WHAT KIND OF SCENTS that plants offer up please you, or don’t? How do you even describe what things in the garden smell like? I spoke with Ken Druse, author of the new book “The Scentual Garden: Exploring the World of Botanical Fragrance,” about his fascination with fragrant plants.

There are a lot of good things I could say about having known Ken for many years, and one of them is that we’ve had each other to talk to along the way while we’ve been writing each new book, someone to ruminate with and refine ideas with, time and again. So when Ken started telling me more than a year ago about what is now his latest and his 20th book, about fragrance, I was fascinated because frankly it’s not something I know a lot about. Now, thanks to Ken and “The Scentual Garden,” I do.

Read along as you listen to the October 14, 2019 edition of my public-radio show and podcast using the player below. You can subscribe to all future editions on iTunes or Spotify or Stitcher (and browse my archive of podcasts here). Plus: enter to win a copy of the new book in the comments box at the bottom of the page.

fragrant plants: a q&a with ken druse

Ken Druse: Oh Margaret, what a nice introduction.

Margaret Roach: Oh, I just pretended that that was all true. [Laughter.] But no, seriously, I mean we’ve read, and talked about, and developed ideas. We’ve told each other, we’ve confessed, “I’m thinking about this, I’m thinking about that.” Or, “What do you think about this?” “What do you…” We’ve done that for a few years now.

Ken: Just a few, right?

Margaret: Yes, yes. So, so thank you for the new book and for really for getting me to even think about this, because I have to say: I could tell you which plants in my garden have a scent that I like, but that’s not why I got them. It’s not that I was motivated by it. So I want to hear more about how this all came about.

The book is beautiful, and big. So why did you want to tackle the topic of scent in a book? Because it’s not an easy thing, to talk about smells. [Laughter.]

Ken: Well that actually, that’s kind of the reason I want him to do it because I, well I love fragrance, and I have a rather acute sense of smell. Whenever I meet any flower, no matter what, even if it’s a dahlia, and I think “That’s not going to smell,” I have to smell it and check it out and test it. And when I find something that smells, it’s just wonderful. It’s like another dimension, to me. And when I see something like a rose that doesn’t smell, that’s a letdown, for me anyway.

But I look in the catalogs, some of the best catalogs or on some of their websites that describe plants—even the best ones—and when it comes to smell, it says “fragrant,” or it’s doesn’t say anything.

Margaret: Right, right, right.

Ken: And I wanted to know what it smells like, or how can one describe that? And that’s what I set out to do is to describe fragrances of many plants—well, plants that I love.

Margaret: It was interesting for me. I recently, since I first read your book, as you were kind of working on it, and then read it just when I got my early copy recently, I’ve also been reading this other new book, not a garden book at all. What’s it called? “The Way Through the Woods: On Mushrooms and Mourning,” by a woman whose husband died, and she took up amateur mycology, she took up mushrooming, right, going mushrooming, you know, to kind of distract her from the grief and whatever, and it’s a beautiful book.

But this whole section in it, one of the things that mycologists do when they’re trying to ID a mushroom is first, they pass it around, they slice it and they smell it. Everyone smells it, and the same thing—it was exactly what you had talked about: How do we put this into words? There’s no language for it.

Ken: Well, it’s interesting that you say that because I’ve read that, and I haven’t experienced it myself, but some mushrooms smell like chocolate. You think of that sort of musty, earthy smell of the mushrooms that you buy at the store, which is good, too, a mossy, earthy smell. But I’ve read that some mushrooms we even know have fragrances. I should check that out. Good thing to think about.

Margaret: Yes. So it was like, I thought, “Oh, Ken will love this.” I’ll send you a copy of the book. But it’s like, Ken will love this because it’s just the same kind of you said, “I want to write about this, I want to explore this.” And then it was: Where are the words? What are the words to use for this? So you did have to, because it’s a book, you did have to come up with a language for it. So what did you do?

Ken: Well I’ve found that mostly I had to use analogies. With colors, there’s so many words for colors, like cerise and stuff. And there’s even words that come from plants, like cherry, and all sorts of things. But for fragrance I can say sour maybe, or tart, or pungent, but then you have to say like coconut or something that people would know. Vanilla-scented or smells like yellow cake when you were a kid, something like that. And there are flowers that smell like yellow cake when you were a kid.

Margaret: [Laughter.] So, you tried to get as descriptive to conjure something that people could then sense the smell, even just reading about it, by the language you chose, right?

