CAN A HISTORIC formal space become the home to a forward-thinking landscape of native plants? The team at team at Stoneleigh, a five-year-old public garden on an old estate in Villanova, Pa., says the answer is an emphatic yes.
And their horticultural experiments seem to prove that’s true.
Its director, Ethan Kauffman, and I spoke about how he and his team are reinterpreting the grand old landscape with a natives-only ethos that was handed down to them by the nonprofit called Natural Lands that conserved the place.
Two-dozen kinds of native vines now climb the majestic century-old stone pergola at Stoneleigh, and space-defining hedges of white pine and American arborvitae, or dwarf Magnolia grandiflora, are among those redefining the 42-acre landscape. There’s lots of other lessons for home gardeners, too.
Read along as you listen to the July 10, 2023 edition of my public-radio show and podcast using the player below. You can subscribe to all future editions on Apple Podcasts (iTunes) or Spotify or Stitcher (and browse my archive of podcasts here).
natives in a formal setting, with ethan kauffman
Margaret Roach: Yeah, so we did a “New York Times” column together, and that was fun. And learning about what you’re doing down there at Stoneleigh, really reinterpreting this historic space. And as I said in the introduction, with this native mandate. It’s very, very exciting, and I think it really does apply to home gardeners who are wondering, yes, but how do I use these plants? I knew how to use hostas and Astilbe; now what do I do [laughter]? So how long have you been there and how long has this been open?
Ethan Kauffman: I’ve been at Stoneleigh for about seven years. It’s hard to believe, but I started in 2016 towards the end, and the garden has been open five years. So we’ve been in the landscape for all of the seven years, really. And it’s been such a joyful experience. This place was gorgeous when we got here, and we had this incredible opportunity, as you said, to transform it to a garden that not only serves as a place of relaxation and rejuvenation for our guests, but also supports all our local wildlife and ecology and get to have fun doing it.
Margaret: And it’s free. It’s open to the public except for, I think, Thanksgiving and Christmas, and what? On Tuesdays to Sundays, is that right? But it’s free. It’s free of charge, which is just fantastic. So welcoming, literally.
Ethan: It is. And I think when you walk into Stoneleigh, you feel that welcoming spirit, that sort of comfortable, accessible energy. And maybe it’s the huge trees. We have so many really old, big trees here, and you feel, I don’t know, I feel sort of the sense of safety and comfort under their boughs. So it’s really a special place.
Margaret: So this was more than a century of history before you all got there. I mean, this was an estate on the Philadelphia Main Line. And tell us a little bit about what you inherited. Because there’s this mansion, just there’s some remnants, yeah?
Ethan: Oh, absolutely. And for millennia, of course, this was cultivated by the Lenape tribe. And then when it was colonized by Europeans, it was agricultural till about the 1870s. And this area of western suburbs of Philadelphia called the Main Line has all these estates that were built during the country place era, from 1870 to 1930, and Stoneleigh’s one of those grand old estates. And it was a really magnificent and is a magnificent place. It was designed in large part by the Olmsted Brothers, from about 1906 to 1955. So we really had some great, great landscapes to work with.
Margaret: And what I remember when we first talked, when we did the “New York Times” interview and we were just getting to know each other, you told me that when you got there, there were seven acres of pachysandra and I think 14 of mown lawn on this 42-acre property [laughter]. So that’s not very ecological or that that’s quite the opposite of what your mission was, and is.
Ethan: Yeah, Margaret, I’m not kidding. When I first walked in there and I saw that pachysandra, I said, “Oh my gosh.” And turf. And in the first, I think, month, there were just two of us at the time, and we saw this pachysandra; we were just so ready to get rid of it. So we didn’t have any equipment, so we rented this mini-excavator and the two of us took turns and we ripped out about an acre of it, which actually became our parking lot. So it was very satisfying that first removal of pachysandra. We’re still chipping away. I can promise we’ll be at it for a long time, but I think that’s what makes this place accessible too. We have a small team, it’s not happening right away. And so our guests and the people that come in our community can see this transformation take place before their eyes. And it’s very relatable to what they’re doing at home.
