The Washington Monument Mulberry

This Old Tree with Doug Still
The Washington Monument Mulberry - Transcript
Season 3, Episode 8
August 10, 2026

You're listening to This Old Tree, the show about heritage trees and the human stories behind them. We're a sponsored project of the New England chapter of the International Society of Arboriculture, with generous support from the Pobble Stone Foundation. 

Doug Still
Picture yourself visiting Washington D.C. and walking the National Mall. Like a magnet, you're drawn to the Washington Monument, and you stroll up the gentle slope to the austere four-sided tower. The landscape is austere too, with no shade or vegetation taller than grass to speak of, except for one… lone…tree. You approach it to find a small tour group fixated upon it, led by a man asking questions. You eavesdrop.

Sam Nelson  00:47
Let me ask you all: What do you all think about the tree? What do you think of this tree? 

Tour Member
I think it's a very interesting shape. You know, it doesn't go straight up; it goes at a 45 degree angle. 

Sam Nelson
It does. Yeah. 

Tour Member
How did it end up? How did it end up that way? 

Sam Nelson
It's a bit of a mystery. This is a mystery tree. There's a lot of mysteries about this tree. The other mystery is if you look around the Washington Monument, what do you notice? 

Tour Member
It's the only tree here. 

Sam Nelson
It is the only tree here.

(narrative)
Doug Still  01:12
That is Sam Nelson, writer, educator, and proprietor of Tree Stories LLC, which offers guided tree tours among a list of educational offerings centered around trees and experiential learning.

(tree tour at the mulberry tree)
Sam Nelson  01:26
I heard you say it looks like it got blown over by a storm. 

Tour Member  01:29
Yeah.

Sam Nelson  01:30
Yeah, it is interesting. Do you think it's one tree or two trees? 

Tour Member
It looks like two trees. 

Another Tour Member
It looks kind of like two trees. 

Sam Nelson
Yeah, these are all like… I hang out by this tree a lot, and these are all comments I hear from folks like,  “That tree looks like it's in dire shape,” or… but actually this tree might be one of the oldest trees in Washington D.C. It's a complete theory. It's a little bit of a mystery. No one's sure.  

(narrative)
Doug Still  01:50
Sam is zeroing in on questions I’VE wondered about for years when visiting D.C., because I’ve noticed it too.  In this perfect landscape with its geometrically measured curves, the tree is beautiful and asymmetrically placed, like the mole above the lip of Marilyn Monroe. 

What the heck is this tree doing there next to our world famous icon, the Washington Monument? How old is it? Does it have any connection with the history of the National Mall? It’s clearly some sort of mulberry, but what type? Was it planted, or just a weed? It’s roped off and protected, with supports propping its trunk now leaning at a steep angle after it had fallen. Actually, ONE trunk is supported, while another stands next to it, straight and tall. Is it one tree, or two?

Then one day I met Sam through the wonders of Instagram direct messaging. We chatted about this enigmatic tree, its story probably lost in time. I told him that if he can find the tree’s history, I’d bring him on the show and give him the title, D.C. tree correspondent. 

Well, he did it. Sam’s research led him to find a landscape survey report written in 2014 buried in the proverbial vaults of our Nation’s Capitol. It was a government commissioned piece written by Jonathan Pliska, a landscape historian and author of “A Garden for the President: A History of the White House Gardens” published in 2019 through the White House Historical Association. Turns out, Jon left no stone unturned in researching the mulberry. He was THE person to speak to, and Sam tracked him down and landed an interview. 

So, I am gonna just step aside and share their conversation where they uncover the tree’s secrets. Turns out this individual tree is more important than I imagined. 

[This Old Tree theme music]

In celebration of America’s 250th birthday this year, please enjoy the conversation between D.C. Tree Correspondent Sam Nelson and historian Jon Pliska about the Washington Monument Mulberry. I’m Doug Still, and this is This Old Tree. 

[Piano music - Gottschalk]

Sam Nelson  04:55
All right. Here we are.

Jonathan Pliska  04:57
Here we are.

Sam Nelson  04:59
Cool. So, my name is Sam Nelson. I am what I like to refer to as an educational arborist. I was a teacher for many years, but I became an arborist, and I love telling stories about trees. And I've got my own very small, unprofitable company called Tree Stories, which really just try to do plant education for folks. And that's how Doug and I connected because we are people who love love tree stories, and we are very enchanted with a particular story about the Washington Monument White Mulberry, which also we know was recorded in this report found by Melanie Choukas-Bradley. She's a local author, and she found it was written by a landscape historian named Jonathan Pliska, who is here with us today talking. So, Jonathan Pliska, welcome.

Jonathan Pliska  05:48
My pleasure. Thank you so much.

Sam Nelson  05:50
Yeah, sweet. So, I'm just gonna… let's get right into it because… I can have you explain yourself… but I'm gonna have you tell us who you are and what you do through the lens of this particular tree. The Washington Monument White Mulberry is to me a tree that's got many, many, many stories - a story of stories. It is an absolute mystery of a tree. It's one of those trees that lists these questions like, “What is it? Why is it here? Is it one? Is it two? How long has it been here?” And when you stand by this tree, you get this a lot - people ask, “What is this tree doing here?” 

It is a mystery, and you, Mr. Pliska, are a landscape historian. But I actually think of you more as a detective because you wrote this really remarkable, cool set of documents about witness trees, including this one. And when I read this particular document - it's like 14 pages long - it reads like a dossier of “who done it?” but it's about a tree. So let's start there. What is a landscape historian, and why were you investigating trees?

Jonathan Pliska  06:53
Excellent question. I personally describe a landscape historian as someone who works to research and document the evolution of a particular place or a particular type of place, i.e. a landscape, over time, and with a specific focus on the ways in which humans have used and modified the natural environment over time. And I really appreciate your compliment about the report, particularly the fact that you found it engaging because I find almost nothing more detestable than boring history, because it does not need to be boring. I feel like, you know, a lot of people who don't end up liking history probably had a bad series of history teachers in middle school and high school and I had some really good ones. So I do try to make things interesting, and I'm glad you like it.