Ken: And it’s somewhat subjective, different senses of smells smell a little differently. But I would, in the book, I have a lot of things about how smell works and things like that. And then there’s an encyclopedia of well over a hundred plants and flowers and parts of plants. It’s herbs, too. And I try to describe them, and I have the primary scent within categories, and we could talk about that, too. And then the secondary scents, because some things like hyacinths, some people don’t like the smell of hyacinths, but I started a list of what it smells like and, “Oh there’s a little bit of this and that and a little bit of that and this,” and it’s probably got six different things that I can pick up in there.

Margaret: Now when you say “pick up,” that’s not just by taking one big whiff, is it?

Ken: No, I can’t say aneth … O.K., help me out here.

Margaret: Anesthetize, like from anesthesia, anesthetizes.

Ken: You become accustomed to smell.

Margaret: Yes, yes, yes.

Ken: I don’t know. I read it when I was doing research that they, I don’t know if they still do this, I’ve never experienced it. But they used to have bowls of coffee beans, you know like at Macy’s and stuff, in department stores. So when you went through the perfume area, and they would reset your smell receptors with coffee beans, as sort of the baseline. But as I, as I was doing the research, I found out that perfumers use the inside of their elbow. They just smell the crook of their elbow, because you’re accustomed to your own smell, and it resets your smell receptors.

Margaret: O.K. All right, good. So, yes, so little sniffs, we should sort of sip it, sip the smell, right? Not drink it down all at once. Now plants: So before we leave that subject of the language you came up with, how many categories, sort of these overall categories?

Ken: There are 12 categories of fragrance. They were kind of based on what perfumers use and what I thought about.

Margaret: So give some examples.

Ken: Well, they’re alphabetical. And the first one is animalic, which are things that have sort of animals smells, like skunk cabbage [Symplocarpus foetidus, above], which is kind of skunky. And I don’t know if you’ve ever experienced ginkgo fruits.

Margaret: Oh, please.

Ken: [Laughter.] Or, well did you ever cut fritillaria and put them in a vase?

Margaret: Yes, yes.

Ken: Yes, that’s kind of foxy.

Margaret: So animalic, O.K. Animal-like-ish.

Ken: Then I have balsamic-resinous, and it’s not like the vinegar; the vinegar is like it. So it’s resins that are not conifers, not piney resins, and that goes way back to the frankincense and myrrh. But things that are balsamic-resinous includes caramel and vanilla.

And then I have floral-sweet, which is really where everything else goes when things are like mock orange or primroses. And you really do want to say sweet. I tried not to say sweet.

Margaret: Yes, it’s too hard.

Ken: Because white sugar doesn’t smell like anything.

Margaret: Right.

Ken: But I have a floral-sweet section for all those other things like daylilies, too, they’re floral, and they’re sweet. They don’t fit into animalic, and they don’t fit into fruity, exactly.

Then I have forest, which is the coniferous scents, but it goes from rosemary to pine all the way down to those mushrooms on the earth.

And fruity, which are things that actually may be fruits, like a citrus fruits, or citrus leaves have a different smell. Freesia is kind of fruity. Pineapple sage, of course, got its name [from its scent]. Bearded iris are often grape soda-smelling, tall bearded iris. Then I have the heavy ones, like I know one of your favorites: the Oriental lily [below]. [Laughter.]

Margaret: Oh, please, please get me away from those. That’s too much for me. I can’t, it’s too intense for me. [Ken’s dog barks in distance.] I heard one of the children’s voices in the background.

Ken: Pippa. Come on.

Margaret: Pippa, hello, Pippa. So O.K., so heavy stuff, right? And I’m not crazy about that. And what’s the next category?

Ken: Well, Oriental lily is one of your favorites. And I was just thinking, that’s one of the ones I have. My list has burned sugar, indole—we could talk about that—honey, vanilla, baby powder, anise, grapefruit, and clove. That’s what I pick up in that Oriental lily. And then at 5 o’clock it gets stronger, which is terrible for you.

Herbal green, things like anise, and it’s just up, and well licorice-smelling things. Hay-scented fern, oregano, honey. A lot of things smell like honey, like sweet alyssum, that’s like super honey.

Indolic, and indole is a compound, a molecular compound, and that compound is in a lot of flower smells, and it’s kind of like mothballs. And that sounds terrible, but if you smell something sweet and nice, if you keeps sniffing like that, you’ll pick up that mothball in the background, and that’s indole.

Then there’s the things that are medicinal smelling like artemisia and eucalyptus and even salvia.