Margaret: And with all that lawn, you didn’t get rid of it with the excavator like you did with that one acre of the pachysandra, you are treating it differently, or managing it differently.
Ethan: Lawn is such a big part of American culture, and we all know that it’s difficult on our resources, especially water, and it’s not particularly productive for wildlife. So with 14 acres, we knew we had to do something and we quite literally accomplished our goal by doing nothing. We stopped mowing about half of it. We leave about six feet on the edges to make it look like it’s cared for, but then the rest of it grows really beautifully in this sort of 18- to 30-inch-tall, meadowy mix. And as soon as we started doing that, we saw birds flying in there, even foxes jumping through it. And so we knew we were on the right track.
Margaret: And that, just like what you said, that leaving the edge mown just says, “We’re here, we’re doing this, but we’re doing it in a gentler way,” which is really important. I’ve definitely been experimenting with my areas of turf, which parts can I unmow and make it look like part of the plan as opposed to just, “Oh, she’s being messy.” [Laughter.] So yeah, it certainly looks beautiful in the photographs I’ve seen of Stoneleigh and the lawns.
So sometimes people, one of the hard things about transforming parts or even more of our gardens to native plants, is sourcing the plants. And one of the things I loved hearing was that you go on adventures in some of the other nature preserves, some of the other preserved land, that Natural Lands, the organization that made this Stoneleigh transition happen, that they have under conservation as well, or under management and care as well. And you get seeds from local, regionally appropriate local natives, and I don’t know, cuttings I suppose, and who knows what, and grow those. So tell us just a little bit about that.
Ethan: It’s really special, because Natural Lands organization that we’re part of, also has 42 other nature preserves. About 23,000 acres that we get to roam, and they’re some of the most beautiful properties in the entire region, in southern New Jersey and eastern Pennsylvania up to the Poconos. And we have coastal properties. So if you’re looking for native plants, we really can find so many wonderful examples of the diversity that’s in this region. And it’s awesome. Who doesn’t love getting out into the woods? And if you’re collecting seeds to then bring back and showcase to our community, it’s even better, I’m telling you. It’s a really fantastic opportunity for us. And we hope everyone enjoys seeing these plants that they might not normally see, or they might be familiar ones that they didn’t even know were part of their local ecology and landscape.
Margaret: Right. It’s pretty exciting stuff. And for me, one of the most exciting things of all was to kind of hear about, here again, you have this formal place, there’s this, what is 220-foot-long, stone pergola that’s like this magnificent century-old or older structure, this amazing thing, but it had nothing growing underneath it. I think you said there was turf and nothing growing up and over it. And so you’ve with that and other spots on the property, espaliers on the walls of the estate house and other places, you’ve kind of done this whole vertical thing, and not just with vines. You’ve sort of gone vertical [laughter]. So tell us about some of those efforts. Because boy, oh boy.
Ethan: We have gone vertical. And it’s funny because that pergola, before there’s anything on it, the number one question we always got, “What’s that for? What’s that thing for?” And I would say, “Well, it’s a promenade. And have you ever seen that show “Bridgerton” on Netflix? [Laughter.]
Ethan: Yeah. So that’s made it much more relatable, because now people are much more familiar with promenading. So it’s a place that you would walk, a romantic place. But once we got these vines on it and planted it, and you could see this really romantic structure really revealing itself with the vines, people totally get it, and it’s a great opportunity to showcase some of these vines. People are often afraid of vines, but that’s what makes them so appealing. They’re unpredictable. They can just grow in all these varied directions. And if we put them in the proper places, or new places as you mentioned, then they can be spectacular additions.
Margaret: And you probably had to do a little homework, because off the top of a gardener’s head, they might not think of a whole lot of different native vines. I mean, they might know the trumpet honeysuckle, Lonicera sempervirens. They might know about that, or one or two. But it’s not like we all have a palette at our fingertips of, hey, what are my native vines? But you have figured out a lot of them to include. Yes?
Ethan: Yeah. It surprises some people to know that we grow about 100 different varieties of native vines here. And I think my top three, I’m going to have to say crossvine is Number 1 [coral-colored vine, above, on estate house].
Margaret: And so what’s the Latin name for crossvine?
Ethan: The Latin name? Bignonia capreolata.