Sam Nelson  07:44
Absolutely, yeah. It reads to me like a story of stories rather than just a dry text. So maybe you can tell us about this particular series of reports you wrote. They're called historical… remind me…okay…

Jonathan Pliska  07:59
Yeah. So they were…it's a series of projects commissioned by an entity within the National Park Service called the Historic American Landscapes Survey, or HALS. And HALS….

Sam Nelson  08:12
I've got like several acronyms running around in my head. So I'm like, wait, HALS? 

Jonathan Pliska  08:18
No problem. I get it. I definitely get it. So HALS is a small part of the National Park Service, but I think a very important one, and it's housed within something called the Heritage Documentation Program. So most people, when they think of the National Park Service, they think about uniformed National Park Service officers out in parks, and that's the vast majority of the Park Service. There's also some folks who do documentation work, and in the summer of 2006, I was 20 years younger, I guess, and I was in my mid 20s, and a graduate student at the University of Maryland, and I needed a summer internship. I've always been interested in history and nature, and probably get that from my background, and trees in particular. And it just so happened that right place, right time, they were doing this documentation project on 24 biologically, but really historically significant trees in the greater Washington D.C. area as a pilot project, which they termed the Witness Tree Protection Program.  

Sam Nelson  09:21
And by the way, that is such a fantastic name for this because  it conjures up so many interesting ideas. When you think of witness tree witness protection programs, you're thinking of a mystery, like something is seen, something bad, they need to be protected. But in this case, we're talking about trees.

Jonathan Pliska  09:37
I couldn't agree more, and the name is entirely from the founding chief of HALS, a gentleman by the name of Paul Dolinski, who is both my mentor and my great friend. He's since retired, but I really owe a lot to Paul.

Sam Nelson  09:50
Very cool. So we have here a series of documents that are about witness trees, and the Washington Monument White Mulberry is a particular, really interesting witness tree. I've read multiple of your reports, and they're all fantastic. But I noticed this one's got a little bit more, like a little more oomph to it. 

Jonathan Pliska  10:09
I appreciate that because this is actually phase two of the project, which came about maybe 6 to 10 years later. It was sort of a rolling project, and it was about another 10 trees in the greater DC area. So it's nice to think that maybe my writing and my research improved a bit since going from a graduate student intern to a budding young professional.

Sam Nelson  10:29
That might be it, and I also think there's an element of this sort of speculative mystery about this tree. So we think about witness trees. These are trees of - and I think listeners of This Old Tree are familiar with  witness trees because so many of them are witness trees. There's different kinds of witness trees, right? There are witness trees which witness very specific or acute events. We have the “Emancipation Oak” down like at Hampton University, which was witness to the reading of the Emancipation Proclamation in the South. There are trees that Frederick Douglass maybe planted at his house, not confirmed, but it's thought he planted some of those trees in the 1870s in Cedar Hill in Washington D.C., and those trees were witness to the end of Frederick Douglass's life for sure.

Jonathan Pliska  11:07
I documented two of those initially. Unfortunately, only one is still there.

Sam Nelson  11:11
So those are trees that are, I would say, more like specific witnesses. But this tree has witnessed a lot, and it's not clear dating how far back? So let's kind of get into this. Let's unravel for our listeners here, let's unravel the mystery together. I'm going to propose a series of questions to you as mysteries, and let's start with mystery number one. How old is this tree?

Jonathan Pliska  11:34
That is an excellent question. My research leads me to believe that it was planted sometime between 1876 and 1886, and so - I went into history and writing, not math. What does that make it? It makes it between…

Sam Nelson  11:54
….140 to 150 years old this year.

Jonathan Pliska  11:58
Fantastic. So that's a pretty good age for a mulberry, right? Because mulberries usually top out right around 100, 150 years. Some are older. I think there's one that ostensibly knew George Washington still growing at Mount Vernon, so it's not impossible. But it is kind of getting up there for this particular species, and the reason I believe it to be from that 1876 to 1886 time period is because of a lot of research and old government reports. 

And as it turns out, during that 10-year period, the federal government was very active in planting trees and bushes on the Washington Monument grounds as part of the initial redevelopment of part of the initial development of the National Mall. In that 10-year period, there were at least 1000 trees planted on just the Washington Monument grounds alone, and the records state that there were two white mulberry trees planted there. And I believe this is one of them.

Sam Nelson  13:04
Well, that must have been a really fine detail you found in a report somewhere.

Jonathan Pliska  13:09
Yeah, my wife can usually tell when I do something, I find something interesting if I'm researching from home because she'll hear me yell, you know, something happy, and you know, do a little dance basically. And I definitely did it when I found that.  

Sam Nelson  13:22
Yeah, I bet. It's interesting because a lot of scientists will use so much biological data or dendrochronology to figure things out. But you are going through incredible historical records. I think we should maybe paint the picture for folks, which is to say, this tree is also unique because when you are approaching it on the Washington Monument, there are no other trees within 100, 200 feet of it. In fact, there are no other trees in that inner circle that surrounds the Washington Monument, that kind of rounded knoll. There are no trees whatsoever. 

It stands out, and I spend a lot of time down there. When you stand by this tree and hang out by this tree, people walk by it all the time, and they'll say - especially, you know, the younger Gen Z teens - “That's random!” Or someone will say “That's a random tree.” Even yesterday, I was looking at it, I was hanging out by the tree taking some notes, and some lady says, "I don't know the history of this tree, but it's sideways. That's crazy!” And then she kept walking. I started running after her to tell her about the history of the tree, but by the time I caught up to her, it would have been a little weird because it's like 100 feet away, and I'm running out of breath in the heat. I'm like, you know what? I'm just gonna….

Jonathan Pliska  14:18
A strange man trying to tell you about a tree, yeah, that, I suppose, could be a… but that would have been my first instinct too.  

Sam Nelson  14:26
Absolutely. It's kind of a phenomenon though, because people are, you know… it's a little bit out of step with the landscape directly around it, and so that is part of the mystery of this tree. And so you're helping uncover this fact that maybe it goes back to 1876 and 1886. 

