The Heartwood Problem

A tree can look solid for decades while the center quietly hollows out, and archaeology has a name for the confusion that creates: the heartwood problem. When you carbon date wood, you can end up measuring the newest layer instead of the oldest core, and the result can be wildly off. That one detail cracked my brain open, because it mirrors how we judge people, including ourselves. The outside is what everyone sees: the bark, the mask, the “I’m okay.” The inside is older, denser, and harder to reach, especially if you had to grow up too fast.

I walk through the actual tree science, from bark to cambium to living wood to heartwood, and then I use it to talk about trauma, shame, and the places we refuse to revisit. Fast-growing trees are more prone to heartwood rot; people who were parentified, pressured, or pushed into adult realities early can carry a similar risk in the form of unprocessed pain. We also go straight at moral injury, including the kind veterans live with, where the hardest memories aren’t only what happened to you but what you did to survive, comply, or make it home.

The way out isn’t pretending the past was fine. It’s building what I call compassionate narratives, pushing present-day understanding back into the oldest parts of your story until the rot stops spreading. I share a simple set of “tells” for real self-compassion, because intellectual insight is not the same as healing in the body: softness, slowness, breath, and tears matter. If you’ve ever felt broken, rotten, or beyond repair, this one is for you. Subscribe for more, share it with someone who needs a gentler mirror, and leave a review with the line that hit you hardest.

Transcript

Welcome And A Weird Analogy

SPEAKER_00 0:35

Hey everybody, and welcome back to another episode of the Speak Plainly Podcast, where we speak plainly about things that matter. I'm your host, Owl Medicine, best-selling author of Rethinking Broken, and host of this podcast. I do other weird things. I'm a musician, I'm lots of stuff, um, but mostly I'm just weird. And in this episode, we're going to talk about the weird places my mind goes because I love an analogy. Um I spend a lot of time just with my brain going weird places, like I think most people do. Uh, but recently I had this analogy

The Archaeology Heartwood Problem

SPEAKER_00 1:15

pop into my head, and I really like it. I really like the way that it makes me think about things. I saw some parallels, and the parallels are between people and trees. Um, specifically, this thing in archaeology called the heartwood problem. Have you ever heard of the heartwood problem? That's what we're going to talk about today, and how the heartwood problem is actually also really reflective of people. And in archaeology, it's really simple. It's that there is trees, and people make stuff of trees, right? Like there's a lot of stuff throughout human history that has been made with wood. And that's awesome. Wood has been super useful. We carve spoons and plates and like toys and all kinds of lovely, like useful things, wheels, water wheels, um, all kinds of stuff. We make things out of wood. And in archaeology, people who are very smart do a lot of testing of said wood things um to get there how old they are. And we like that. However, with trees, the outside of a tree is considerably younger than the innermost part of a tree. And so when these uh archaeologists are trying to age a um an item that is made of wood, they run into what's called the heartwood problem. When they are carbon dating it, they are actually dating these isotopes that are only found in the Cambian layer. And so when they date a tree to say, hey, carbon dating, this is how old the tree is, they're actually only going to the newest portion of that tree. So if a tree was a thousand years old, and that definitely happens, that tree can be cut down and used for a bunch of things, and the carbon dating will be a thousand up to a thousand years wrong because it's only it's only measuring the stuff that was in the cambian layer, which is the layer that's under the bark. So when you look at a tree, if you don't know what the cambian layer is, the parts that we see of like the branches and the and the leaves and whatnot, it is all covered in bark. Bark is the outer protective layer. And just like trees, people also have an outer protective layer. And depending on what's happening inside that tree, the protective layer can do different things. Like really soft trees can have like can have poisonous things, and like uh cedars and whatnot live in very wet places, so they have enzymes and stuff that stop them from rotting in their cambian layer and in their bark. But they have all trees have a layer, not all, but I guess pretty much all have a layer of of bark on the outside. Some are just a very, very thin layer, and it's just the cambian underneath there. So there's a protective layer, and then there is the actual living layer. That living layer is called

