Orchard People

#073 ORIGINAL Being a Tree Detective with Lindsay Mitchell and Sarah Ruark
[00:00:00] Introduction and Simple Joys
Susan: Sometimes it's the simple things in life that make us happy, like a relaxing walk through the woods or biting into a homegrown apple, fresh off the tree in the fall. But as the weather gets colder, lots of people enjoy curling up to read a good mystery.
Usually the mystery revolves around a murder. What if? What if that mystery involves a tree? Maybe the tree has suddenly gone into decline when it was perfectly healthy just months beforehand. Maybe it's a fruit tree that suddenly stops producing fruit.
[00:00:39] Introducing Detective Dendro
Susan: That might have been something that the creators of the Detective Dendro series had in mind when they created this series of educational mysteries that you can find in the International Society of Arboriculture's bimonthly magazine, Arborist News.
In this wonderful series, Detective Dendro travels around the world to investigate tree mysteries with his sidekick, Codit. Each issue, I love to read about the good detective's latest adventure. It always makes me think that anyone who grows fruit trees and other trees can find joy in becoming a tree detective.
When we're curious and attentive to our trees and how they change over time, we can discover potential problems and resolve them easily before they get out of hand. So in today's show, I wanted to feature some of the talent behind Detective Dendro.
[00:01:39] Meet the Guests: Lindsay Mitchell and Sarah Ruark
Susan: My guests are Lindsay Mitchell, the managing editor at the International Society of Arboriculture, and Sarah Ruark, technical advisor at the Davey Institute, the research arm of Davey Tree.
Sarah is actually one of the Detective Dendro writers and a tree detective in her own right. But before we dive into the show, I would love to hear from you, have you had a tree mystery, that you've had to solve? Or have there been some mysteries that have left you baffled?
So let's start with Lindsay Mitchell, managing editor of Arborist News. Hi Lindsay, welcome to the show today.
Lindsay: Hi, Susan. Thanks so much for having me.
Susan: I'm so glad you're here because we are gonna talk about my hero, Detective Dendro. And honestly, I love reading the stories every couple of months.
They're so much fun. Now, detective Dendro's name comes from the word dendrology. What is dendrology?
Lindsay: So dendrology is the scientific study of trees. We wanted to use that to tie in the detective's purpose. And also Detective Dendro series loves alliteration, so that Detective Dendro pairing was so on brand for what we were trying to go for.
Susan: So tell me a little bit about the good detective's personality. So what is he like as a character?
Lindsay: So he is, I think, fueled a lot by just a love for trees and an admiration for them. Everywhere he goes around the world, he usually finds something that he can admire, whether it's a particular local tree, or the the backyard or the garden of the client he's visiting.
And he's also a teacher. He'll always jump at the opportunity to instruct his assistant Codit in whatever they're looking at. Codit is the foil for Dendro. He's an inexperienced but very enthusiastic diagnostician himself, and he'll typically jump to the first conclusion that comes to his mind, which gives Dendro the opportunity to get him to dig a little deeper.
And I think that is also what we're offering to our readers as well is to look further than just the surface level. Dendro is just a very cool cucumber kind of guy. He's not ruffled by much. He's definitely evolved a little bit over the years. There are some fun details that we don't get to pull into the stories very much anymore. But for example, Dendro absolutely loves onions.
Susan: It's funny that you say that because it's very cute, like in each mystery, Detective Dendro as well, I just got a call from Texas and it's a really important issue about a tree, and I heard they have really good food there.
Like he's all about food, the local, famous dishes and things like that. So he's got this wonderful, funny character that I really like. So what is your role? You're the editor, and I understand that different people write the Detective Dendro mysteries each month. So what role do you play?
Lindsay: So I am primarily a coordinator. My main task is finding people who not only are qualified to write these stories, but also who are willing, who love the format. And I work with them to help them focus a topic or a mystery. And I also, once I have a draft in hand, I'll spend some time making sure that the story flows, that the dialogue is very present because the dialogue is an enormous part of the stories and what makes them work. One of the things that we have to make sure, is that the information that's packaged within the story is accurate and useful. So all of these articles, because they do have a technical aspect, they do receive an external peer review from other subject matter experts, and that is also something that I coordinate.
