KEN DRUSE AND I both love leaves, and so do the naughty furbearing herbivores who have been visiting our gardens with a vengeance this season—but that’s another story. Today’s topic is leaves to love from the gardener’s point of view, not the woodchucks’ or the rabbits’.
Ken Druse, friend of many years, and author and photographer of 20 garden books, including “The New Shade Garden” and “Making More Plants,” and most recently, “The Scentual Garden” about fragrance, is back to talk about what’s getting our gardens through the midseason slump: leaves, whether big and bold or fine-textured, and in a range of colors, too. (That’s Ken’s Syneilesis, above.)
Read along as you listen to the July 20, 2020 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).
Plus: Enter to win a copy of Ken’s book “The New Shade Garden” by commenting in the box at the very bottom of the page. That’s Ken’s leafy summer garden, below.
leaves to love, with ken druse
Ken Druse: Hi, Margaret. You started with the herbivores and I was already thinking of snails.
Margaret Roach: Oh, I guess they’re herbivorous, too, but they’re not furbearers.
Margaret: Yeah. And no four legs. How’s it going with the bunny patrol? [Laughter.]
Ken: Oh gosh. In the past we actually had one bunny at a time and people said that’s impossible, but I guess the baby bunny was dropped by a hawk or something, because that was when the bridges were grates instead of paved, and we didn’t have any animals because no animals could get on the island. But they paved the bridge…and anyway, this is the first time this has happened, but it’s like Australia. The hares are on the march.
Margaret: My Number 6, Woody Number 6, went into Witness Relocation yesterday. So yeah, yeah, yeah, yeah. Before we start, I should say that we’re going to give away a copy of “The New Shade Garden”–“The New Shade Garden” not meaning it just came out, but meaning it’s not your original shade garden book, correct?
Ken: That is correct. And it’s different. It’s not a reworking of the original, very popular book.
Ken: It’s a different take. And it has a lot to do with climate change, dealing with that.
Margaret: Yeah. And it has a lot of foliage in it. So I thought it’d be a good one for this topic to share with people. So we’ll have that with the transcript.
Ken: That’s nice. [Laughter.]
Margaret: Yes. And we’re also going to each gather and show off some leaves in the week ahead on Instagram, so I’ll give the link to that, too [Ken’s feed; or Margaret’s feed]. You also have been showing some incredible images lately of crazy things, including some really beautiful things with leaves like, I think it was a gold, variegated lily of the valley, maybe with-
Ken: Oh, yeah, sure.
Margaret: What’s that?
Ken: It’s a gold-variegated lily [laughter]… No, it’s a striped lily of the valley [above]. It’s just like the other one. I don’t know if it’s really quite so aggressive. I bought one little plant, which had three leaves, maybe five years ago, and now I could go into the business. This thing was $30. It’s probably $15 now, but I’ve got plenty of it, and it is beautiful.
Margaret: Yeah. Does it have a green pinstripe on the yellow leaf, or was it a yellow pinstripe on the green? I can’t-
Ken: Yellow lines on the green leaf, and they’re parallel with the way that the leaf goes. I don’t know what you call that. Striped. [Laughter.]
Margaret: Beautiful. I call it beautiful. I call it beautiful. So yeah, so foliage, so if not for the leaves, and I have to say with as dry as it’s been here, I don’t know if you’re as dry, it’s a little tricky to keep all the big-leaf things that are my particular obsession, happy. So leaves. What’s your thing in foliage, and why foliage? Maybe you should tell everybody why we’re both leaf-obsessed.
Ken: There’s so many reasons. I’m leaf-obsessed because, I love the way you put it in an email to me, I’m 60 percent sun at best, so it’s kind of a shady garden. And a lot of things flower in the shade, but it’s not the big showy flowers. So I depend on the foliage, and the foliage lasts three seasons.
Flowers sometimes, well, flowers are fleeting, maybe a flower the longest—two weeks would be incredible, something flowering for two weeks. There’s so many things in the garden that flower for a day. They don’t call them daylilies for nothing.
But I love the color and the texture and the form and the mass, and putting it all together, having something tall and skinny with dark green leaves, and something fat and round and bushy with lots of texture. And when I look out at the garden, it’s so incredibly colorful and there’s not a flower in sight, and I’ve got that for months.
Margaret: Right. Right. So I don’t know where we want to begin about-
Ken: Tell me about about your big boys.