I think maybe to give people context, you know… you have limited time here, we could do a whole podcast or series of podcasts just about the history of the National Mall. But even right now, as the National Mall is undergoing incredible transformations for America's 250th birthday and the reflecting pool, we won't go into all those details. A lot of things are happening, but it's important to keep in mind the National Mall has changed a lot in its history. Trees have been added, trees been taken away, trees been added and taken away. Buildings have been added, and so forth. So maybe let's talk a little bit about that and how that's tied to the history about how this tree came to be.

Jonathan Pliska  15:15
So, in as close to a nutshell as I can make it, the National Mall is probably familiar to almost all Americans. Actually, probably most people internationally. But it essentially is a large green carpet that stretches from the west side of the United States Capitol building for about two miles to the west down to the east side of the Lincoln Memorial. And on the north and the south sides, the mall is bordered by a double row of American elms, and in the center, like I was saying, is essentially a green carpet until you hit the reflecting pool. 

And the Washington Monument and the Washington Monument grounds are part of that green carpet, except for this one tree that very much sticks out.  I think it's a very convenient meetup spot for tour groups and anybody who might be lost and is trying to, you know, figure out where to go. It's, “Meet me at the tree” because it is literally the only tree, and I think that's been the case for decades. 

So I said a little bit at the beginning about how in 1876, 1886, they were planting…the federal government was planting a bunch of trees on the mall, right? And that really goes back…it started in about 1851 with a plan by a man named Andrew Jackson Downing or AJ Downing, and AJ Downing was the foremost landscape gardener of his time. He was also something of a rock star. People followed him the same way they would like a modern day celebrity. And if you look at his headshot, it kind of gives off rock star vibes.

Sam Nelson  17:03
He has “aura,” as the kids would say.

Jonathan Pliska  17:05
Yeah, I think he was a bit of a heartthrob. I guess I'm dating myself a little bit, though.  

Sam Nelson  17:12
So you're good here. The This Old Tree audience trends upwards, but people catch the young people with the aura of Andrew Jackson Downing.

Jonathan Pliska  17:21
So in this initial development phase of the National Mall, his plan for the mall was really a series of individual gardens that were very much in the Victorian taste. Think dense, dense overplanting, liberal use of light and shadow, winding walks very evocative of the Romantic era, which is really the era that we're talking about. And then by the 1870s, the development that started close to the U.S. Capitol, around the original buildings of the Smithsonian Institution, had sort of crept down to the Washington Monument site, and they began planting there.

Sam Nelson  18:01
Yeah, really interesting. We even go back further than that. I think one of the original ideas was that a lot of folks wanted to be kind of like you said a strolling arboretum, but it was kind of actually wildly overgrown for a long time. And some of the founding fathers and original folks were upset because Washington citizens… and I learned this through I think Jill Jonne's Urban Forests, it's a really great book. She talks a lot about DC's urban history. There were folks, citizens, chopping down a lot of trees for firewood and for other uses. And there was like, it was a gorgeous city that was considered to be kind of wild with forests, and there were people going to the National Mall and just cutting things down. And so it wasn't this ideal romantic place until Andrew Jackson Downing wanted to renovate it.

Jonathan Pliska  18:39
You're absolutely right, and specifically by, let's say the 1840s, things had gotten pretty bad on the mall. The old city canal was running parallel with it, and calling it a canal is pretty generous. It was really more of an open air sewer. It's a great national embarrassment, but there were slave trading companies that operated in the immediate vicinity of the National Mall. It was really kind of a stinky, nasty place, and members of upstanding society at the time didn't really want to spend too much time there. 

So then, instead, the federal government made a concerted effort to essentially turn the National Mall, including the Washington Monument grounds, into a living tree museum. It was very specific wording that said that they wanted to grow each and every type of species of tree, whether they were native to the United States or not, that would grow in the climate of Washington D.C. as sort of like this living bit of interest, a teaching tool. And you know, it's the capital city of the United States, so it was a bit of a prestige thing too. And you live in D.C. You know that it's equal bits north and south. The climate is pretty perfect for growing almost anything. It's right in that sort of “Goldilocks zone.” So there were a lot of different trees that were on this list.

[This Old Tree theme music]

(narrative)
Doug Still  20:08
This white mulberry was not just a weed, as many of them are. It was chosen as part of the National Mall's first major planting plan of the 1850s, and finally planted a few decades later. The plan was created by the father of American landscape architecture, Andrew Jackson Downing. I knew this tree was special. 
We're going to take a short break. When we come back, Jon Pliska explains that beyond the Andrew Jackson Downing connection, this white mulberry has something particularly rare about it that no one has considered for 140 years.

You're listening to This Old Tree.

[Piano music - Gottschalk]

Sam Nelson  21:18
So maybe then we can talk about mystery number two. And we come back a little bit more to the history of the National Mall because I think it's going to be important for how this tree appears. You said they wanted to plant a variety of interesting and unique trees, and here we have a white mulberry, which in some sense we might not consider to be that interesting now, but might be interesting back then. But there's another aspect of this mystery, which is in your report, you say this is not any typical white mulberry or Morus alba, which comes from Eurasia. There's a whole history behind that tree as well. That might have been considered a specific, unique tree back then, but more so, you suggest that this actually might be a special kind of white mulberry, the “Downing mulberry.” 

So, mystery number two: What is this? When people look at this tree, it doesn't have that... like when you see a maple, people kind of know what a maple is, or you see a ginkgo. Even like a lot of average folks, you know, even if they're not tree curious, they know what a ginkgo tree is. But when they walk by this tree, it's like it's a tree. But this actually might be a particularly unique tree.

Jonathan Pliska  22:18
So your basic standard species level white mulberry is Morus alba in the Latin verbiage, and that's what you know most people commonly think of, and for good reason. Sort of beginning in the late 18th century, going into the early 19th century, so right around pre pre American Revolution, all the way through about the 1830s, there was a real push by the United States to begin importing mulberry trees from China to support what was ideally going to be the silkworm industry in the United States, because silkworms famously only eat white mulberry leaves as their food source.

Sam Nelson  23:01
I've heard this called “mulberry mania” in America, which is kind of funny. It's a weird chapter of American history that I was not familiar with.