Susan: Okay, so tell me a little bit, can you give me one of the stories? What kind of story would we encounter in Detective Dendro?
Lindsay: One of my favorite stories that, it was actually one of the first stories that I edited when I first came on board with ISA, was the Case of the Christmas Catastrophe, which I believe was in the December issue of 2018.
That was written by James Komen. He actually used to be our primary writer for Detective Dendro. Really excellent stories. And in that story, Dendro and Codit go to visit a friend's house for the holidays. He has just done up his whole house, his yard, just almost every light and inflatable you can imagine.
And while they're visiting, a tree branch falls on the house. And so Codit and Detective Dendro go out back and they try to figure out what's going on, and they have this just enormous tree that is all wrapped up in lights. And it turns out the tree owner had never taken the lights off of the tree from season to season, which had caused some girdling issues and a branch had died.
There's some dialogue in that story that just made me laugh out loud. If I remember correctly, the tree branch falls on the house and Codit looks up and goes "Santa?"
Susan: That's very cute. And of course Dendro would be, it's elementary, my dear Codit. Yes. So girdling, which means that the string of lights was too tight on the branch.
And the branch was squeezed and got weak. I guess Sarah can explain that to us a little bit more. Actually, Sarah, can we call you in on that? Would that really cause a tree branch to fall having a ring of lights around it?
Sarah: The most important part of the tree is really just under the bark, which is where the vascular system is, what's moving water and nutrients all throughout the tree. And so when you start to get girdling, say from string lights being wrapped around, then you're killing those cells that are so important and cutting off the circulation, you could think of it.
Susan: That makes sense. If I were to tie something very tightly around my arm, I guess my arm would wither. It would not do very well if it couldn't get the blood. And I guess it's similar with the tree branch. Lindsay, what other kinds of mysteries might we get in Detective Dendro?
Lindsay: They cover just about every problem you can think of. We've had articles on tree injection practices, we've had articles on fungus. We've had articles on performing a proper pre climbing inspection. We have a lot of articles that cover insects and other diseases. And so you can find just about anything that suits your fancy in the broad scope of articles, going back all the way back to 2004 when the series first started.
Susan: How about, now obviously in this show, we're very interested in fruit trees. Have they been covered much in the series and can you remember any stories?
Lindsay: They haven't been covered quite as much, which I think is a wonderful opportunity for moving forward.
But we do have an article called the Avocado Aficionado, in which a gentleman is trying to grow avocado trees in his yard, in his neighborhood, in a more or urban setting, and they just won't bear fruit. They seem to be in good health. The flowers all look good. But no avocados are growing. So Detective Dendro and Codit come over.
They inspect the trees, everything looks fine. The usual diseases that you might see in avocados are not present. And then they discover that there are apparently two types of avocado trees, a type A and a type B, and they both go through male and female stages, but at different times of the day, and the client had only planted trees that were all male or all female at the exact same time, so they weren't pollinating each other at all.
Susan: Wow, that's a big one. Oh my gosh. And especially with fruit trees where a lot of fruit trees, you don't necessarily have male and female, but you need two different varieties in order for them to produce fruit. And I have had people come to me and say, I planted a plum tree seven years ago.
Seven years ago, and I can't figure out why it doesn't have any fruit. And they didn't do their research to figure out that these plum trees need a pollination partner. So if there is not another compatible plum tree anywhere nearby, there is no opportunity for pollination to happen, right? Unless you get a rogue bee coming from miles away with a little bit of pollen on its little bee parts. Yeah, that's a great story.
We've got a couple of emails here. So this one is from Joyce. Joyce writes, wow, what a concept. Brilliant. I'm listening from Jackson, Wyoming. Better than Sam Spade. I like that. Yes, definitely.
