Episode 03: Witches Brooms and Reference Garden

In this podcast we discuss a unique aspect of conifers known as a Witches Broom. These unique growths are often due to different stresses that can occur with these plants and often lead to novel growth patterns, colors, and arrangements. David Horst tells about how these have been incorporated into the collections at the arboretum, and how many of the witches’ brooms that are there are local growths that he himself has discovered and, in some cases, even had the opportunity to name. He also tells us how the arboretum became a reference garden by the American Conifer society and why that is important for the educational goals of the arboretum.


Ryan Welch: 
Welcome to another podcast about the people and plants of the Bickelhaupt Arboretum in Clinton, Iowa. In this podcast, we go a little deeper into the subject of dwarf conifers, more specifically discussing the occurrence of a rarity of what are known as Witches Brooms. 

As we learn, these are rare genetic growths that can occur for a number of reasons on an already mature plant. According to the American Conifer Society, most trees will have a leading chute, and that leading chute will produce a plant hormone known as auxin. 

This auxin slows the growth of secondary and tertiary shoots that come off of it. This also helps to limit overgrowing by these parts of the plant, which could be a detriment to the tree itself if there is an interference in this mechanism. 

It could happen for a variety of reasons in nature due to solar, radiation, viruses, disease or even fungus. In fact, some specific species of fungus actually create witches broom in specific tree species. If the witches broom occurs due to a genuine genetic mutation at the growing tip, it will often result in plant material that can be regrown or propagated into a new type of conifer that may be of horticultural value. This is the hope for many folks that actively search out and hunt for these witch's brooms in a variety of locations. Their hope is to discover that next interesting dwarf conifer that they themselves and others can enjoy in conifers 

Witches brooms most often occur in the pinaceae family. More specifically in the genre abies which is the fur, picea, which is a spruce and pinus which is the pine. Just because though they are common in these groups of conifers doesn't necessarily mean that you can't discover them in other types of conifers. 

Often these genetic mutations can result in color variations or distorted variations of the leaves and stems, but often they are also slow growing or dwarf clusters of shoots. As we will learn, the hunting of witches brooms can be an exciting hobby for some, it is a hobby that does require, though, a lot of time and patience since the plant material grows so slowly. And it may take years for a witch's broom hunter to know if the plant material that they found and propagated will result in the dwarf conifer that they were hoping it would. 

If it does, the person who made the discovery gets the distinct honor of naming this new one of a kind conifer for all the world to know. The addition of various witch's brooms to the arboretum, some of which were initially discovered on the grounds themselves, along with the rest of the extensive collection of dwarf conifers that is in the Heartland Collection has given the arboretum the distinct honor of being recognized as a reference garden by the American Conifer Society. This makes the arboretum one of only three reference gardens in the state of Iowa. The Arboretum has also had the honor of showcasing this particular collection, as well as the other collections during a variety of conifer conferences on all levels nationally, regionally, as well as statewide. I hope you enjoy learning about these rare genetic distinctions in the Conifer Group. As much as I enjoyed talking about them with David Horst, the director of horticulture for the Bickelhaupt Arboretum. 

David Horst: He wanted to have those that were already named and proven throughout the United States, but he also wanted to raise some that they call witches brooms. 

Ryan Welch: Okay. 

David Horst: These are kind of experimental plants or mutations that form on a tree and you collect it, propagate it. He wanted to have these and he wanted to have them labeled properly, too. So people knew they weren't able to be purchased at a nursery. 

David Horst: They were just kind of in the study stages at this point. 

Ryan Welch: So why is it called a witch's broom? 

David Horst: Well, most of us think of a witch's broom as a broom used by a witch in a fairy tale. According to the American Conifer Society and in a horticultural sense, it's more familiar as a disease or mutated mass of dense, deformed twigs, foliage forming a bird's nest like structure in a tree. 

Ryan Welch:  Okay, so it's brought about most likely, probably from some kind of a stress that that tree has had to deal with, whether that's a stress from a disease such as bacteria or virus or stress because of environmental conditions. 

David Horst: Right. And the ones we want are probably solar radiation induced or environmental, like you said, that are actual become genetic mutations. 