Jonathan Pliska  23:10
Absolutely, I think it's been covered already on This Old Tree. Briefly speaking, though, it sort of peaked in the 1830s and became a bit of a speculative bubble. I believe the first speculative bubble that's generally recognized in history was actually the tulip mania in Holland in the 1600s, and this is sort of following in on that. And there, I've read some reports where mulberry saplings that were previously trading for three to $5 per 100 went all the way up to $500 to $1,000 per 100. So if you can, you can just imagine the amount of money being pumped into this industry, and how it kind of became its own thing. 

People essentially at some point almost stopped just worrying about this actual silk production. They were just treating mulberry saplings as currency. So this became a big deal until the bottom fell out, just like most bubbles do, in the late 1830s. But I bring that up specifically because the variety of Morus alba that was most prominent during that time and coming over from China was a subspecies basically called Morus multicaulis. I think I'm pronouncing that right. It's often times called either Chinese mulberry or Chinese white mulberry. 

And why do I say all this? Well, because a Downing mulberry is a specific cultivar of the Chinese mulberry, which is itself a specific variety of the white mulberry. So this you start getting nesting dolls, I guess, as far as this goes, and you start getting more and more specific, and all of the Downing mulberries could trace their history all back to the Downing family nursery in Newburg, New York, in 1846 with one single tree. And that Downing name sounds familiar because we were just talking about A.J. Downing on the Mall, right?

Sam Nelson  25:02
I would assume when I heard about this that it was an Andrew Jackson Downing tree that he made.

Jonathan Pliska  25:07
Absolutely, but remember when I said he was a bit of a rock star the first time? Well, he also had a bit of a rock star death because a year after he made the plan for the National Mall, he was coming back to DC to actually deliver subsequent follow-up plans, specifically we believe relating to the White House grounds, when he died in a steamboat explosion. So he passed away in 1852, but his brother, who was an extremely talented horticulturalist and specifically a pomologist, took over the nursery and ran it, and he is the one. His name was Charles Downing. He's the one who came up with the Downing Mulberry, sometimes referred to as the Downing Everbearing Mulberry.

Sam Nelson  25:53
Okay, and he also died kind of tragically, maybe less of a rock star death, but heard he was hit by a carriage.

Jonathan Pliska  25:59
Yeah, and then kind of lingered for about two years and didn't. That was, I believe, the late 1870s. So he at least lived to be… I think he lived into his 70s or 80s. So at least he had a little bit more of a robust lifespan.

Sam Nelson  26:16
Okay, not a lesser of the Downings, but a lesser known of the Downing brothers. 

Jonathan Pliska  26:20
I would say so. Yeah, like he was every bit his brother's equal. He also went on and continued to his brother's books that he had published, specifically the ones on horticulture. Charles Downing updated them throughout his lifetime.

Sam Nelson  26:35
So, for listeners, we should maybe just briefly say what pomology is essentially the study of fruit trees and fruits. So all fruiting trees and thinking it's kind of an agricultural study. All the orange juice we drink today is thanks to pomologists, mostly in Florida and other places. And so these are, you know… Charles Downing was one of the more famous or well reputed pomologists of his time, and he wrote a whole book about fruit trees in North America. 

And I was looking through that book - I saw you reference that in your report - and he was a fan of mulberry trees. Obviously, I saw he wrote that every garden of considerable size ought to contain one or two mulberry trees. He says you don't even have to pick it; it falls in the ground. He recommended you keep the turf short which, lucky for us, the National Mall’s turf is short. But he actually wasn't a fan of the white mulberry itself. He wrote of the berry, it produces fruit of no value. But then he created this Downing mulberry, which, as you said, is like cultivar of a cultivar, and he was a big fan of this particular fruit. He thought it was really delicious. But I guess my question for you, kind of trying to unravel this mystery a little further, is how did you find out or come to speculate that this was a Downing Mulberry?

Jonathan Pliska  27:43
Thankfully, this is a very quick, simple answer. The government report from 1886 specifically called it a Morus downingii... I'm going to I'm going to butcher the Latin name, [sic] a Morris Downwinji, D O W N I N G I I, and I did a Google search on that, and it came up that it was a cultivar of the Chinese white mulberry, and then that went back to white mulberry.

Sam Nelson  28:10
I love that. I feel like we need to go and correct the record and get that out there. That this is a Downing mulberry. All the records say it's white mulberry, which is technically true, but it's a cultivar of a cultivar. Although the issue is - as Doug and I talked about - there's no way outside of that record we found, there is virtually no way to confirm this because there aren't any confirmed examples of it today. So we were talking with some folks about how to test this tree and get some genetic material and sample it, but there's nothing to cross examine it with.

Jonathan Pliska  28:39
Yeah, I mean that's a really good point. The Downing Mulberry was very popular in the nursery trade, as far as I can tell, pretty much right from 1846 when it first showed up in Downing's nursery. For almost a century, the last record I could find in horticultural manuals and advertisements, that kind of thing, dated to 1942. So we're already into World War II at that point, and then it just for whatever reason disappeared. And because it's been out of the public mind and out of the trade for so long, it's not still being developed by nursery growers. So there's no control sample. So you pretty much would need to know by some sort of other reason that this is a Downing mulberry to begin with, in order to compare it to anything else, or to compare anything to it.

Sam Nelson  29:31
Which means potentially there might be more Downing mulberries out there, but we really don't know. This could be the oldest Downing mulberry that exists today.

Jonathan Pliska  29:38
It's entirely possible. I have absolutely no doubt that there are others because you know this tree is 150 years old. It's not unheard of that there would be others, just planted in yards and parks all over the country. And then of course they can naturally propagate, self seed, and pass on their lineage that way.

Sam Nelson  29:59
I have a test. It's a very subjective test. I was thinking about it yesterday. This is my test for how that's a Downing Mulberry versus a white mulberry. So I was looking through that pomology book, Charles Downing, and you know he says the white mulberry has got no value. He's a big fan of the English mulberry, the black mulberry. It's like, that's the most superior berry. But he did say his Downing Everbearing Mulberry. It's a very tasty berry. It's very sweet, second only to the English mulberry, and people don't really eat white mulberries because they're not that great. So my test is this. You see where I'm going with this? 