Margaret: [Laughter.] The big boys. I don’t even know. I suppose it began with a plant that maybe I wish I’d never started growing, which was for sale at a local nursery several decades ago when I first started gardening here, Petasites. It’s x hybridis; it’s not actually japonicus. It was sold to me as japonicus, but it’s Petasites x hybridus. It’s a butterbur, I guess it is, from Asia. It’s big; tall, thick stems that hold up a very large, very, very large leaf, a couple of feet, few feet across. Green. It’s just green, but it looks like something you’d find in the rain forest or something, so very bold, almost tropical feeling. [Left edge of flowerless photo above: the Petasites in the backyard.]
And I brought home a pot of it a million years ago and put it in a spot in the backyard and it’s a very aggressive plant, it turns out, and again, this is decades ago, who knew, whatever. And so I have to trench around it or weed around it to keep it from going sideways everywhere. So I have this big circle of it in the backyard, which I love. And so I suppose that that was one.
And around the same time that got me addicted to the big leaves, and at the same time, a former botanic garden, that’s what used to be part of the New York Botanical Garden–the Cary Arboretum it was called at the time, the Cary Institute, now, of Ecosystem Studies–which is about 40 minutes away from here. But I was a weekend gardener, and it was on the drive; I passed it on the way, and I saw they had a plant sale one Friday, and I stopped in. And they had two plants that were in their garden, Astilboides [below], which has very big leaves in the shade, and Rodgersia, a cousin of it also, and I brought home pots of those two, so I think that’s where my craziness began: The bigger, the better.
Ken: All my life, knowing you, I thought that these were intentional things. [Laughter.]
Ken: I thought, “That’s smart, the way she planted that.” And you have the giant, which we used to call japonicus ‘Giganteus’ Petasites, or fuki, and I thought you had got that at the Japanese Stroll Garden, the John P. Humes, Japanese–
Margaret: In Long Island, no, I did not. I did not.
Ken: That’s where I first saw that plant, and people sell it, but with the wrong name, and it’s not that plant, because it’s actually very hard to find that plant that you have. See, I could sell my lily of the valley and you could sell your Petasites, but you have to tell people, in both cases, “This plant needs to be edited.” For the lily of the valley, I have it in a raised bed, in two raised beds actually, so it can’t go everywhere, although it wants to.
Margaret: Right. So, less precious, but very big and bold, I have a giant mass of rhubarb, just edible, plain old rhubarb, perennial, wonderful. Just a week or two ago, late June—I don’t harvest the stems early when they’re the most tender and small, because I love the look of the plant. And so I wait until a little later and I know that’s not, cooking wise, maybe they’re going to be a little more fibrous, but whatever. But it’s this big mass of it surrounding a bench on the edge of the vegetable garden, and to me, that’s just as beautiful. It doesn’t have to be a rarity. It could be rhubarb [below], I think.
Ken: I can’t grow Astilboides, don’t know why, and I can’t grow rhubarb. I think maybe it’s that you have more acidic soil, because my soil is alkaline. And we should mention don’t eat the leaves for the rhubarb. But also I’m going to say something you probably know. You can freeze rhubarb raw, and it just freezes great. You don’t have to cook it first.
Margaret: And that’s what I do when I cut it down again late June-ish, not as early as most people would, I cut it down and I dice the stems and I obviously compost the leaves, dice the stems, and I put them in bags in the freezer. And if there are still strawberries, I make some strawberry rhubarb compote for the freezer also. Or if there’s none, I just wait and use it later in something. But yeah, it’s great to have, and it’s so easy to work with.
But that gives you that big look of the tropics, even though it’s a bone-hardy plant that hails from Siberia originally.
Ken: Oh, that’s probably why I can’t grow it.
Margaret: Yeah. But I love that oddness of big, big, big in my cold zone. That’s I think what does it for me, but yeah, it wasn’t a deliberate intention. It just started with those couple of plants and then got to be a habit. But you have some big, bold things, too.
Ken: I do. I have Darmera, which is a native of California, but does just fine here. I have that Ligularia japonica, which for some reason, people don’t grow that. This is a mystery, because that’s an easy-to-grow plant, and I have it in a place where the snails would decimate it if they were interested, but apparently they’re not that interested.