Bark, Cambium, And Tree Bacon

SPEAKER_00 4:30

the cambian layer, and the cambian layer can be used for food. In fact, um, it can be used for quite a few things. Um, it is considered a um like a it's not drought food, a like starvation food for natives. Um, if you find yourself lost in the woods, it was common in um North America for the natives to strip off chunks of the cambian layer and try to get some micronutrients from the cambian layer, break off some bark, cut off a strip, and get the good bits from the cambian layer. They call it tree bacon. Um, that's the living part. That's the part that when a tree is trying to live its little tree life, it has to pull all the nutrients up from the root, from the roots and take it up to the roof, up to the leaves and branches. And the way that it does that is by pulling moisture and all the good bits that come with the moisture from the roots up the tree. Now, if a tree gets extra, extra big, there's actually other ways that the trees can do that. You'll see that there's like mosses and lichens, and it'll make little communities and little ecosystems that will actually like act as way stations and like forward operating bases almost for the tree. But that's only when the trees get really, really big and trying to move liquid with that much gravity becomes difficult, and like evolution had to find a new way to provide those nutrients. But regardless of whether it's coming from the roots or from any of these little nodes, um the living part of the tree is underneath the bark called the Cambian layer. Underneath that, you have the living wood, which is the stuff that the is still kind of getting nourished by the tree. Um the actual living layer is only the cambian layer, but then they have like they call it living wood. Um, and then underneath that they have heart wood. Now, if you've seen a tree cut down, you can see that like the dead center of it is like it feels extra compact and it's really, really dense. And then there's like the regular layer, and then there's the very layer, there's the very soft layer underneath the bark, that's the Cambian layer again, and then there's the bark. So there's a protective layer, a living layer, the living wood, and then the heart wood. And this is interesting. So when you when you make a a spoon or whatever, and if you make it long ways, the end of that spoon could be a thousand years old, while the tip of the spoon is um is like a month old, which is kind of wild if you think about it. And it's it's like it's just a neat little archaeology thing. But what makes it really interesting is when you realize how much like people this actually is. So people also have our protective layers. And we all we

What Protective Layers Hide

SPEAKER_00 7:40

all know that. We all have the masks, the masks that we wear and whatnot. I certainly have a bark of my own. Um and we need that, we need a protective layer. And like I said earlier, it depends on what's happening inside, like deep down inside the tree, that um will tell us what needs to happen with the bark and in the protective layer. But it all makes sense within itself. Like the tree, there is a consistent theme and uh story within that tree. And when you look at a tree, you can't tell if it has good heartwood or not. You can't tell for sure. And that's also true of people. When you look at people, you can't always tell. You usually can't tell if they have good heartwood. But there are a few things that kind of make it much more likely that you have some rotting out heartwood or some heartwood that is not structurally um helpful. And the way that that happens is usually from growing up too fast, just like in people. So the trees that are most likely to develop heartwood rot are poplars and pines and things that are fast growing. Um, the poplars are especially they and and alders, they're soft woods, they grow really fast. There isn't there isn't shade to like protect them, and they are competing for resources to grow as fast as they can. Now, everything in biology and in life is a trade-off. And so if you are growing faster than everything else, that also means that you're not going to grow as dense as everything else because you are worried about trying to grow up and grow down, trying to get enough roots to establish yourself and get up high enough to collect enough sunlight to be able to run yourself. And a lot that can look different for everybody. A lot of times it can be the parentified child or something like that.

Growing Up Fast And Rot Risk

SPEAKER_00 9:55

But you never really, really know what's happening inside. But you can look at a poplar and be like, that had to grow fast. This whole species grows fast. And when you grow fast, that means you typically you run a higher chance of the heartwood rotting. And this is where I think the analogy gets interesting, is because the way that the heartwood rots or not is essentially that cambian layer is still moving goods into that living layer of wood. It's still moving all of the stuff that the tree needs for life into the other parts of the tree. And so, even though the cambian layer is the only living layer, after the cambian layer has moved inward, it's gone dormant, and we've had a winter, and the next year starts, that cambian layer will then like condense a little bit, it moves inside, and then another layer is built on the outside of it. Now, that next year, you have a new cambian layer, but then you have this inner living wood, this inner wood that's still kind of soft. And the tree will continue to feed that softer layer. And if there is a particularly good year with lots of sunlight and all the nutrients that the tree needs, then the tree can actually kind of push a little deeper with the goods, the blood of the tree that's in that same that cambian layer, the kind of sap, if you want to call it that, push it much further into that living wood. And it can it can make that living wood more dense even after it's no longer the Cambian layer. And this is the cool analogy to me. This is also true in people, because there are people with rotten hardwood and heart wood, and what that means is that there's a thing inside them in the past that they let rot. There's a piece inside them that has crumbled and at it atrophied down to nothing and it crumbled out and fell out. And if you're like me and you've spent so much time in the forest, you've also seen trees that have majorly rotted out that still grew absolutely massive. So it's not saying that a person who has some rotted out