We've got another one here. And this is from Susan in Ontario, the nine apple trees in our community gardens were defoliated by gypsy moths this spring but put out new leaves, but had few or no apples this fall. Is this a normal reaction to being stripped bare? And will they most likely produce next year? I think our resident detective is a good one to talk to about that. Sarah, do you have any comments on how these gypsy moths and the defoliation might have affected these apple trees?
Sarah: A tree, as a living organism, needs to be passively making decisions about where the energy goes, and I think defoliation is removing the leaves, which is how the tree produces food and energy for itself. And so the priority would go to refoliating rather than fruiting, to try to save itself. It's not a conscious decision, but sometimes it's easier to talk about trees as if they can make these decisions for themselves.
But I would think that's most likely what happened is all the energy got redirected, making leaves for photosynthesis. And I do think next year, it should be back to normal if it has all its leaves.
Susan: We've got another email here from Edward. Ah, okay. So Edward writes, hello. What exactly is tree blight?
Thanks. Okay, that's a good question for you, Sarah.
Sarah: Blight is a very general term that could describe a lot of things, so I don't know. Typically you think of a blight as a disease, a pathogen that's infecting the tree, but without getting any more specific, I am not sure.
Susan: There's lots of fruit trees, gets lots of different blight like fire blight and there's so many different diseases. I teach a course called Fruit Tree Pest and Disease Management, where I teach people for each fruit tree, there are probably five to seven common diseases that you get all the time. And if you know what they are, you know what to look for in advance. So that's my own personal way of being a Detective Dendro, is to prepare. Be prepared. So actually back to you, Lindsay. I understand that you have actually written one of the stories. How did that come about and what was that like for you?
Lindsay: I wrote a story about, the woolly bear caterpillar. I wrote a story about a gentleman who had a previous infestation of bagworms and saw a caterpillar on his precious trees, freaked out, and called the detective over right away, just to be sure, and so was able to educate about. It's a harmless creature.
They don't actually spend much of their time on trees at all. And it was probably more of a nice highlight for the caterpillar than the trees, but I had a good time writing that.
Susan: So we've got another email here. It's from Nan. Nan writes, enjoying the show. Hello. Enjoying the show today from London, Ontario.
Kudos to your guest. Thanks. Thank you, Nan.
If arborists want to learn, or if people want to learn about trees, fruit trees, or any kinds of trees, they could actually just go to the university extensions. They can look up whatever disease they wanna learn. Why is this different? Why do you think this is more helpful somehow?
Lindsay: I think it's a great companion to those fact sheets. I think obviously we wanna encourage people to look at those resources in addition to reading things like Detective Dendro. But my personal idea on why Detective Dendro works so well as an educational model more than just entertainment is, stories have a way of sticking into our minds.
There are so many study techniques out there that involve coming up with creative connections, or telling yourself a story to try and remember that information. So if you got a laugh out of a Detective Dendro story, or you remember jumping to the right conclusion before you turned to the end of the newsletter, I think that that would stick in your mind. And if you came across a similar situation yourself, you might remember, aha, I remember that story that I enjoyed so much. And you could actually bring that forward into your practical day to day.
Susan: And we have another email here from Hank. Aha, this is a great question.
Hank writes, and this is his mystery. Hello? Can we prune our trees now into the fall? I live here in the GTA, which is the Greater Toronto Area. Sarah, can I ask you to answer that question?
Sarah: I was going to defer back to you because you live in Canada. I'm based in Texas, so I wouldn't wanna give the wrong advice for your neck of the woods.
Susan: Absolutely. I will definitely answer that, and we do not encourage it. So our concern is if you prune right now, Hank, before the winter, it may spur some new growth in the trees. So let's say you prune your tree, you get a little bit of new growth and the new growth is tender. And let's say there's a frost.
The new growth then will break and snap, and that becomes an entrance point for pest and disease problems. So I know here in my orchard we finish all our pruning before midsummer for sure. Just like we don't fertilize after midsummer, we do not prune. So here's what I would suggest, Hank, not sure what you're growing.