Jonathan Pliska  30:33
I see where you're going with this.  

Sam Nelson  30:35
This is me using historical data, and I'm going to do a taste test. I'm going to find a white mulberry. They do exist. I'm going to take it down to the mall. That tree is fruiting right now. It's not ripe yet. Although I did notice the starlings… birds are enjoying it. 

Jonathan Pliska  30:49
I was going to say you might have some stiff competition from the local wildlife.

Sam Nelson  30:53
This is, yeah, because it's the only food source for like for an acre. So the starlings are going crazy for it. So this is all. This is a shot in the dark. I'm gonna take my mulberries. I'm gonna go down there, and I'm gonna wait for the ripe mulberries, and I'm gonna eat them side by side. And if it's tasty, - tastier than white mulberry - I'm gonna declare it. I'm gonna confirm your speculation.

Jonathan Pliska  31:16
There's a lot riding on your taste buds. So if you feel like you're up to the challenge, I say go for it. I'm intrigued by this.

Sam Nelson  31:24
My taste buds are not very refined. I eat mostly pizza, but this is super interesting. Most likely these are Downing mulberries based on the report. It's possible that other mulberries were planted, but we also have photographic evidence, and maybe we can come back to our mystery about how old these trees are and what they're doing there. 

Because in 1900 there was the Macmillan Plan which completely changed the National Mall. But there were disruptions, there was World War I, there were funding issues, etc etc -  that's another podcast for some other people. But essentially, what happened was in 1930 everything was raised. Is that correct?  

Jonathan Pliska  32:01
Yeah, I would say that by the late 1930s, that it really started before then. It started with the Macmillan Plan, which is, just to put it very briefly, the redevelopment plan for the monumental core of Washington D.C. And a big part of that was the creation of the Mall, more or less as we know it today. Again, it's that large open space, almost like a green stage, and then flanked by the two double rows of American elms. And the history of the American elm on the National Mall is also replete with history in and of itself. There's a witness tree specifically relating to that and Dutch elm disease resistance. But for the, as you said, for the purposes of what we're talking about here, the…

Sam Nelson  32:53
Which, this tree, just to say… we talk about witness trees. This tree witnessed this transformation.

Jonathan Pliska  32:58
Yeah.

Sam Nelson  32:59
In a pretty dramatic way.

Jonathan Pliska  33:02
There was a...if you can think of… it's really a night and day difference. If you can think of just an intentionally forested, almost intentionally overgrown landscape, moving to what we have now, which is largely open and with green grass, the difference is extreme. And there were… you can see the photographs dating to even to about the 1910s on the Washington Monument grounds, that there are plenty of other trees within that inner circle of the Washington Monument. And we believe that this mulberry was one of them. 

And over the next two decades or so, really by about the end of the 1930s, those were removed in conjunction with the redevelopment of the rest of the National Mall. And we more or less have what we have today by the onset of World War II, and then specifically by about the 1950s, because during World War II, the Washington Monument grounds housed a lot of temporary war structures. Anything from barracks to storehouses to you name it. They were very inexpensively built, and it's pretty amazing if you see a picture from that time. You can, other than the fact that there's the Washington Monument sort of sticking out of this cluster of buildings, you wouldn't recognize it. So something clearly happened to this mulberry during that time, and that deepens the mystery to continue with your line of thought.

Sam Nelson  34:40
Just, just say it. We killed it.

Jonathan Pliska  34:44
Yeah. So the way I believe…

Sam Nelson  34:48
We probably killed it.

Jonathan Pliska  34:51
I believe the way things went down was that the federal government, as part of the redevelopment plan, intentionally cut the tree down to the ground. Both of the Downing mulberries, sometime in the neighborhood of 70, 75 to 80 years after it was first planted.

Sam Nelson  35:09
It wouldn't have been considered a remarkable tree at that moment. It's a Downing mulberry that exists. It's, you know, it's 50 years old. 

Jonathan Pliska  35:16
Yeah, and the only notation that it was a Downing mulberry to begin with would have been in this very esoteric government report that….

Sam Nelson  35:25
So it's probably just, this tree is dropping berries on this monument that we built, and they're just… it's time to go.

Jonathan Pliska  35:31
Yeah, and you know, that's one of the reasons why I think it's relatively rare. White mulberry in general is relatively rarely planted in a sort of an urban setting because it can become a little bit of a nuisance tree because of its fruit production. Also, it's pollen. I am famously allergic to mulberry trees. So, yeah.

Sam Nelson  35:51
This tree is like your “frenemy.”.

Jonathan Pliska  35:54
I did not visit it while it was blooming, so thankfully, yeah.

Sam Nelson  35:58
So this is the twist of the mystery, right? So the National Mall, they planted these elms, they cut down a bunch of these trees, and yet here we are looking at it today.

Jonathan Pliska  36:10
Yeah, and that was really the last bit of the mystery that sort of stuck out at me as I was doing this research. I kept being like, “Okay, all right, this domino falls, that domino falls.” I'm putting together, I believe, a really high quality narrative about where this tree began and what it's done throughout its lifetime. But it was like, “Yeah, okay.” So why would this one tree and only this one tree have been spared the saw, so to speak, and somehow survive World War II on the Washington Monument grounds?

Sam Nelson  36:43
The mulberry tree next to the Washington Monument. Of all the trees to survive, it's unlikely.

Jonathan Pliska  36:48
Yeah, and “Occam's Razor” very much says, "Well, they probably didn't.” So I was like, "Okay, so what would be the other possible solution?” And I'm racking my brain about this, doing every research I possibly can. And I don't even know how, but I know it was about three a.m. I couldn't sleep because, in large part, this was rattling around in my brain. And I found a short five page scientific journal article from 1987 from researchers out of the University of Kyoto in Japan. It literally was just titled something along the lines of "Branching and Resprouting Habits of Morus alba.” 

I'm like, well, that sounds like that would be useful to read, and I did. It basically just said, complete with scientific drawings, that under normal circumstances a white mulberry will grow like a standard tree with a single stem for the most part, and if it's cut back down to the ground, there's a high chance, 1) that it's going to resprout, and 2) if it resprouts, it is going to come up with multiple leaders, or in this case, secondary stems, kind of secondary trunks that come out in a fan shape and come out in all angles. 