Margaret: Bignonia. O.K. And does it have kind of orangey flowers, or coral-colored flowers?
Ethan: It does. And it’s mostly evergreen in the north. Definitely evergreen in the south. Has these big, beautiful orange trumpets. There’s some red varieties, there’s now a yellow variety out there. It’s really beautiful. And we’ve got this crazy variegated one, it’s called Bignonia capreolata ‘Variegata.’ And it’s like no chlorophyll. It’s almost white at the tips. And it flutters in the breeze and I’m thinking, how is this thing feeding itself? But it’s pretty spectacular, too.
Margaret: And so you’re using that, is that some of that on the pergola? And is some also elsewhere being used vertically elsewhere?
Ethan: It is. It’s on the pergola. We also have one of those on our trees. So we have all these really tall trees. And when we see these bare trunks, we think: What an opportunity to, as you said, to go vertical. Because it really extends the garden in a different plane. And not only that, but it’s great for, it creates a vertical highway to the canopy of trees for insects, for reptiles, for birds and mammals. So many great things come by using vines in the garden.
Margaret: Right. So that’s one of your favorites. And any others? I mean, I mentioned the honeysuckles and I love the trick, well, the sort of design trick you have with those. Tell us about those. And also with the, what is it called, the trumpet creeper, the Campsis radicans, how you use the multi-colors of them together.
Ethan: Coral honeysuckle is my Number 2 favorite native vine, the Lonicera sempervirens. And we’ve had some fun with it. We take in three flower-color selections, a yellow and orange and a red, and we put them in the same hole in a couple places on this pergola. And it’s all grown together. When it flowers, it looks like fireworks. It’s like this explosion of different colors. And it’s fun. We’ve done the same thing with the Campsis radicans or trumpet creeper. Same colors, orange, red and yellow. And then my third vine, I’ll say is wisteria, is my third favorite. For flower power that is.
Margaret: But not the wisteria that so many people have, which is an Asian species that’s actually quite invasive. So that’s not what you’re talking about, correct?
Ethan: No, we’re using the American species. And the Asian species, and I lived in the south for a long time, and Chinese wisteria has wreaked havoc on the ecosystem. So we need to get away from using those non-native varieties and stick with the native ones, which are actually much more behaved, relatively, for wisteria.
Margaret: And I think it’s frutescens? Is that the species of wisteria? Wisteria frutescens? Is that right? Did I make that up?
Ethan: That’s one that we use. And we use macrostachya, too, which is more central, south central United States.
Margaret: Oh, I didn’t know there was more than one. See, this is the thing, is that we have to do our homework because, and go exploring if you have 42 nature preserves [laughter].
Margaret: Because it’s not so obvious and it’s not in every nursery. All these things are not in every nursery, right?
Ethan: No, no. It’s important to get out and explore. And that’s where public gardens and nurserymen and women really can advance horticulture and landscapes, both public and private. And by the way, the macrostachya, I really like almost better than frutescens because it has much longer panicles of flowers and it’s slightly smaller.
Margaret: Didn’t know, had no idea. And then you’ve also incorporated a number of native clematis vines, I think, as well onto the pergola and elsewhere.
Ethan: We have, and I’m sure you’re a lover of clematis, too, because of the way it’s a little bit more dainty than most vines. You can let it ramble on shrubs, on especially evergreens, it looks great on smaller evergreens. It can just kind of weave through the foliage. And then those flowers, which are spectacular, really kind of stick out against the green.
Margaret: Yeah. The thing that’s great also, is that you, guys experiment. You push the plants to do different things. And so on that pergola, you have some shrubs and well, some trees that, so in other words, not vines yet. You’re training them, upward pruning them and encouraging them to go up on the pergola. So tell us about that, because I think that’s something that a lot of us don’t know how to do, that other woody plants can be encouraged to behave in a vertical manner as well.
Ethan: Plants are something that we can really use our imagination. And what’s so fun about horticulture and is this mix of art and science, and so we can manipulate plants in all these different ways, but they do follow real world rules of nature. So we do have to be cognizant of that.