Ryan Welch: Okay. Because a lot of people don't realize that, that trees also get sunburns to a certain extent. That's solar radiation that is coming down and hitting them as well, you know, living things just like us. And so some of those areas, especially if they're new shoots, that solar radiation can cause mutations in the DNA and thus that those DNA mutations can cause odd growth, like we would call it cancer in some ways. But it's sort of like that except in the tree finds a way to contain it to one little spot. And that, when you look at that, it looks very disheveled, a upheeved look at the end of a witch's brew, I'm guessing. Right. Okay. 

David Horst: And they're not real sure what exactly caused them, but that's one of the main theories. 

Ryan Welch: And there's a probably a variety of things that can cause it that's just, you know, this one happens to be or, you know, many of them. A common reason they come about is because of the solar radiation. 

David Horst: Yeah. And the reason they think that is because a lot of them, even here at our altitude, what are we, 550, 60 feet above sea level 

Ryan Welch: Yeah 500 to 600 feet right around in that area. 

David Horst: We're right in that area. We find them here in the Midwest. But on a larger scale, they are found like in the high mountain areas. 

Ryan Welch: Where you're closer to the sun. 

David Horst: Eight, 9000 feet in altitude or higher. You can drive down the road and you can spot them here. And they're much, much more common now. 

Ryan Welch: Are they also more common in areas where like, for instance, if a tree lost some limbs on one side and we had new growth on the other side because it would be exposed more to the sun, you see more common in areas like that even. 

David Horst: Uh, we haven't noticed that. 

Ryan Welch: Just curious. 

David Horst: You know, and we find a lot of them interestingly around the Midwest here in cemeteries. And it has nothing to do with the people buried there. Oh, sure. But it's the larger size of evergreens. We believe a lot of cemeteries have evergreens that have been growing there for many, many years. 

Ryan Welch: You know, people die that they had this nice, beautiful spot to put their relatives and they always want to plant a tree there. Yeah. You know, he's going to play on Evergreen because it's hardy and whatnot. And after a while, you know, because some of those and some of those old pioneer cemeteries, some of those evergreens are probably, you know, a couple hundred years old maybe. 

David Horst: Right. And that increases your chances of having a broom growing in them. 

Ryan Welch: Just like with age and people, it increases your chance of problems with cellular growth as well. 

David Horst: Yeah, and I've been very fortunate to have met Chubb in the first place here, but I've met a lot of other top conifer experts throughout the country through Chubb over the years. Yeah, one of them also is from across the river here. 

Randy Dykstra. Okay. Randy and Chubb, of course, collected witches brooms for many years. And I was fortunate because they took me along with them. We go on, we'd spend a whole day on a weekend driving around, checking cemeteries, driving through towns, looking for evergreen trees, looking for witches brooms. 

So I was very fortunate to get to go with them. And a lot of this happened during the wintertime when they could be propagated. So we had a big poker which 48 feet, we just keep putting the sections together that were like six foot sections and you had to lean it on a limb because after you've got it up about 20 feet, it start getting top heavy. You had to turn her head up the top. And of course, we'd weave it up through the limbs to where the witch's broom is and we'd take a snip off if it was out in the country. Sometimes we would use a firearm. And I had those, so I would take that and then we could shoot a piece off. 

Ryan Welch: Oh, okay. 

David Horst: We never we never wanted to take the whole witches broom because the genetics would be lost forever if we didn't get any to take. 

Ryan Welch: Yeah. 

David Horst: All right, well, all you need on it is a little piece called a Scion. 

Ryan Welch: Ok, what’s a Scion have on it. In terms of the plant anatomy. 

David Horst: It would be. 

Ryan Welch: Like a node. 

David Horst: Yeah, there'd be a node. Usually some buds out in the end. And what you wanted to graft was usually just one or two years of growth. 

Ryan Welch: Okay. There's a lot of people don't realize that plants are what we call totipotent. And what we mean by that is you can take a piece of it just about any piece of the plant. If you ever if you subjected to the right hormones in the right conditions, it'll grow roots and leaves and all that kind of stuff, even from whatever kind of a cutting you have. And you can do that if you know what you're doing. And sounds like that's what you guys were doing with the witches broom you were taking just that right piece and finding a way to get it, put it under the right conditions, to have it grow and give you what you saw in the tree, correct? 