And well, that is exactly what this tree looked like back in 2016, when I wrapped up this report. There were five sort of secondary trunks that were present above ground. Four of which, more or less, came up out of the ground vertically, but kind of in a fan-shaped arrangement. One was probably dead already by 2016, but three were alive. And then there was one other, almost at this point the major trunk that was coming out at this really odd, acute angle, a few feet away, and just sort of going for it. 

Sam Nelson  38:56
This is one of the first things that people notice about this tree. It's like, “Oh, it's a tree, and why's it leaning almost like a staircase?” Or an escalator.

Jonathan Pliska  39:06
And I went, “Well okay, well that absolutely makes sense then, because that explains why it looks so strange too.” So it was cut down probably in the 1930s, allowed to resprout, and it grew into this form that we have today.

Sam Nelson  39:28
It's a comeback story.

Jonathan Pliska  39:30
And it's a relatively fast growing tree. And there's a… I don't know if you had a chance to see it, but the Library of Congress has a winter scene, and it's got the tree sort of with the Washington Monument silhouetted behind it. And it says it's from the '40s. So I have some doubts about that because there's no war buildings on the Washington Monument grounds, so it might be slightly misdated. But if you want to think of it, maybe from the '50s.

Sam Nelson  40:00
Okay.

Jonathan Pliska  40:00
It's got much much smaller secondary, at this point, I guess you could call them primary trunks than it does today, or it had 10 years ago. So it really jibes with the idea that this regrew.

Sam Nelson  40:16
So this brings us to mystery number three. Or mystery - I don't know what number mystery we’re on, but this was all really interesting. Charles Downing also mentioned that these trees, when you cut the roots, they will resprout. So this is all this part - when I read that report that was kind of a shocker for me. I hadn't thought about this because in all the reports, when people look at it, and say, "Look, those are two trees,” so this is our mystery now: is this one tree, or is this two trees?

Jonathan Pliska  40:47
I guess it kind of all depends on what your definition of a tree is, and I know that might sound sort of silly or semantic, but…

Sam Nelson  40:55
It’s not silly or semantic at all. It is actually… I do tree tours in Washington D.C. It's part of my business, to share knowledge, and I start every tree tour the same way, which is I ask people, “what is a tree?”

Jonathan Pliska  41:07
So, I guess if I can just turn it around on you and ask you a question, then. If two stems are coming up separately, for instance, but they're part of the same root system, are those two trees or one to you?

Sam Nelson  41:21
I love this question, and Doug might never invite us back after we bog this whole podcast down with what is a tree. It's a great question, and so I think about aspens out west, for example. They grow by seed, but they mostly grow rhizomatically, right? So they grow through these root systems, and they send out ramets, and all those trees are genetically the same. So some people call them colonies or clonal systems, and so it becomes a question: Is that one tree or is it many trees? 

I like to live in the gray area. You know, I don't want to say is it one tree or is it many trees. I know this feels like I'm dodging the question a little bit, but it gets into… and this is where I'm just kind of a geek. It gets into these greater philosophical questions about where does the tree begin and where does the tree end? Where does an organism begin? Where does an organism end? I won't go down that rabbit hole because we're focusing here on the Washington Mulberry. I like the idea of calling it one tree because it shares the same root system and it's not spread out over a long period. When you look at it, there is a central, I won't call it nub, but there is a central place where these roots are sprouting from.

Jonathan Pliska  42:29
I'm on board with your definition here, and what's interesting to me is, and this is sort of making lemonade out of lemons. In 2019 - so just a couple of years after I finished up my work - there were not one but two major windstorms in Washington D.C. And this Downing Mulberry on the National Mall, right by the Washington Monument, was uprooted not once but twice in the month of May. And basically the NPS, who's in charge of the tree, and is doing an amazing job by the way, was able to determine, I believe, pretty clearly that it was all part of one root ball. Because all of the stems came up, and that also explains why today there's really only two stems left. There's one that's more or less vertical. I mean, you were just there yesterday. Would you say that that's at least relative to the rest of the tree?

Sam Nelson  43:33
We'll call it “vertical-ish.”

Jonathan Pliska  43:34
Okay, and then there's…

Sam Nelson  43:36
It's definitely not as vertical as it once was. It's not as much as the Washington Monument.

Jonathan Pliska  43:41
Exactly, but relative to what I call the long leaner, it's pretty vertical, and that's essentially right what we have left of the tree today. And now it's because of the efforts of the National Park Service, which really did move heaven and earth to save this tree. And if you think about it, that's poetic. That's full circle. The federal government, according to my research, plants it. Then they cut it down, let it resprout and regrow, and now are moving heaven and earth to save it.

Sam Nelson  44:10
It would have been a perfect excuse to remove this tree that is not in keeping with the landscape anymore. They could have been like, "All right, it's time to go, but they re-propped it. Then I was looking at the photo, the photos from 2019, the video, and they recovered what looks like the root ball, but actually, what they did is they added earth back on top of the root system.

Jonathan Pliska  44:28
Yeah, I mean that's a pretty extreme measure to try to keep it alive and healthy. 

Sam Nelson  44:34
It did, and the leaner looks great. It's actually healthier than the vertical one. It's leafing out full foliage. It's got new growth on it. I was kind of taken aback by it yesterday.

Jonathan Pliska  44:42
Yeah, and so that was seven years ago at this point, and it's got a little fence around it, I believe. So people hopefully don't climb on it anymore, and it's got a system of supports. And you know, going back to the way you introduced this was the lady being like “that's a weird-looking tree.” She's not wrong. It's about as horizontal as a tree can be and still be in the ground.

Sam Nelson  45:09
When I moved to DC around 2015, there was no fence around it back then. And every time you go down the monument, it's inevitable. Children have to… they don't even have to climb it, they just walk up it like a staircase. I don't blame them. Since that storm they fenced it off, and it's a tree you probably shouldn't walk on because it's been around for 150 years.