But you have the big, bold leaves, and I have the pointillism version of texture and color and leaves. I have so many tiny-leaf things. All together they make a mass, like boxwood, but, well, the colors. The weeping pear, it’s silver. It looks like an olive tree until the leaves turn black and fall off, but that’s another story. [Laughter.]
Margaret: The Ligularia that you just mentioned, so to just describe it to people, how would you describe it?
Ken: Wow, that’s a good question.
Ken: Yeah. It’s lobed leaves and I guess they’re sort of palmy, like a hand, but they’re ferny. They’re feathery. [Above, detail of one of the large leaves.]
Margaret: Yeah, and big, big, big, big, big. So it’s a big mound of this, low down. And then right around this time of year, it sends up big tall stems with gold daisies.
Ken: Garbanzo beans. [Laughter.]
Margaret: Garbanzo bean pods, that then open into these gold daisy-ish things.
Ken: And every year, I think I’m going to cut them off and then I ended up liking them.
Margaret: Yeah, it has great seedheads, too. They’re crazy-looking. It holds onto its seeds.
Ken: It’s a wild and crazy plant.
Margaret: And the thing that’s great for me about it is it’s later. So I have this one big mass of hellebores, shiny, low, almost evergreen leaves. People know what hellebores are. But it was just a monotony, eventually, and so when Ligularia japonica came into the market or whatever, I bought a few plants and I tucked them in every so often in that sheet of the lower, evergreen, shiny-leaved hellebores [above].
And it’s matte-leaved and very textual and very big leaves, quite different and higher up, and it gives me a second season and a second dimension in that same bed. So sometimes you can take one of these big-leaf plants and interrupt a sheet of groundcover, so I think it’s great for that, too.
Ken: You’re talking about groundcover and I have, in dry shade, Brunnera macrophylla, and some of it looks like ‘Jack Frost’ [above], which has silver lines on the leaves. And it’s a carpet of Brunnera, and it blooms in the spring with wands of wonderful blue flowers. But I’m surprised—I never thought that plant was going to act like this. It’s just a complete groundcover and the weeds don’t come up in it, and it’s beautiful. I’ve tried all the different, very hard-to-grow kinds. I don’t know, do grow some of the Brunnera, the perennial forget-me-not?
Margaret: Not really. I’ve tried over the years a few times, and this is a terrible thing to admit because I know it’s such a treasured color, but I don’t really have much that’s blue. I’m not a blue person. I have one blue. I have a lot of purple things, but the true blue color, like the Brunnera flowers you said are blue I have Mertensia, what’s the common name for that? Mertensia virginica. Bluebells, Virginia bluebells. I have that, which has a blue flower, but I don’t really have much else that’s blue-blue. So yeah. So they didn’t really fit with my raucous color scheme, I guess. I have a lot of other weird colors, mostly.
So you said you have a lot of little things and more pointillist and so forth, so some examples?
Ken: [Laughter.] Well, I guess about the tiniest is Arctic willow. Do you know that Salix?
Ken: And it’s very blue, but not blue flowers. The leaves are blue, and I trim that every spring before it leafs out, and then it just makes this cloud of silvery-blue. That’s a wonderful plant.
Margaret: Does it have… I don’t know what the species is. I can’t remember. Do you remember? I’ll look it up for the transcript if not. [Above at Ken’s, Arctic willow above red leaves of a Japanese maple.]
Ken: It’s Salix something nana, purpurea… It’s an odd name, Salix purpurea ‘Nana.’
Margaret: Yeah. So that’s fine-textured, but very distinctive,
Ken: Very fine-textured. And I was trying to think of, do you remember a plant called Eleutherococcus?
Ken: Is that its name? That plant got is name changed.
Margaret: I think it has a different now. Yeah, Acanthopanax.
Ken: Acanthopanax, Aralia, it’s had so many names, but you can find it under Eleutherococcus sieboldianus ‘Variegata.’
Margaret: Whatever that means. [Laughter.]
Ken: It’s got thorns, but they’re like maple leaves almost. They’re five-lobed, very fine texture, I guess inch and a half across, and it just covers itself in these beautiful variegated leaves, with a lot of variety.
Margaret: It can even be trained up a wall or as a, what do you call it—an espalier flat.
Ken: Oh, that’s a good idea.
Margaret: Yeah, it’s great against a dark wall or something.