Feeding The Past With New Sap

SPEAKER_00 12:30

hard wood is a terrible person or not valuable or any less. I think they're actually more impressive in many ways, and we'll get to that. The the reason in the that this happens, the living wood doesn't push the sap and things deep enough. And for the human being, what I view this equivalent as is are you reflecting on your life? Are you reflecting on your choices? Are you reflecting on the things that have happened in the past by you and to you? Have you looked at those things and given them consideration and fair thought and maybe a little grace? Have you really tried to push who you are now? Because we're all typically trying to be a little kinder, a little nicer, a little a little more fair to ourselves. Have you actually been pushing that into not just your current moment, but into the past occurrences of yourself, into the past situations? And if you do, that's kind of to me the equivalent of pushing that that tree blood, that sap deeper into your recent past, and finding ways to view yourself as okay, and to view the parts of you that you maybe aren't that proud of as okay. The people I think of the most when I think of this are like old Vietnam vets, and that's probably because of my age, but there are people, specifically, military is a very easy place to go where these people had to do things that are not well, they're just not suitable for human life. I think taking another person's life, especially doing it as a kind of career for any length of time, is not a thing

War, Moral Injury, And Justifying Pain

SPEAKER_00 14:40

that really fosters life. Taking another person's life does something to you, and it's not a good thing, and it makes it hard to live after that because you have to justify it. You have to justify it one way or another. And it's theoretically justified when you join the military, right? It's that you're protecting you're protecting your country, or you're protecting the guy next to you, or you're protecting democracy or some other bullshit lie. But regardless, that is the that is the belief moving into it that you're protecting these things, that there's a reason for it. But then when you actually do it, it it hits real, real, real, real different. And that does something to you. And as you grow, you know, and these these are 18, 19, 20-year-old children that join the military and do these absolutely horrible things. And that's the things that happen to you when you're young, that's that's the stuff that becomes heartwood. But if you can't find a good way to justify it, if it feels so awful that you don't or can't bring your mind into those experiences later on to bring that sap and the attention and the compassion for oneself into those oldest parts of us, the parts that we hate the most, the parts that seem intolerable. If we don't if we don't shine the light of compassion, send that sap down from the Cambian layer into our heart wood, then because we had to grow up so fast, those like no 18-year-old or 20-year-old or anybody should be having to kill, but that is a thing that we can't escape in this natural world. Um at least we haven't been able to up until very recently. That's something that it it leaves that can be in layer. When you're that young, it leaves it so soft and spongy because you had to grow up. And you can't change that. You can't change what happened to you, and you can't change what you did. But you can change your narrative about it. You can change your perspective on it. And when you do and you allow yourself to see a different narrative and a different perspective, and you s you do that with compassion, what I call compassionate narratives, reframing things with compassionate narratives, then you can push that sap deep into your heart into the places that get no love, they get no affection. And you can restore that so long as you're not too far away from it. But if you're in your 70s or 80s and you're one of these Vietnam vet types, or you just had kind of a more hard life, the the distance from your cambian layer to your heartwood is much greater. And for these people, the thing is is heartwood rot, when that heartwood rot starts to happen, it will continue to grow. It can start just just a little seed in the very center of a tree, and it will continue to grow and continue to grow, and while the cambian layer is also continuing to grow. And we see that a lot in fruit trees, in fruit-producing trees. Um, if anybody has any orchards or been to one, you'll know that all the plums and apples and whatnot, they've got all these funguses and they're all splitting and they barely have any kind of living tissue, but they still seem to be producing producing fruit on occasion. Fruit trees are really good at that. They will rot out and be growing new tissue at the same time. And that's almost it feels like the life of an artist or something, because it's like having that those negative, those negative narratives chase you and constantly provide you with the the impetus to create. And each thing that you create allows you to live a little bit