Jonathan Pliska  45:31
It's one of those trees where you can't help but notice it, and that is, I think, really good because it's been on people's radar for I would say probably 150 years.

[This Old Tree theme music]

(narrative)
Doug Still  45:46
And flipping the perspective, it's hard to imagine any other tree in the world better placed to witness history. After this short break, Sam and John talk about what it means to be a witness tree, and what events the Washington Monument Mulberry has presided over. This is This Old Tree.

[Piano music - Gottschalk]

Sam Nelson  46:44
So, as you mentioned, it's a tree that gets noticed. I hope in this podcast - the wonder of this whole tree - we're asking people to pay even more attention to it. A little bit of attention to pay more attention to it. But this tree, it also sees us in a way. We won't go into plant science of what trees influence or what trees can see or perceive. That's its own interesting rabbit hole. But this is a…we talked about earlier. This is a witness tree of significance because it is in prime historical real estate. What has this tree witnessed?

Jonathan Pliska  47:23
Well, I'm going to start with something that is going to be probably a little out of left field. I have a three year old daughter, and just like any father, I've seen the movie “Frozen” approximately 10,000 times already. And there's a line in that movie that sticks with me, and it's that water has meaning, and water has memory. And so do trees. 

I've been thinking about that a lot lately, meaning and memory. That's really the crux of, not just this tree, but any witness tree. As far as this tree goes, think about what it's seen. It's not only seen the redevelopment of the National Mall and the Washington Monument grounds used as a temporary barracks and storehouse during World War II. It's seen Dr. Martin Luther King Jr’s. famous "I Have a Dream" speech, and all of the anti-Vietnam War protests, and honestly every major… anytime anybody wants to go to the mall for anything to protest or to celebrate - this tree's been there for a long time.

Sam Nelson  48:28
Trees don't have eyes exactly, but in some ways it's got a view of the Capitol and it's been witness to every single inauguration of presidents since the 1870s, which is also crazy to think about.

Jonathan Pliska  48:40
And Woodrow Wilson signed the Enabling Act, the Organic Act that founded the National Park Service in 1916. And the White House has a pretty good view of the Washington Monument and this tree as well. So, you know, it was there when the National Park Service, its governing entity, came into existence.

Sam Nelson  49:01
My gosh, I didn't even think about that angle. It is almost directly in the sight line between…we're actually blocking the sight line between the Jefferson Memorial and the White House. So it's got the full, full range of…

Jonathan Pliska  49:14
Absolutely. That was part of the intention of the Macmillan Commission and the redesign of the mall.

Sam Nelson  49:19
Fascinating.

Jonathan Pliska  49:20
Just like there's certain witness trees that, okay, what does it tell you? Well, the tree that listened to - we talk about what trees have seen - but that that listened to Abraham Lincoln deliver the Gettysburg Address. Well, that's a pretty specific moment in time. This tree is a little bit different in as much as it's open ended, and its historical significance is ongoing. Every time, even if there's a family trip to Washington D.C. and you go on a school trip and you go to see the Washington Monument, you're adding to that history. So this is unique and special in that regard. 

The thing that really sticks with me is the… I guess the quintessential American value that's sort of embodied in the tree is, just don't quit. If you believe in something, survive, fight, give it everything you have. Yeah, this tree is absolutely a survivor, and I think that that's something that really resonates with, I would assume just about everybody. It certainly does with me.

Sam Nelson  50:25
I love that. I love that because you know it's seen a lot. It's seen the good, the bad, the ugly. It's American history. It's a mixed bag in a lot of ways, and each tree has its own particular story of survival. That was beautiful. I appreciate that. Well, there's a lot… I mean, I don't want to get philosophical and get into all the stuff about tree memory. That might be something to do over a beer sometime.

Jonathan Pliska  50:49
Oh, that sounds good.

Sam Nelson  50:50
Yeah, that's interesting. Trees do have genetic memory, and this is why I'm interested in trees and tree stories, and why I try to educate the public. And I work a lot with kids, and we talk about it, the timescale of trees. They have an incredible timescale, and you think about not just the timescale of one tree, but genetically going back. A lot of research shows that they're carrying this history, this memory. Maybe not in acute social events, but there's influence happening between organisms, and they carry that with them in their DNA in really interesting ways. And so it's kind of hard. Sometimes it's very anthropocentric to think about memory in a tree, but like you said, this tree - it's been here, it's been with us. It's not only witness to American history, but now it's kind of American history itself. I don't know. 

I think about the contrast of architecture and style because there's a particular vantage point. So anybody listening to this, I highly recommend to go down to the mall. If you stand next to it, you actually can see the Washington Monument almost like jutting out in between these two stems. And there's this contrast of architecture and style. The Washington Monument is man-made. The foundation was laid by enslaved laborers, bluestone. It's been through emancipation, and now it stands tall and straight and sturdy. It's pointing up towards the heavens, and then next to it is the mulberry, and it's almost - I mean, you think about the completion of Washington. It's almost just as old, and it is leaning towards a fall. It is propped up. It's hollowed out in places. It is a huge contrast in styles, and like you said, it's a survivor. Sadly, the Washington Monument will probably go on for as long as Washington D.C. goes on. The mulberry will probably not. You know, it very well might fall in our lifetimes.

Jonathan Pliska  52:37
That's true. If I may, the good news with that is that there's always the possibility of genetic lineage that may or may not be happening with this tree. I don't know. I know the National Park Service has done that with some other historically significant trees in the past. For instance, the historic so-called “Jackson Magnolia” on the south grounds of the White House, that according to lore, dated all the way back to Andrew Jackson's time in the mansion in the late 1820s and 1830s, finally needed to be cut down for safety concerns. This was a year ago, this past April, in April of 2025, after being on the grounds for the better part of 200 years. If you believe the stories, and whether you do or you don't, it was pretty much the old, one of the oldest, if not the oldest, trees on the White House grounds, and it had this huge significance to it, and it's been replaced by a direct genetic descendant, a clone, basically of the same tree in more or less the same spot, like within a couple feet. 