But early spring or late winter is a terrific time to prune because at that point, soon it will be springtime. During the spring, the tree will be able to heal itself. It will be coming back to life, and it can heal itself. Whereas in the winter, it's not really growing that much, so it won't be able to heal those pruning cuts.
How do you feel about that, Sarah? Yeah. How did I do as a tree detective?
Sarah: That makes sense to me. It's very different here in Texas. We usually don't have a harsh winter like you have in Canada. So we don't normally think about those kind of things.
Susan: Yeah, we've got lots to think about.
Shoveling snow, salt from the streets that goes on our gardens. Oh my gosh, we have lots to worry about. I gotta come visit you guys in Texas.
/ Sarah, I wanna talk with you a little bit. About your five steps to investigating a tree mystery.
How do you, and we'll talk about this, what are the steps you take when you are investigating a tree mystery, a tree problem, and trying to diagnose it and figure it out.
/ So in the first part of the show, we spoke to Lindsay about Detective Dendro, this wonderful fictional character that solves tree mysteries. Now let's speak to Sarah Ruark, who's one of the people who writes the Detective Dendro Mysteries. So she is technical advisor at the Davey Institute, the research arm of Davy Tree.
So tell me a little bit what it's like to write these Detective Dendro mysteries. Do you just come up with ideas, out of whatever, just make up ideas as you go along?
Sarah: I will say, I come from a scientific background.
I have a master's degree in plant pathology and so I'm used to much more technical writing. So writing Detective Dendro is a little bit of a stretch, and that's where Lindsay is very helpful, especially when it comes to the dialogue and stuff. But, unlike her issue with the story she wrote, where she had to really think about what topics she felt comfortable covering. Because I encounter so many mysteries and trees every day in my job, it's easy to just pull the more interesting ones. Or a lot of times maybe I'll choose one based on what I have the best pictures of, because we do include pictures with these stories. And so that will usually gimme a general idea what I wanna write about.
And then, usually I have to embellish it because the detective needs to have a good, clear solution at the end of his stories. A lot of times for a real detective, it's not that easy.
Susan: Okay. So give me an example of one of the stories that you wrote, whether it was based on a real world experience or not.
Sarah: So the most recent one I've written was The Case of the Rowdy Rooftop. And this was about an actual rooftop garden that I visited. They had this Japanese garden. It was maybe 60 years old, established on the roof of this condo building in downtown Houston, Texas. And they had quite a few insect problems going on up there, but the treatment was complicated by the presence of a very large koi pond.
It took up the majority of the center of the garden. And so it, you couldn't apply any pesticides or anything, because of the risk of running off into the koi pond. And so I had the detective try to come up with an innovative way to control the pest problem that would also, protect the safety of the fish.
Susan: Okay. So tell us, we wanna know. Unless a listener knows the answer to that question, I would love to know.
Sarah: So in the end, the detective proposed using beneficial insects or predatory insects, to target the insect pests that were present on the garden. And in fact, in real life, that is what I proposed.
Now in my story, the garden manager was very happy with Detective Dendro and said, oh, that's a brilliant idea. I'm excited to try it out. I may have encountered less enthusiasm in the real world situation.
Susan: I'm guessing that in Detective Dendro, you always have your customer or the client is always very supportive of the detective's ideas and his wisdom.
But I guess in real life it's not always so easy. Do people have strong opinions as to how to care for their tree?
Sarah: Usually, yes, especially like a situation like that, it's a condo association. There was a whole group of board members that were gonna need to sign off on any decision. The garden manager even said it took us over a year to decide which color to paint the bridge. So yeah.
Susan: Challenging. Now you did another story, I'm pretty sure. Was it another story on palm trees? Am I right? Yes. So tell me a little bit about that one. That was interesting as well. That was another real mystery.
It's Ooh, what's the answer to that one? I'm like, I can't even guess.
Sarah: That one I thought would be a good one to stump the readers because it was a very unusual situation that occurred in real life in Texas this past year. And I also wanted to take that opportunity to share what was going on in Texas with a broader audience.