David Horst: That's correct. We didn't really have the proper facilities here at the arboretum. Chubb had a greenhouse and Randy had a greenhouse, and they had some other growing structures, kind of like cold frames. Yeah. So they would take the small pieces back. 

Like I said, we leave the entire room intact and possible because if we didn't get to grow, we'd go back next year and collect it again. 

Ryan Welch: The genetics are still there 

David Horst: Still there, the genetics are still there. But once we cut it off, it was gone. Yeah. So Randy and Chubb did a lot of the propagating. They propagate it for themselves, for their friends, and also for the arboretum. 

So if I'd go with them, we'd find some plants, they would propagate it and they'd give us a plant or two to plant out in the collection. So it worked good. And a lot of these blooms when they're found, like by Randy and Chubb, if it was found here at the arboretum, they would call it Bickelhaupt Arboretum. Made it easy to remember where it came from. Yeah. Chubb kept 

Ryan Welch: In the naming process. He would say, okay, this was out at the Smith Farm. So the Smith Farm which witches Broome, for instance. Right.  

David Horst: A lot of people did it that way. I did it that way with the white spruce I found here in Clinton. I called it Cleveland Road. 

Ryan Welch: Oh, okay, that makes sense. 

David Horst: So, yeah, road name or the owner's name that owns the property, the park, cemetery, lot of them are named after cemeteries, so that works good. So over the years, we have found nine of them growing here at the arboretum. 

Ryan Welch: Wow.  

David Horst: A lot of them didn't get propagated because by the time we'd find them, they were already dead. The problem with witches brooms are remember now there are slower than the parent plant. Okay, so the parent plants growing, say a foot a year. 

The witch's brew might only be grown two inches a year. It doesn't take many years for the parent plant to cover up the witches broom because it can't keep up. So it's not getting sunlight and it gets crowded out when it dies. 

Ryan Welch: That might be a defensive mechanism around the main plant to try because. Right. It's not normal to it. 

David Horst: To it. 

Ryan Welch: It's you know, it's like a mold or something you might have on your arm kind of thing. It's like, Oh, we've got to get rid of that. Yeah, cut these things off. 

David Horst: And two of our most important broom finds here at the arboretum that have become growing throughout the nation, now, collected throughout the nation. One is Green Twist. And again Chubb and I came up with the name Green Twist by the foliage on the plant. 

We found it here at the arboretum. Instead of calling it the arboretum or Bickelhaupt, we called it Green Twist because a cool twist the needle.  

Ryan Welch: Oh, okay.  

David Horst: And it was green colored.  

Ryan Welch: Make sense.  

David Horst:  Green twist. So that's another way they name plants. 

It's also by the foliage or the plant shape maybe. 

Ryan Welch: Too often I get told by students all by the names and are so difficult and that was looks like sounds to me like you guys went simple with it. Yeah, that's always helpful.  

David Horst: So and then the  

Ryan Welch: from a marketing standpoint. 

David Horst: We kept it very simple and that came off of contorted white pine, which is growing right off the back corner of the building here at the arboretum. And another one was on a mugo pine right along the waterfall. 

David Horst: It was a mugo mops. And I was working there one day back in 1995, and I noticed something unusual. I couldn't tell if it was a broom or if had been injured and then shot out a bunch of little growth. 

I waited a year and it came out dwarf again. So then I called Chubb and said that I'd found a broom and I kept saying, It's really choice Chubb. I really like it. And he said, Well, just give me a name. 

What are you going to call it as? I don't know. You can name it whatever you want. I've never been very clever with the names. So the next time I talked to Chubb, he had named it Dave's Choice because. 

Ryan Welch: So it's named after you. 

David Horst: And then I kept saying it was choice. And we also have that plant growing here at the arboretum with Green Twist. So the parent plant has gone, but we have the broom. 

Ryan Welch: Which means technically, genetically, you still have the genes. 

David Horst: We still have the gene, yep. 

Ryan Welch: The genes in some way. 

David Horst: And both of them have been propagated throughout the United States. You can't go to WalMart or Home Depot and buy them, but if you go to a collector, you can find them. And I see they're even over in Europe now, so it's amazing how plants travel. 