So, leaves: wanting the leaves of something and wanting them maybe… There’s a lot of trees that have beautiful leaves or large shrubs that have beautiful leaves, but if we want to bring that foliage down to more at the garden level, not up high, do you grow any cutback shrubs or tree-ish like things that you cut back and keep smaller, so that you have the foliage on new shoots?
Ken: I do. I have a Catalpa that I cut back. I have Paulownia, but that’s a totally different, although talk about big and bold. Do you know Paulownia?
Ken: So I have a Paulownia that’s probably 15 years old, and every year in the spring, I cut it to about four inches and it produces a juvenile shoots with leaves almost 2 feet across and it goes up 15 feet or so. It goes to the second story of the house, easily, and people stop and say, “Where’d you get that sunflower?” I say, “It’s not a sunflower.” And it’s a bad weed.
Margaret: It’s a terrible weed. It’s a tree.
Ken: It’s a tree.
Margaret: People may have seen it along the highways. It has beautiful purple-ish flowers and so-
Ken: Not if you cut it back.
Margaret: Right. So you’re growing it in the way that it’s not invasive, because you’re growing it as a cutback shrub. And the Catalpa, would that have big leaves, too, at an early age?
Ken: Yeah, not as big. And the one I have is gold. I guess the leaves are just under a foot across, and they’re heart-shaped leaves. After we end talking to each other, I’m going to think of 40 things that I cut back for that effect.
Margaret: Right, because I don’t, really, I don’t do that so much, and I keep thinking, “Why don’t I do that?” Because in great gardens that I visited, that’s always a feature of, again, a way to bring the great leaves from a tree that would be 30 feet up in the air, to bring them down to the garden level, and often at a larger size.
Ken: I don’t want to put you on the spot, but can you think of a couple of things that you might do that too, or want to or have-
Margaret: Well, the two that you just said were ones I wondered about that—the Catalpa, especially, because I see catalpas around here. I know they’d work. I see them as trees.
Ken: And I cut back that willow that we talked about, but you have to be sure that the plant you’re cutting back has dormant buds, because you could cut back the wrong plant, and that would be it, so you wouldn’t want that. [Laughter.]
Margaret: Right. But I think that the expression in traditional horticulture was, “Cutback shrubs,” or, “Growing something as a cutback shrub,” so I think if we look that up, we’re going to get a good list. People, if they want to investigate for their area, that would be the expression I think, is cutback shrubs, right?
Ken: Yeah, or a cutback.
Margaret: Right. A cutback. Right, right.
Ken: You can call it stooling. It has a lot of names. People used to cut back things like willows to make firewood because they harvest it from plants that had endless dormant buds. They would cut them back, harvest the twigs in two years and cut them back again and just have wood.
Margaret: Right. Or to make a fence or to use for-
Ken: For wattle.
Margaret: Right. Right. Another kind of, besides the bold plants, one of the other things that I’m particularly interested in in foliage is at the beginning of the season-
Margaret: Oh, you know what I’m going to say. The ones that come up, these unearthly-
Margaret: …colors like reddish and bluish and purplish, “not green,” as I say, plants that emerge not green.
Ken: So you’re going to tell me what that is. It’s something like “acannocyanins” or something.
Margaret: Anthocyanins are the pigment.
Ken: Anthocyanins, oh, I was close.
Margaret: So not chlorophyll, but anthocyanins. And we think of those, those blue and red pigments as fall colors. When the chlorophyll fades, we see those, but in some plants, they have it early in the season, maybe because it tastes bad. And so it’s a way to prevent predation by herbivorous animals and insects, maybe, that’s one of the theories.
Ken: I thought it was an antifreeze.
Margaret: Yeah. I don’t know. I know there’s various things that it may do. It help may help to absorb more light during the short, leafless season in the canopy above, blah, blah, blah. But whatever, I’ve read a million research papers on it. But some peonies have that, Jeffersonia, the twinleaf, a native wildflower. Bleeding hearts even have it. I’m just interested in that as, in other words, to enjoy the foliage at ground level when the garden is awakening as an extra show from things.
Ken: Well, we’re talking about three seasons, certainly.
Margaret: Yeah, yeah. Any new acquisitions?
Ken: Well, I thought of something I cut back that I forgot, Cotinus ‘Grace’ [above].
Margaret: Oh, yes.
Ken: All the Cotinus you can cut back. What are they called, Cotinus? I’m terrible-
Margaret: Smoke tree.