So it made some news headlines last February. I'm not sure who all heard about it, but there's a very severe freeze that hit all of Texas all the way down to the Gulf Coast and that lasted several days. And of course we are not used to winter like that and neither are the trees. And there are a lot of palm trees and other tropical plants that are grown here that couldn't tolerate the freeze.
So I decided to write a story on that where the detective would come from out of state. I had to come up with some way that he's been just so focused, laser focused on what he was doing. He missed the news story about it. He's just visiting Texas for fun. And then why are all these palm trees dead?
Because I would estimate, at least in Houston, 70 to 80% of the palm trees died from the freeze. And so I have the detective encounter as he's driving from the airport, all these dead palm trees. And he is trying to piece together what could be happening 'cause it seems to be spreading among different species.
And then in the end he also sees what's commonly referred to as a sago palm. That's actually not a palm tree at all, but another genus. It's also dead. And then that's his big aha moment is, oh, it must be environmental because it's crossed not just species, but even between genre of plants.
Susan: Aha.
So this is fascinating because we get a glimpse into what his methodology is.
So when you're reading these stories, he comes out with these bits of wonderful knowledge and you think, how does he piece this together? But when you and I were chatting earlier, you said, oh no problem. It's a five step process diagnosing.
So please do share with us what is the secret to diagnosing problems, whether it's fruit trees or other trees.
What are the five steps that you go through when you encounter a real life tree mystery.
Sarah: Okay, so what I've found works best for me is yeah, this five step process and probably you ask another tree detective or plant detective, they'll have their own, but for me, yes, I start with the one we talked about already, which is to identify the plant. It just really helps to know what you're looking at. That kind of gives you a direction to go in.
The second thing would be to look for symptoms or signs. So symptoms are going to be, what is wrong with it. Maybe there's something very obvious. This tree, all the leaves have turned yellow and it feels like, okay, I know what the symptom is.
But I would encourage at this step to really closely examine all parts of the tree that you can see, and maybe even try to see what might be going on with the roots, because that's important. And of course, signs would be evidence that there's a fungus growing on it. Maybe you see a mushroom or the presence of an insect, maybe you see a borer in a hole or something like that.
My third step would then be to notice patterns in the landscape. So very often I'm investigating, a prize tree that's the center of someone's landscape in their backyard. I wanna step back and not focus in on, I'm here to see the tree, but what else is going on in this yard? How do the other plants that are planted here look? What does the grass or the turf look like?
Maybe you start to see a pattern. Oh, everything on this side of the yard that gets more sun is looking similar. So this might not be a problem just with this tree, but more something environmental that's affecting this side of the yard.
After that, the fourth step is to ask questions.
So I think of this as I want to write a biography of this tree. I wanna know where it came from, how long has it been here? What has ever been done to it? What has it experienced? What was it like last year? And this is where your experience really comes into play to help learn which questions you need to ask.
But really, you just wanna know everything you possibly can. Once I've done those four steps, the fifth step, if I think it's necessary, is to try to collect a sample and send it to a lab. See if they can detect something that maybe isn't obvious or clear just from a visual inspection. Or maybe I just get on the internet and say, I'm gonna just search.
All right, I at least identified it's this kind of tree. What kind of problems are common with it? And maybe that will help me get an idea to revisit some of the previous steps.
Susan: So you gather your information in your investigation, and you're putting the pieces of the puzzle together.
And I think for me, the biggest lesson is always to think of trees. It's not like humans where pretty much every human can get pretty much every disease out there. But trees are very specific in the kinds of pests and diseases that are attracted to them. So that narrows it down so much, doesn't it?
That's wonderful. So there you are with your five step process. There was another story that you told me about on the phone and it had to do with roots. Now you can't see roots. So tell me the Detective Dendro story where he figured out right away that this is a root issue.
Sarah: / I think the detective did have a story about this.
It wasn't one I've written, but I had a story. I solved this one. Yeah, root problems are very difficult because the symptoms are very similar to a lot of other problems, and there's no way usually with a tree to inspect the roots directly. And I was on a property, the client was concerned. Their tree was just not looking vigorous.