Fruit Trees, Artists, And Being Chased

SPEAKER_00 19:10

longer. And I mean, it almost feels like the terrible 27 thing of like there's a rotten, there's a rotten beginning, a rotten, a bit of rotten heartwood that's chasing this person because there's some belief inside that says that there's this part of them that doesn't deserve love. This is why I wrote Rethinking Broken. There's a part of us that we believe is broken, a part of us that we believe is rotten, and if we believe that that part of us is broken or rotten, if we're broken, we'll never be able to rise above it, and if we're rotten, we won't be able to outrun it. So we use the that impetus and that um catalyst from being chased by our own rot to create magnificent art, and that art is the fruit. But there is an interesting thing that happens with heartwood that has rotted and then stops when they measure the density of the of where the heartwood stops and that living wood or stops rotting, and it either becomes good heartwood or becomes that living wood. The edge of that rot is extra dense. The very edge of where the rot reached and stopped becomes incredibly dense, and it has to be really, really dense there in order to stop the rot. And to me, that is the psychological equivalent of recognizing I went to war and murdered innocent people because rich people told me to, and I was too dumb and young to know better. And genuinely finding those compassionate narratives and really truly believing them in our heart of hearts, knowing that yeah, we fucked up, but we did everything that we could to the best of our ability, and the best of our ability maybe even wasn't good enough. But in order to stop that rot from chasing us, we have to harden the edges around those experiences. Because sometimes it's about coming to terms with horrible things that happened to you. It's much, much, much harder when it is horrible things that you did because of the horrible things that happened to you. So for anybody who is in that situation right now, who is struggling with the what I did, there is always a biological explanation for every reaction that we have that is biologically logical to do ridiculous, over the top,

Stopping The Rot With Compassion

SPEAKER_00 21:55

seemingly crazy, aggressive, violent, whatever things. Are biological reactions, and that doesn't mean that they're the right reaction or appropriate or something that you want to do or ought to do, but they are understandable. Emotions are logical, even the stupid ones, they're just not rationally logical, they're biologically logical. So I hope you can find some kind of compassionate narrative for yourself. I hope you can find some way to describe what happened to you or what you did in a way that is compassionate to yourself, that doesn't perpetuate the idea that you were broken and that or that you were rotten, or that there is a part of you that needs to be fixed. Maybe there's just a part of you that had to do horrible things in order to survive. And you wish that you could have done differently, you wish you could have behaved differently, you wished that you knew then what you know now. If you actually let yourself move into that place and feel that emotionally, then you will be able to find some peace. But here's the thing about self-compassion it's really hard. It's really hard for those of us who were parentified. It's really hard for those of us who have just had to keep it moving our whole lives. So I want to give you some milestones, some some goalposts to let you know if you're actually being compassionate to yourself. Because as a person with my own story, I have a terrible, terrible time being compassionate to myself. So I created these for me. Use them if you like. If it's me having a conversation with myself and I'm trying to find compassion, I have to be speaking very softly, and I have to be speaking very slowly. My breaths are very long, my voice is quite soft, and most importantly, there will be tears. There will be tears. If there are not tears, I did not touch that inner part of me. If there are not tears,

Signs You Reached Real Self-Compassion

SPEAKER_00 24:30

it was practice. It was a r I was it was running up to the edge and pacing and getting things set up, and maybe maybe that's what we need. Maybe we need to practice running into this, running into these places. But unless you actually spend time sad, soft, and sobbing, you did not access compassion for that part of you. It's going to be hard. It's going to be really hard. Because typically, if it's something that we've done, we have an idea of ourselves that we are good. And we are, you are. But trying to rectify doing something bad as a good person doesn't neurologically make sense. It creates a lot of friction, and we don't like that. So you will have resistance, you won't want to do it. You will you will feel like you did good enough, but if you didn't do it soft, slow, and sobbing, you did not actually reach that heartwood with compassion. So this is today's episode. I hope that you got something interesting out of the heartwood problem. I r really enjoy a good metaphor or analogy or whatever the difference is. I think I looked it up recently, and one's like if I say you are a river, or I say that you're like a river, one's one of those and the other one's the other, and I don't know which is which, but that feels like a real dumb differentiation to me. Regardless, if you like my meta-analogy, then hopefully you'll be able to share it with somebody. Send this episode to somebody who is struggling to accept parts of themselves or parts of their life. We all have so much underneath what we see, you know? And most of the time it's not until a tree gets cut down at the end of its life that we see the heartwood, that we see what's deep inside. And the most amazing trees to me are not the ones who grew the densest and the most perfectly hard. They had, well, the perfect environment to do so in. Their natural inclination suited their environment. And for some of us, the environments didn't allow that. We competed too much for too many resources, and that's okay. So if you had to grow up a little too fast, try to find a little extra compassion for yourself this week. And remember, stay curious and stay uncomfortable.