Ken: Well, ‘Grace’ is a hybrid between the European and the American and it has big, iridescent leaves, and that’s a great cutback and it just shoots up.
And I think some of my favorite variegated plants, I love the Symphytum x uplandicum ‘Axminster Gold.’ Do you know that plant?
Margaret: You’re coming up with some Latin stuff goin’ on here today [laughter].
Ken: It’s comfrey.
Margaret: Yeah, Symphytum is comfrey. Yeah, yeah.
Ken: Right. And you know the plant that we both like and have trouble saying, do you know which one I mean? The Syneilesis [photo, top of page].
Ken: And there’s two of them. There’s aconitifolia, which I think is the better one. There’s three, because there’s a hybrid, and palmatum or something is the other one, but aconitifolia, which means it has foliage like an Aconitum, and what’s that, monkshood?
Ken: So that’s almost indescribable, and it’s in the daisy family, which is bizarre, to say the least.
Margaret: That’s a real “it” plant right now. Syneilesis or however we say it. So it’s S-Y-N-E-I-L-E-S-I-S, Syneileisis, And it’s really hot, hot, hot right now.
Ken: I saw that plant probably 20 years ago when it was first discovered—“discovered,” brought from China—James Waddick, Dr. Waddick brought it and he was calling it rabbit umbrellas, but I don’t think that’s what they call it anymore.
Margaret: That’s hilarious. Rabbit umbrellas. It’s so textural. So, so much like a doily or a lace, you know what I mean? So open and, oh, it’s incredible looking. So we’re going to have pictures of all these, of course, people, I know we’re just ranting, but lots of pictures with the transcript of all of these. Yeah, that’s a great one. And again, when I first got the Astilboides, or the Rodgersia [above, at Margaret’s], those were “it” plants at the moment. They weren’t so widely available and this is a new one for unusual foliage. Yeah, yeah, yeah.
Ken: Do you have anything silver?
Margaret: I used to have a lot of silver things and I don’t too much. I have a big willow, which is the rosemary willow, Salix eleagnos, which is a silver, long, a very linear, thin leaf, and I’ve let it grow into a tree, so it’s a very unusual one. So that’s a big silver mound.
Ken: I love that plant, and why did they change it’s name? Rosmarinifolia or whatever it was, or rosmarinas, that was the perfect name. It looks like rosemary.
Margaret: It looks like a giant rosemary bush.
Ken: Well, they changed the name. Of course you need sun for silver things usually, but I have one Artemisia ‘Silver King’ [above], that does quite O.K. in the shade and it’s not a monster in the shade, and I have a terrific Pulmonaria, a lungwort, no one calls it that. Pulmonaria ‘Majeste,’ and the leaves are really silver. And if you’ve ever grown that plant, any of those plants, after they bloom with, again, blue flowers, some of them—there’s pink and there’s white—you can cut that plant back to about 2 or 3 inches, 2 inches, and it’ll flush all new growth and you’ll have the beautiful foliage again.
Margaret: Yeah, well Ken, we could obviously go on for three or four days talking about leaves.
Margaret: Because we’re totally leaf-mad, but-
Ken: Do we have to leave leaves?
Margaret: We have to leave, oh boy, here he goes again, folks, with the—oh boy—the jokes. [Laughter.] Yeah, so on that note, I’ll hang up on you. Nice to speak to you. Thank you so much.
Ken: Thank you.
Margaret: All right.
Ken: I’ve got to post these pictures.
Margaret: O.K., talk to you soon.
enter to win ‘the new shade garden’
I’VE BOUGHT an extra copy of Ken Druse’s “The New Shade Garden” to share with one lucky reader. All you have to do is answer this question in the comments box at the very bottom of the page (after the last reader comment):
What are some of your favorite foliage plants of all, and why?
Feeling shy, or have no answer? Just say, “Count me in” or something to that effect, and I will, but an answer is better. I’ll pick a winner U.S. or Canada) after entries closed at midnight Tuesday, July 28, 2020. Good luck to all
(All photos except rhubarb, Astilboides, Rodgersia, Petasites, Ligularia copyright Ken Druse, used with permission. Disclosure: Purchases from Amazon links may yield a small commission.)
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MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its 11th year in March 2020. In 2016, the show won three silver medals for excellence from the Garden Writers Association. 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 20, 2020 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).