signs that they can, if they're looking at their tree, that it is in decline?

Chelsi: Yes, this is a great question. Typically, trees within decline, usually we don't see it until they're maybe a little bit at advanced stages just because it happens slow at first and it ramps up quickly. The very, very beginning symptoms that you might see would be, for example, early fall color is a big one, a big symptom of stress. Reduced growth, like the shoots aren't growing as long, the leaves aren't growing as big as they typically do.

These are the very first symptoms that a tree might be showing you, "Uh-oh, I, for whatever reason, am starting to maybe pull back on the amount of growth that I can actually do." Then as we get further in the stages, you'll see limb dieback, so that's where the leaves no longer are coming out on the branches all the way out to the tips. Then you'll see larger limb dieback. As we get more advanced, whole crown or whole parts of the crown will start to defoliate or not come out of winter. Then eventually, the tree itself will just not come back from winter, or it'll defoliate and crap out during the season. That's the progression of decline.

Doug: Well, it's pretty easy to see then, right?

Chelsi: Yes. It's easy to see when there's no leaves, but oftentimes by the time there's no leaves-- one of the big concerns about decline is by the time you see the major symptoms, we're pretty behind the ball. Especially since a lot of the, let's say, core issues around why trees decline, which is a lot of water relations, as well as in general climate-related problems, they're big issues that we might not be able to fix or at least fix in time for what stage that tree is in. I'm sure your next question is what will we do?

Doug: Well, after all that, now what do we do, Chelsi?

Chelsi: Yes. Let's imagine we're in the very early stages of decline. We've actually diagnosed maybe what's causing the limiting or the stealing of the resources. Obviously, the first fix is to stop whatever is stealing or limiting. Then beyond that, since most decline is a lack of resources, what we're probably going to try to do is replace those resources. Whether it's nutrient, we're going to try to put down water if it's a water issue. Relieve some drainage issues if it's too much water.

It's a lot of cultural care. That's, again, the tricky part with it is there's no quick fix. It's a long-term investment. Or if you can do it preventatively, that's best. When we talk preventative care, we're talking ensuring that you're mulching and mulching correctly. Ensuring that it's getting adequate water, not too wet, not too dry. Making sure that the soil is overall healthy. Not damaging the root system. Those types of things. Those are precursors to a lot of decline.

Doug: I did want to talk preventative. I'm thinking also of having somebody regularly on site. That has saved me time and time again. I've got an arborist from Davey coming every six months. For us as homeowners, we're just not as keyed into seeing things. Usually, it is when it's too late.

Chelsi: That's a great point because arborists, their whole jam is trees. They can typically see a symptom associated with decline a little bit sooner than a client can. A lot of times, they might be able to point out symptoms of stress so that we take care of it before it's to the point where we're like, "Oop, [chuckles] we're going to lose that limb, and then hopefully try to save the rest."

Doug: For years, we have this healthy tree, and then one year, halfway through the season, something happens. Why now? Why is it happening now?

Chelsi: Yes. That is the golden question when it comes to decline. Many times when I'm on site diagnosing decline, the client points out that this tree was looking great last year. Of course, remember there are some small symptoms that may have been missed. Then suddenly, it appears like we're losing large limbs, and we're not getting all of the tree. The best analogy I have is to think of trees as having a bank account.

Every year through photosynthesis, they put money into the bank. They're able to build up stock resources, and they save it in their woody tissue for a "not-so-rainy day." If they come across a day where they're not able to make their own food, they'll just pull it out of their bank account, and they'll just pool those resources.

Now imagine what happens in decline is the tree is just simply not making enough money, but it continues to withdraw money, the same amount every single year without putting enough money in because remember, it's a limiting resources sort of thing. Then what happens with decline is eventually that tree goes to reach into the bank account, and there's no money left. It hits that wall at that time because it simply ran out of storage, and it just doesn't have any money left in the bank account. You get your overdraft fee, and then that's when you start to see decline.

Doug: Normally, when a tree is getting to that end point, are we seeing anything, or it's just when it gets to that point where I can't take anything else out of the bank, that's when we start to see it?

Chelsi: That's the point. That's when we start to see the large limb-- again, there's been symptoms, a little red flag, let's say alerts from the bank account saying, "Hey, you're getting close to zero." They can be a little subtle, but then when we start to see that large limb dieback, or whole trees not coming out of winter, that's the wall I'm talking about.

Doug: Tell me a little bit about your job as technical advisor. Tell me a little bit about your day. Are you out looking at trees? Are you in a lab, or what are you doing?

Chelsi: Yes. Largely, my job as a technical advisor is a diagnostician, but a diagnostician in the field. I have my own little microscope set up, but I don't largely work in a laboratory setting, at least not a traditional one. Most of the diagnostics that I do are field diagnostics out on site, either with arborists or by myself, identifying abiotic issues like decline or biotic issues like diseases and insects, which are a part of decline.

Doug: Are they calling you out? Are they looking at a tree and saying, "I'm not sure, we better call Chelsi," or are you out there in some other capacity?