But we’re using yellowwood, which is a weeping variety called White Rain, Cladrastis kentukea ‘White Rain.’ And we’ve leaned it against the pergola and are training it across the top. And if you’ve ever seen yellowwood flower, it kind of does it every three years; it’s pretty shy. When it does, they all flower once it seems like. And so that has these long panicles of white flowers, almost like wisteria. You get a wisteria effect when these things hang down through the pergola,
Margaret: Huh. Yeah. And I think some other weeping, maybe a weeping redbud, a white-flowered weeping redbud, if I recall correctly, you’ve used that. You’ve trained that in a less tree-like way as well.
Ethan: We’ve trained that on some of our columns throughout the garden, so just we’re wrapping it around. Cut off the lateral branches, and then when it flowers, you get these white pea-like flowers against the stone. Or espaliering redbuds on the walls of the house, too. And so we’re taking this plant that’s known for its flowers and using it in all these different ways. And that’s why I think for us, cultivars are very effective, because it really opens up the use for plants and the landscape and all these different ways that can be dwarf, maybe columnar, they can be weeping. But it allows a lot more diversity in how this native plant can be used.
Margaret: Well, with the redbuds, there’s some of the cultivars that have the dark foliage. Have you used some of those? Purple foliage.
Ethan: We love those. Yeah. One, we have one called ‘Black Pearl’ on the side of the house, and we use ‘Merlot,’ ‘Forest Pansy’ and a number of other different varieties. The redbuds have really exploded, haven’t they? There’s so many different cultivars out there now.
Margaret: And so to espalier them, you are training the branches by, you’re pinning them in your case to stone, or it could be other siding, or it could be a trellis or whatever. You’re using eye hooks or something and wire, or what are you doing?
Ethan: We’re drilling right into the mortar. We just take a drill, hammer drill, and put in the eye hooks, screw them in there, and start slowly and small and get your main branches, the framework, in place. And then you’re just trimming the lateral branches and then thinning it in the center as well, to kind of expose the inner sort of architecture of the limbs.
Margaret: I have a friend who loves… He’s an expert horticulturist for many years, and he loves to espalier things, and he has witch-hazels and all kinds of things espaliered against, he has a board fence, a flat, almost like a wall-type fence, around his garden. And it’s just, I just am like, oh my goodness, look at that. I never thought to do it with what he does it with. And you have the same sort of instinct, which is to give it a try. So if I wanted to do, say, witch-hazel, and I believe you’ve done some, what do I do? I reduce the number of main stems first? Or you start with a young plant, I guess, first of all, don’t you?
Ethan: Yes. Well, first of all, I think your friend and I would get along really well, by the way [laughter]. I love the espaliering witch-hazels. So yeah, you start with the young plant. I think that’s probably the most important thing. And honestly, sometimes you see a plant in the nursery, and it could be a little bit misshapen from an accident or something else, and maybe one side of it’s gone. And a lot of times plants will kind of inspire you to use them in certain ways. So sometimes you’ll see one, but it’s like that is already flat on one side, so it’s half the work is already done. If you don’t have that, you can simply trim the back branches off and the front, and you almost make it two-dimensional. And then start small, as you said, and simply cut the branches that grow out away from the ball off, and attach the ones that are growing laterally in ways, in the pattern that you want.
Margaret: Yeah. Because when I see it in a formal garden, or there’s an orchard near me and a woody plant specialty nursery not far from me, and the person there does beautiful espaliers with fruit, with different varieties of fruit trees and so forth. And they’re just so beautiful. I mean, they’re irresistible. They’re just gorgeous. And yet, I think we gardeners, average home gardeners, that think, “Oh, I couldn’t possibly do that.” But what you just said is all it takes, right? [Laughter.] I mean, yeah.
Ethan: It’s really pretty easy. It seems complicated, but I think when you’re starting out gardening or even experienced gardeners, sometimes we’re afraid to make mistakes, but I think we’re really lucky that gardening is so forgiving of mistakes, of what we do wrong. And so it’s almost part of, not almost, it is part of gardening and the growth, and what creates so much of the magic of what we do. So I would just encourage people to take a leap of faith. Go for it. If you mess up a little bit, it’ll probably be fine. They’re plants and they grow back. It’s like hair, right?