Ryan Welch: Yeah, and that's good and bad. 

David Horst: Good and bad as long as they're careful and inspected. 

Ryan Welch: Inspected, yeah. 

David Horst: For diseases. And insects. 

Ryan Welch: In terms of the history of this place, that's one of the reasons that this place was founded, because plants travel as well as all the diseases like Dutch Elm Disease and chestnut blight. 

David Horst: Emerald ash. 

Ryan Welch: Emerald ash borer. And so yeah, we would we would hate to have this choice be a backdrop for something we don't want. But it is really cool to know it. You know, this thing that you found and you got a name and that is, is, you know, originally from this spot right here has been able to go around and other people been able to appreciate it, enjoy it and like it for the same reasons you did.  

David Horst: That's right.  

Ryan Welch: That's very cool. 

David Horst: And it's pretty addictive once you find one. 

Ryan Welch:  Yeah. Once you find one, I can see, where you know, nobody has ever seen one, like, I’m the first one to discover this original thing in my backyard. And now here we go with it. 

David Horst: And the only problem with dwarf conifers is they are a slower plant, which is good. Keep them small scale for your house. But the bad part is if you find the broom and you propagate it, it's going to take years and years to know what that shape of. 

It's going to be the exact color, if it's a worthwhile plant to even keep raising. Sometimes they do weird things, sometimes they just die for unknown reasons. Like maybe they're not all there genetically. Yeah. And then other times they turn out to be wonderful new plants that may become a new plant on the market. 

Ryan Welch: So it sounds like for those people who collect those kind of things and are into the, the witches broom, the dwarf conifer thing, patience is a big thing. 

David Horst: Patience and it's a long term time investment. 

Ryan Welch:  Yeah. It's not something that, you know, you're going to you're going to know exactly all you need to know about it. You know, within a month or a couple of months or even a year, it may take, you know, half a decade 

David Horst: Like a perennial. You can propagate, you can raise it from seed, cross-pollinate it whatever, and come up with a new plant, you know, within a couple of years. What you got?  

Ryan Welch: Yeah.   

David Horst: But with a conifer, you're looking at 15, 20 years, probably minimum, especially a dwarf. 

Ryan Welch: Now those dwarf conifers, do they put out cones and whatnot? 

David Horst: Yes. And that's another aspect with finding a witch's broom. Hopefully you can find one that's got cones and just like the broom being smaller than the parent tree. Usually the cones are also smaller than normal growing cones, 

Ryan Welch: Are the seeds in the cone viable? 

David Horst: Sometimes are viable and sometimes they are not. 

Ryan Welch: It's one of those. It's one of those experiments.  

David Horst: Yeah.  

Ryan Welch: You know, you go with it, you plant and you see what you can do. And if it comes up, woo-hoo if not. 

David Horst:  You, you know. That's right. And there are people that just collect the seeds and propagate those. Randy and Chub used to do that, too. They'd grow flats of them, especially Randy. I remember going over there and Randy always said, This is just a rough estimate on Randy's part, but he always said the witches broom is being pollinated cross-pollinated with the parent tree by the pollen or the neighboring tree, if they're the same species. He always said happen on average are going to be somewhat smaller than a normal seedling and the other half are going to kind of grow like a normal conifer. 

Ryan Welch: Okay.  

David Horst: So then over time he starts weeding them out because he can tell by that seedling after a couple of years if it's going to be a fast grower or smaller. And he was looking for the smaller sizes. 

Ryan Welch:  Yeah.  

David Horst: So he starts weeding them out in time. He can't raise thousands of them. You got to be selective. 

Ryan Welch: Exactly. But that got that kind of intuitiveness. It takes a whole lot of work and a whole lot of time and a whole lot of patience that a lot of folks just probably don't have when it comes to those kind of things. 

David Horst:  That's right. Because in all those years with those seedlings, you've got to water them, you got to keep them weeded. You got to pot them up to different sizes of pots. There's a lot to it. Wow. It's a year round. 

Ryan Welch: I was going to say it's not something that you just put in. You've put in a pot and put it in the corner of the sun and be like, okay, I'll make sure your watered every once in a while, and I'll be done with it. 