It was just wilting and yellowing and he wasn't sure. And really, even before I had closed the car door, I said, how moist is that planting bed it's in because it was in a planting bed with a lot of flowers and stuff right next to the house. And he says, oh, it stays pretty saturated here.
And sure enough we went and it was almost a pond. And I said, I think this is probably a Phytophthora root rot because Phytophthora is an organism that loves water. It actually has spores that swim. You'll often encounter it in areas that remain wet for long periods of time. But the only way is with a lab test.
But yes, that was my suspicion.
Susan: And how many minutes did it take you to diagnose that issue?
Sarah: That was a very lucky day. It was like within the first minute I said, let's just check soil moisture. And sure enough, it was saturated. Now, of course, to confirm I was right, we would've had to collect a sample and send it to a lab.
But really the underlying causes, let's get rid of this excess water and let the ground dry out.
Susan: And when it comes to trees, how often is it our fault? As the humans who take care of the trees, how often do you encounter and what are common things you encounter that we do wrong?
Sarah: So again, my focus is usually on trees that are in people's yards.
So in general, this is not where trees evolved to live in a perfectly manicured lawn. They're more accustomed to a forest where they're protected with other trees. There's a lot of leaf litter working back into the ground and regenerating the soil. It doesn't occur in your yard. So most trees I see are stressed for one or more reasons, just because they're not in a forest.
I would say the biggest, most common mistake I see is construction damage. We've put in a new patio, a pool, a driveway, a whole house, and not taken enough consideration for the damage it's doing to the root zone of the tree. We just know I want that really pretty tree right next to the pool or right in front of my house, and it's roots have been severely damaged by all the construction activity.
Susan: So what is your advice, as someone who's passionate about trees, for all of us to do to care for whatever tree we have, whether it's a fruit tree or a native tree. What would you like to see the public do in terms of taking care of their trees?
Sarah: I think, in general, if you have established trees in your yard, it's just to watch them.
Nine times out of 10, I'm called to a client's house. This tree suddenly died. According to them. And I get there and I say, oh, this tree has clearly been in decline for a long time and you you've noticed now because the whole thing has died. But this was a long process. So to really carefully look at your trees on your property I think is something I would encourage everyone to do.
And the second thing would be, if you're planning a construction project, have an arborist come out and give their opinion before you get going with the construction.
Susan: That's fantastic.
Sarah: Protect the tree before this construction begins 'cause there's very little we can do once the damage has been done.
Susan: So how can people, how can listeners read these stories, and enjoy them?
Lindsay: Detective Dendro is published exclusively in Arborist News, ISA's member newsletter. So in order to read any of the articles within a calendar year, a present calendar year, you do have to be an ISA member. But, all issues of Arborist News, after that year, become freely available to the public.
So anything, for now, from October 2020 and before, you can go online to the ISA website and read on the Arborist News page.
Susan: Okay, so they Google, ISA Arborist News, and then you can go in and anybody can see the stories. I highly recommend it. Lots of fun, and it is just a great way to learn where you don't even feel like you're learning.
And Sarah, any last words from you about our hero, Detective Dendro?
Sarah: No, I do look forward to writing some more stories for him to solve because it is a satisfaction that he always has the answer. And so I need that sometimes, especially, if I've had a series of mysteries that I couldn't directly solve.
Susan: We all need him in our backyard helping us all out, so that's great.
[00:32:52] Conclusion
Susan: / Okay. thank you so much to both of you guys for being on the show today for introducing my favorite detective, and I really look forward to seeing some more stories. More on fruit trees, please.
I would love some more on fruit trees. Certainly. So hopefully Susan, you can write one too, maybe? Oh no. Oh my gosh. I would love to actually. That would be really fun. Okay, we'll talk about that. Yes, that would be quite fun. I could write a few of them about lots of ideas. So thank you very much for listening to the Urban Forestry Radio Show and podcast.
I am Susan Poizner from orchard people.com, and I look forward to seeing you guys again next month for a new topic. I'll talk to you then. Bye.