Chelsi: No, I'm out there typically as a support to arborists, either A, because they can't figure it out, or a lot of cases just to be a corroboration or maybe a second opinion for-- again, decline is a complex issue to diagnose because usually it's more than one thing. It's environmental. There's diseases and insects that can get into play. Sometimes it's nice to have someone else come out and say, "Yes, I see what you're seeing, and that does make sense the way that you've described it."

Doug: That's interesting because that's the same way it happened for me with oak wilt. Arborists saw the leaves. I called them on. I said, "Hey, this tree is dropping leaves." He looked at it and he goes, "I think so, but bring somebody else out to verify it." They verified it, so I'm stuck with it.

Chelsi: Oops. [laughs] Sometimes I tell people, I was like, "Hopefully we never meet again," because usually if I'm called out to a property, it's pretty bad. [laughs]

Doug: Well, that's an interesting point you make because I talk about this a lot with arborists about the opposite, about being able to come out and say, "Oh, no, don't worry, that's lichens or this is-- Yes, it does that." Yours is the reverse.

Chelsi: Yes, I've been playfully, I think, called the grim reaper a couple of times because I come out with bad news a lot of times. [laughs]

Doug: Where I'm at, we are getting just so much rain. To me, that adds up to fungal issues. This is something you and I have discussed over and over again. I know that's one of your expertise. Let's talk a little bit about it, about when you have a real wet early part of the season. In my case, you've got flowering crabs, so there's going to be an issue there. Other trees, too.

Chelsi: You're hitting on one of the core tenets of how it's so difficult to really talk about decline is because you're talking about too wet. You've already got a tree that's struggling because it's got too much water. Now, that's really making the host more susceptible to problems. Then that conducive environment also drives fungal pathogens. What we're seeing there is that's that double whammy.

We can oftentimes say things that weaken a plant host and maybe start the decline process, typically those environmental conditions push pathogens and pests to increase in their populations, which then get attracted to the stressed-out host and cause more damage. That's the decline spiral in a very short little package.

Simply put, yes, the increase in water, or in some cases drought stress, can cause fungal issues to essentially be better pathogens. These stressed-out hosts start getting double whammy hit with fungal pathogens, insects, lots of other things, either taking advantage of the environment or the stressed-out host.

Doug: If I see a fruiting fungal body at the bottom of my tree, what should I do?

Chelsi: Well, first off, not all fungi are bad. There are actually plenty of good fungi. Now, if it's attached directly to the bark, you can see it's actually growing off of the tree. There's two options here. It could be, A, something that's pathogenically attacking the tree. Then there's the second option in which it's a fungi that is maybe more taking advantage of a wound.

Either way, it usually means there's decay there. Again, I'm talking about a fungi directly attached to the tree. There's decay there, but whether it's causing it or taking advantage of it, we really need to ID the fungus. I guess, first step, don't panic. Second step, call somebody. [laughs]

Doug: Yes, I'm just thinking, is it acceptable to shoot a picture of something like that and send it along, or do you have to see it in person?

Chelsi: Yes. It's always helpful to see things in person, but plenty, like the technical advisors, so my colleagues and myself, we're pretty good at doing what I call digital diagnosis. A lot of times, Arborists will send us photos, but make sure the photo's not blurry. Especially if you're trying to do fungal photos, top photo and underside photo, because we need to see if it's got gills or pores or what the color is. We'll try our best, but yes, sometimes we do want to come out, especially if we think it's a wood decay pathogen, because those can be dangerous.

Doug: Best advice for homeowners to try to avoid decline in trees?

Chelsi: Yes. I'd say start before it starts. Beat the decline to the tree. If you are looking at your tree and you're loving the way it's looking, essentially, don't rest on your laurels. Check now to make sure, A, it's getting adequate drainage, it's getting adequate water. Really look into mulch if you don't have it. Mulch is one of the best things that we can do for a tree.

Then really consider anything else as far as encouraging beneficial microbes growing within the soil. That would be things like using compost, your mulch. If you want to go into biochar, that's great too. A lot of soil care and cultural care, it's easiest done preventatively. Start now, essentially, is what I would say. [laughs]

Doug: Well, great advice, Chelsi. It's always great to talk to you. Next time, though, it's going to be all fungus all the time.

Chelsi: That is the way I like it.

[laughter]

[music]

Doug: Thanks again, Chelsi.

Chelsi: Of course. Thank you.

Doug: Always such a joy to talk to Chelsi. She is just filled with enthusiasm. All right, you tree lovers, tune in every Thursday to the Talking Trees podcast from the Davey Tree Expert Company. I'm your host, Doug Oster. I need you to do me a favor. Subscribe so you don't miss a show, but we're looking for your questions. I would love to do a whole show with your questions being answered by an arborist.

There's a couple different ways to reach us. Just send us an email to podcasts@davey.com. That's P-O-D-C-A-S-T-S@D-A-V-E-Y.com. You can also click the link at the end of our show notes to text us a fan mail message. How about some questions? Send them in. It's going to be fun. We'd love to hear from you. As always, we'd like to remind you on the Talking Trees podcast, trees are the answer.

[00:17:48] [END OF AUDIO]