There's a little bit more to it than that.  

David Horst: Yeah.  

Ryan Welch: A lot of people also don’t realize, like you mentioned, pollen, you know, conifers are not pollinated because they don't have a flower. Like like flowering trees do a lot of deciduous trees. 

They're not pollinated by bees or wasps or birds, that's all wind pollination. And so whatever is blowing in the breeze that happens to hit at just the right time, that's what is going to be the genetics. That's half the genetics right there. 

Ryan Welch: That's right. You know, from one plant to the other. 

David Horst: Yeah. So you never know what you're going to get. 

Ryan Welch: Yeah, it's a mystery every time. 

David Horst: And that's what makes it exciting. 

Ryan Welch: I was going to say that that is where the interest is, is knowing that you don't know who knows what you're going to get here from this. 

David Horst: And that's how a lot of just fabulous plants have come about. 

Ryan Welch: So in terms of these dwarf conifers, like you said, they're not a lot they're not available in like your Wal-Mart or your Home Depot or things like that. You have to go to a collector to find them. And some of them can be propagated by seeds, by the cones, but a lot of them probably are propagation from the original cutting, correct?  

David Horst: Correct.  

Ryan Welch: Cutting in time, cutting upon cutting. Do they do any grafting or conifers don’t graph really well, do they? 

David Horst: Certain ones they graft and others ones they do rooted cuttings and seedlings, of course. And they are becoming more and more available at like the WalMarts, Lowe's, Home Depots. But still today, the best place if you're looking for dwarf conifers, is to go to a specialty nursery or a collector. 

People that raise them, just that's all they grow is conifers. Like Dennis Hermansen up at Farley, Iowa. He sells nothing but dwarf conifers for the most part. That's what his specialty is. 

Ryan Welch: Education is that the foundation of the Arboretum’s mission. And the Arboretum has the distinction of having the Heartland Collection classified by the American Conifer Society as a reference garden. This classification means that they are known as a place where people can come and learn about a large variety of conifers that can be grown in the area. 

As you said before, you guys are recognized by the American Conifer Society as the Heartland Collection. And that initially started with Chubb when he was the president of the American Cancer Society, correct? 

David Horst: That's correct. 

Ryan Welch: And since then, it sounds like you guys are a reference garden. What does that mean? 

David Horst: The American Cancer Society came up with this name, a reference garden to recognize noteworthy conifer collections throughout the country. Okay. So in all the regions they recognize us. They may like our region is called the Midwest region. 

Ryan Welch: Yep, which makes sense. 

David Horst: So we're part of that. I think we were like the third or fourth one recognized in our region at the time, in 2012. All right. But it's a way to educate people and promote conifers.  

Ryan Welch: Okay. So what's involved in becoming a reference. 

David Horst: Having a collection of plants available for public viewing and that are labeled. 

Ryan Welch: Okay, there's actually a certain number of plants or is it just as long as the properly labeled in the correct way and they can be used for educational purposes, you would qualify them as a reference garden.  

David Horst: Right. 

Ryan Welch: Okay. So there's no stipulation that you had to have more than five, less than so many, and things like that? 

David Horst: No, no. And I believe there's 51 of these total throughout the country. 

Ryan Welch: Oh, okay. 

David Horst: And we're fortunate to be one of three in Iowa. Oh, there's the Iowa Arboretum out at Madrid, kind of between Ames and Des Moines, which is a large arboretum. And the University of Iowa, the campus. Their maintenance crew has a reference garden designation. 

Ryan Welch: I do not know that. 

David Horst: They have a wonderful little garden there, kind of spread throughout the campus, but they have a couple of locations where there's denser plantings. And then, of course, Bickelhaupt Arboretum here in Clinton, Iowa. 

Ryan Welch: Wow. One of three in the state. 

David Horst: Yeah. 

Ryan Welch: So pretty big. 

David Horst: Pretty big. That's right. We're. We're honored. 

Ryan Welch: Yeah. 

Ryan Welch: Once the collection was established, the work did not stop there. This collection is continually being monitored and maintained, but also added to. As new partnerships are made, new plants are discovered, and new beds of conifers are being planted. 