So that also speaks to memory and meaning. And even if the tree is, in this case the mulberry, is not replaced, I've just… this might be interesting to Doug, considering he's in Rhode Island. HALS and the National Park Service has had a longstanding relationship with the Rhode Island School of Design - I think it goes back to 2009, if I'm not mistaken - where the Park Service has been sending the School of Design wood from deceased witness trees from Park Service properties to be used in design projects. It's really fascinating. I encourage you to go on the school's website, and sometimes it even involves a field trip to the National Park Service site where the wood came from. And that's a fantastic way to continue the lineage and the history of the tree, even when the tree is already deceased. It continues to give it meaning and value in the current day.

Sam Nelson  54:53
I guess I don't have to ask you to imagine it, but if it falls, how will you feel? You spent a lot of time researching this tree and thinking about it.

Jonathan Pliska  55:01
Yeah, I guess it'll feel like losing a friend. To be perfectly honest with you, it'll be sad. But it's also whenever you lose someone close to you, hopefully they've lived a long, happy and productive life. And I don't know about happy, because as much as we'd like them to, trees don't always talk back to us, at least not verbally. But it's certainly been productive and meaningful, and that'll give me solace as well.

Sam Nelson  55:32
I love that. That's a great way to think about it. I like this. I appreciate you giving respect to this tree and giving power to this tree and calling it a friend.

Jonathan Pliska  55:41
And the National Park Service is doing an absolutely fantastic job. They are doing everything they possibly can for it, and they should be very much applauded for that.

Sam Nelson  55:51
Absolutely, we just need… maybe we can get a sign. But they're doing a fantastic job. They're doing 1000 things. This may be lower on the radar, but I'd love to get a sign there because so many people do pass it, and like that's a random tree, and there absolutely must be something up with that tree.

Jonathan Pliska  56:07
Well, hopefully the Witness Tree Protection Program documentation has helped get the word out there. There's also things about the tree online now through the National Park Service and other entities. So if anybody's interested, I would absolutely encourage them to go to the HALS website or the website of the American Society of Landscape Architects, which is HAL's founding system. ASLA was involved in the founding of HALS and continues to have a strong working relationship, and they also have guidance on their website. In fact, ASLA is launching a challenge for HALs. This is going on right now, called Landscapes of Liberty, and it ties right into the theme of America 250.

Sam Nelson  56:53
That'd be super cool if we got some submissions from folks listening. If they got some submissions for this, because historical landscapes don't have to be in Washington. They could be from all over. 

Jonathan Pliska  57:02
They don’t even have to be federally owned. There are other witness trees in the greater Washington D.C. area. So, if anybody's interested, I can provide Doug with my email address, and you can get in touch with me.

Sam Nelson  57:18
Well, I guess maybe I'll add one more thing, which is I just want to say how much I appreciate your work on this. You know, one of my inspirations, Robin Wall Kimmerer, is a Potawatomi citizen and the author of Braiding Sweetgrass. She's an indigenous scientist and writer, and she talks a lot about how paying attention to plants is really a big and important thing in how we reorient our stories and our narratives. 

When we talk about big witness trees, if we go out west, you see the sequoias and the redwoods, and there's this moment of awe. You feel like you're in the presence of something majestic. When you approach this particular white mulberry, you don't necessarily get that feeling of awe, but you've actually changed the narrative for me a little bit because you have put so much time and attention into this, which in itself is showing a lot of respect for this living organism. It has given me a more nuanced sense of awe. So knowing the context in history of this particular tree, in this place, and now when I approach it, I get a different kind of feeling because of the work that you've done. I hope this spreads out to other folks. I hope when folks come up to this tree, they feel that. And also, as you mentioned, in this invitation for other folks to dive into the history of historical landscapes, and maybe elicit some awe through that sort of attention.

Jonathan Pliska  58:34
Yeah, absolutely. It's easy to just sort of zone out when you see trees, they're pretty ubiquitous. But you're right. There's something about, say, the General Sherman out west or what have you, that's just absolutely awe-inspiring. And then, well, I don't want to keep going back to the lady that you ran into yesterday. But you know, people that just go out of their way to say that's a weird tree, they're noticing, and that's really the first step to caring and to being curious. You have to notice it in the first place. So, in as much as this tree gets anybody to pay more attention to their environment and to trees, I think that's an absolutely wonderful thing.

Sam Nelson  59:22
So I just want to say thank you, John, for your time today. Thank you for your attention to this particular tree and for attention to the trees of Washington D.C. and across the country. And thanks for hanging out with me today. This was super super enjoyable to hang out and talk about this tree and history, and much appreciated.

Jonathan Pliska  59:40
It's absolutely my pleasure. Thank you so much.

[This Old Tree theme music]

Doug Still  59:43
Well, I can breathe a sigh of relief now that I now know the real story behind the Washington Monument mulberry tree that I've seen so many times. So cool that it is tied to Andrew Jackson Downing's original plan for the site, and also his brother Charles Downing's historic nursery. It's truly an impressive provenance. And to boot, this tree seems to be the only known specimen of the Downing Mulberry. I sincerely hope that Jonathan Pliska's research spurs further study and, better yet, propagation of this tree so embedded in American history. 

[Piano music - Gottschalk]

Sam, you were a great tree correspondent! I want to thank you and Jonathan Pliska for your thoughtful and fascinating conversation. I really felt like I was in the room with you. Listeners, you can find out more about Sam Nelson's work and tree tours on his website samnelson.xyz. I'll put it in the show notes. You can dive into some of John's research with the Historic American Landscape Survey, or HALS, on the National Park Service website. I'll include that link as well. 

The music you've been listening to is a piece by Louis Moreau Gottschalk called "The Dying Poet.” It was played just for us by my good friend and pianist Jim Rice. Gottschalk famously performed in Washington in 1864 as part of his Civil War time concert tour. President Lincoln and the First Lady were in attendance. The show's theme music is by Dee Lee. Visit the show website at ThisOldTree.show. A transcript will become available soon. Follow us on Facebook and Instagram to see photos of the Washington Monument Mulberry and our guests. The podcast is a sponsored project of the New England Chapter of the International Society of Arboriculture. Visit NewEnglandISA.org to learn more about this great organization. 

Happy 250th birthday, America! I'm Doug Still, and this is This Old Tree.

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