Margaret: Yes. Usually, usually. And so we’ve talked a little bit about vines and things you treat as if they could be vine-like, but conversely, you have also trained some vines like the American wisteria into shrubs, haven’t you?
Ethan: We have, and that’s been a lot of fun. Sometimes people might want to use a plant like wisteria in their landscape, but they might have a small property, so you can prune it like a shrub and keep it in a smaller space. We’ve done that with woodvamp, Decumaria barbara, as well, and currently have one going with American bittersweet, Celastrus scandens, as well. Easier with these woody vines that are kind of bigger and heftier.
Margaret: And so again, do I start with a young plant and stake it up or something? Or what do I do to get going?
Ethan: Staking it up is a great first step. Identify your central leader and then remove, again, it’s kind of like this value thing: Just slowly over time, remove these smaller branches and focus on perhaps three or four main branches to be the structure of this plant. And then with the wisteria, we trim it right after it flowers because it sends out those little tendrils, you know how it does. Cut those and then throughout the year, you can sort of just snip them back, too.
Margaret: I just wanted to ask you about some of the hedge creations you’re working on, because that’s the other thing is this is, again, this 42-acre longtime estate with a lot of history to it. And yet it was very open, you told me, when you first came there and there weren’t a lot of defining hedges and so forth. And you are doing that not with the usual suspects, yew and privet (goodness forbid) [laughter], but you’re doing it with native plants. So what are some of the hedging specimens that you’ve had some success with, that you’re liking. What’s happening?
Ethan: We are using a lot of different things, and it’s, again, like espalier, you really can, if it’s a plant that takes well to shearing or pruning, you can hedge it. And so that’s our approach. We’ve used a dwarf variety of Magnolia grandiflora called ‘Teddy Bear,’ and it’s really beautiful, about 16 feet tall. It has these tight inner nodes and really glossy leaves. It’s been a beautiful hedge.
But we’re really into creating mixed hedges as well. And so we like that because with one species in a hedge, it might be beneficial to far fewer animals than a mixed hedge. So it also creates a more resilient plant or planting in the landscape, so if disease affects one plant, it’s not going to affect them all, hopefully. And so we mix all these different things. I found that Viburnum dentatum, arrowwood is really wonderful. Carpinus [C. caroliniana, hornbeam] is really wonderful.
But we’re doing things with redbuds, too, putting them in these hedges. And American styrax, Styrax americanus, we’re putting those in hedges, and Hydrangea arborescens, and of course all the evergreens like Thuja, arborvitae, they work well to mix in. But I think you can let your imagination run wild for the most part.
Margaret: And so these are like bio-hedges. These wild hedges that include, like I said, they can have multiple species and, yeah, interesting. So it’s like a mosaic, like a living mosaic. Interesting.
Ethan: The key is to shear them, to make them, again, same thing with cutting the 6-foot strip at the edge of the no-mow. And you just want to make sure that it’s understood that this is intentional and cared for. So shearing it, and keeping it tight really makes it more legible.
Margaret: So do you plant them extra-tight compared to if they were just a single specimen? Do you plant them a little tighter than you would?
Ethan: We don’t plant them any tighter, but it’s funny because people will see our hedges and they say, wow, it looks like they’re so tight. I’m like, well, if you were planting arborvitae, it would be the same distance. So I think it’s just this getting used to a different palette of plants for hedges.
Margaret: Interesting. Well, Ethan Kauffman, I’m really, I’m just so impressed with what you’re doing at Stoneleigh in Villanova, Pennsylvania, and just also really struck by the fact that it’s so welcoming and even free to the public and so forth. I’m so glad that we were introduced and I’m so glad to learn more. So thank you for making time today. Now go out and make more hedges. I hope I’ll talk to you soon
Ethan: It was a pleasure to be here. Thank you.
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MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its 14th year in March 2023. It’s produced at Robin Hood Radio, the smallest NPR station in the nation. Listen locally in the Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) Mondays at 8:30 AM Eastern, rerun at 8:30 Saturdays. Or play the July 10, 2023 show using the player near the top of this transcript. You can subscribe to all future editions on iTunes/Apple Podcasts or Spotify or Stitcher (and browse my archive of podcasts here).