So as you've been going over, you were made a reference garden in 2012, you've been keeping up with the maintenance of the Heartland Collection. What else has been added to the collection over the years. 

David Horst:  Over the years. We always attract conifer enthusiasts, collectors, collectors that come here and they collect wood. That was one of Chubb's stipulations when he made the proposal to the Bickelhaupts back in 1990, was that he wanted visitors to see the collection, and he also wanted it made available to collectors so they could collect Scion Wood. 

Ryan Welch: Oh, okay. So they can collect samples and propagated on their own as long as they do it correctly. 

David Horst: As long as they do it correctly. The stipulation was that they have to ask permission first whenever they come.  

Ryan Welch: Okay.   

David Horst: Yeah. So that we don't have any plants that are maybe small that shouldn't have any cuttings taken. 

Ryan Welch: If they're not ready yet or anything like that. Yeah, because you don’t want to damage what you've already got. 

David Horst: Right. And they're limited to what they can take. Usually we recommend 3 to 5 samples from a plant and that's depending on its size. We don't want a nursery man to come in and take off the entire top of the plant. 

Ryan Welch: No, we don’t want that. 

David Horst: So we limit on what they can do, with these collectors that come and collect the scion wood. There are some from Ohio had come in. A couple were friends of the Arboretum. couple were nursery men. They kind of gotten a tenancy coming every year. 

This was kind of their vacation. They'd come and collect wood and I'd spend a few hours up with them visiting and going over the plants and inevitably end up we'd talk about expansion or what we're going to do in the future. 

And sometimes they would also donate some plant material in return for us giving. 

Ryan Welch: It’s very reciprocal. 

David Horst: That's right. Very reciprocal. Well, one year back in about 15 or 2016, I was talking with the gentleman from Ohio and he said he had a proposition for us he'd be willing to donate some plants. He was a witches broom hunter and collected plants from all over the country, especially up in the Upper Peninsula area, and wondering 

if we'd be interested in that. So upon a couple of years of thinking about it, we came up with the location on the top of the hill, which is right after you walk into the collection. There was a open lawn area there. 

Ryan Welch: Oh, okay.  

David Horst: This gentleman and his wife donated 160 plants.  

Ryan Welch: Wow. That's a pretty nice donation. 

David Horst: Yep. Randy Dykstra and I from Fulton. We drove out to Ohio and picked them up. He donated all of them. And with the future promise, he's going to continue donating in the future. Randy and his wife, Karen from Fulton have donated quite a few plants also. 

So we thought it was only appropriate that we call this new area the Barger Dykstra Collection.  

Ryan Welch: Okay.  

David Horst: And that's how the name came about. 

Ryan Welch: That’s how that name, that little part of the collection. And it's still part of the Heartland Collection, correct? It's just like a subset. 

David Horst: That's right. And both Randy and Bill Barger were good friends with Chubb. Okay. And we know Chubb would be thrilled today. 

Ryan Welch: Yeah. If he were still around today, he'd be thrilled with the fact that you guys are expanding and you're adding new things, and you're still keeping all that enthusiasm and that education and that camaraderie about the whole collection up and going. 

David Horst: Yep. And a majority of the plants that have been donated by the Dykstras and Bargers have been, witches brooms.  

Ryan Welch: Okay.  

David Horst: Which is also neat, and ties in with Chubb's request. At the beginning he wanted some of the collection to be witches brooms. 

Ryan Welch: Okay, so it sounds like it all works out sort of in the end in a lot of ways. So are there any future collections in mind or are you just kind of at the moment waiting to see how things go? 

David Horst:  At the moment, we're waiting to see how things go. We're out of room now for the collection, so now we're kind of in the maintain mode. There will be some more donations from the Bargers, Dykstras because as they get growing in that area, that was in 2018 when we started the some of the plants are 

growing a little faster than we thought, so we're going to start transplanting some of them while they're still small enough out to the larger areas. And that'll free up space to get some more new plants that are miniature from the Bargers or Dykstras. 

Ryan Welch:  

Often with many disciplines. People like to gather and discuss the latest trends, new research or showcase projects that are near and dear to them. The American Conifer Society is no different, and they hold annual meetings on the national level every year, along with regional and state meetings as well. 

These meetings allow destinations such as the Bickelhaupt Arboretum to showcase all the hard work that they've been doing while also participating in an educational event that can benefit people on all levels and from all parts of the United States and beyond. 

As David explains, the Arboretum has been very fortunate in being chosen on a number of occasions to host these types of events. 

It sounds like as a part of the American Cancer Society you said they have, they have annual meetings every year. 

David Horst: They have annual meetings at the national level. They have a national meeting, which we were hosting until COVID changed our plans. 

Ryan Welch: So we were going to host it here at the arboretum. 

David Horst: We were hosting it here at the Arboretum and at Clinton Community College. 

Ryan Welch: So what’s involved in one of those national meetings that in terms of logistics and what that means for an arboretum of this size. 

David Horst: While we were going to be the host garden. Okay. So our Heartland collection or our dwarf conifers was the featured collection. And then there would have been four or five other tours. And most of these were homeowners that collect conifers. 

They would tour those homes. Down at Clinton Community College they were going to have a series of classes and lectures. Okay, that lasted for a couple of days. 

Ryan Welch:  For a couple of days, so you'd have a couple of days where you do have lectures and classes on conifers, on maintenance, on pruning, on propagation and all that kind of stuff. And then on some of those off times, you guys would then take tours of various collections, this being one of the main ones. 

But other collections in the neighborhood also were lined up to be given tours of. 

David Horst: Right, here in Clinton, Fulton. One of the tours was out on a farm by Elvira, and then there was a couple of tours down at McCausland, Geneseo and Moline. 

Ryan Welch: Oh, okay. So that's. That was a national conference. 

David Horst:  That was a national conference. That's the first time we ever hosted a national meeting. 

Or would have been if it hadn't been for the pandemic. 

David Horst: And generally, 250 to 300 people attend these and they come from all over the country, sometimes even from other countries, sometimes Britain, some of the countries in Europe, some of the serious collectors come. 

Ryan Welch: So they just have like one national conference a year, then. 

David Horst: One national meeting a year. 

Ryan Welch: One national meeting. Do they have any regional ones? 

David Horst: And then each region has a meeting a year also and usually they switch it up. This year might have been like in Ohio, next year it could be Indiana. The Arboretum has actually hosted a couple of the regional meetings over the years and. 

Ryan Welch: Probably come in, probably a similar format as the national ones just on a smaller scale. 

David Horst: Right? 

Ryan Welch: So you do some lecturing, some presenting and then touring of various locations. So people can see in your little part of the region what we're doing compared to other parts of the region. 

David Horst: Right. And then the next level down would be like they rendezvous, they call them, and each state can put those on. 

Ryan Welch: Oh, okay. 

David Horst: And I believe last year was the 21st year of the Iowa Garden Rendezvous, which we hosted also, where they didn't have the national meeting. They decided to have the Iowa Garden rendezvous. And it's ACS members, American Conifer Society members mostly, but anybody can attend and it's a lunch and then you tour gardens again. 

David Horst: Wow. So we were on that. 

Ryan Welch: You were on that list. 

David Horst: I believe that might have been the second or third time we were on that. 

Ryan Welch:  So it's a nice way for the these, these sort of national regional rendezvous type meetings are good ways for to get other people who may normally not come to this part of the state or even the country, for that matter, and showcase what we really do here, showcase all the work that's being done, not just in terms of the Conifer Collection, but all of the collections that are here on the on the, the acreage of the arboretum. 

David Horst: That's the goal. 

Ryan Welch: That's the goal. That's the hop. 

David Horst: Yeah. And it's worked pretty well. 

Ryan Welch: Good. That helps. 

As we have seen, the heartland collection of rare and dwarf conifers offers a unique learning opportunity for people of all interest levels, from the scholarly academic to the homeowner who's just looking for that one plant that may be perfect for that difficult to fill spot in their yard. 

This collection also gives people the opportunity to admire rare plants that had previously never been discovered or named until witches broom enthusiasts sought them out with the collection continued to be added to and modified, it means that with each new visit, there will always be something new that can be seen in this part of the arboretum. 

I would like to thank David Horst for his insight and enthusiasm with this podcast, and to Otis Welch for the musical selection.