Margaret: I love those. Those are the ones I love, yes.

Ken: Oh really?

Margaret: Yes, that’s my thing. Yes.

Ken: And then there’s roses, of course, and gosh, I could have done, you know, another three books on roses alone, but roses. And I have old roses and modern roses and what they smell like. And the last category is spice.

Margaret: Spice.

Ken: So I put things in there like Dianthus that smell like, well they smelled like clove because they have eugenol, which is the same spice that’s in cloves, same compound. And one of your favorite plants. Geranium macrorrhizum, I put that in spice.

Margaret: Yes. I love the things with a spicy or the medicinal—the pungent foliage especially. I’m more a foliage person than a flower person in terms of the scents, I like them. So there’s this diversity of scents, and then you have sort of sub-scents within each one. If we sipped the fragrance a little bit at a time, we may smell five different elements in the first impression and then other impressions. But plants didn’t come up with fragrance so that we could enjoy it, or loathe it in the case of some. [Laughter.]

Ken: No it’s a coincidence.

Margaret: So, this is not for us, right? I mean-

Ken: No, it’s for the pollinator. Well, you know, I was going to say it’s for the pollinators. And in the case of the nice-smelling flowers, well, on all the flowers, really, it’s for pollinators. Something that smells like dead meat is for the flies to come and pollinate it.

Margaret: Right, different pollinators, right.

Ken: But often with the, I was going to say we just with the herbs that have those smells, medicinal smells that you like, predators don’t tend to like those.

Margaret: Yes, it’s anti-predation. Right. So, and some plants are, you mentioned one just a minute ago, are scented or more strongly scented in the evening. And that’s also not for us to put by our patio, although we could if we sit out on our patio in the evening. But that’s not why it evolved that way. It’s, another strategy, right. For nighttime pollinators for instance, like maybe it’s moth-pollinated, right.

Ken: Moth-pollinated, or bats sometimes right. For the right plants. And a lot of those plants are white because they reflect the moonlight to attract them by sight as well as by fragrance.

Margaret: Right. So in doing this book, you did some kind of experiments and stuff like you, you did some sort of crafty things and you kind of went on a lot of adventures, didn’t you?

Ken: Well, I don’t like perfume. I don’t like air fresheners. I like the natural things, but I thought can I capture some of this? And I read a lot about how different perfume, well, essential oils are extracted. Sometimes it’s just squeezing a lemon rind and everyone’s done that, and the oil comes out and that’s your lemon fragrance.

Then there’s some flowers where they use solvents, chemical solvents. Sometimes CO2 is used as a safe chemicals solvent. Flavors tend to have water as a solvent, but fragrances use oil as a solvent, often. People use to steep fragrant things in oil, and of course we make vinegars with herbs. Burning—like incense—that’s another way of getting or capturing a scent. Distillation is often used for things that can stand up to heat.

But there’s something that used to be done with delicate flowers, and it’s called enfleurage, and it was done in the 1700s, and it’s still occasionally done.

And that uses… well, they used to use animal fat, like lard or tallow, and they’d spread animal fat in a thin layer on sheets of glass in a frame. And then they’d press petals of a rose or tuberose or jasmine into this fat, then lift them off and replace them and do that for two weeks straight, and then scrape off the oil. And they would either use it that way, or they would use alcohol to remove the essential oils from the fat.

So I wasn’t about to do that, and I don’t have enough flower petals. But I spread… I melted some vegetable shortening in a pan and pressed the pedals of my favorite Rose, old rose in the garden, which is called ‘Petite de Hollande’ rose from 1720 [below]—it’s an amazing fragrance, very strong. And I press them into the shortening, and cover that with another pan. And put it in dark place for 24 hours, lifted off the pan, pulled out the petals, and I had the fragrance of my favorite rose from early June to January.

Margaret: In the residual oil.

Ken: Right in the jar. And then it kind of faded, but I had it in January.

Margaret: All right. So you kind of, yes, that’s kind of fun. Is that preserving… can we preserve the fragrance, right? So into the garden you have fragrant plants, you have a lot of things that you grow indoors as well. So indoors and out. I mean are there plants that in doing this book you realized right away, “I’ve got to showcase this plant or that plant or there’s some favorites or I couldn’t live without?” Because you said you feel like when you go out into somewhere, and you meet a plant, and you put your nose to the flower, if it’s doesn’t have a scent, it’s lacking. So what are, are there some Ken’s favorites in this book showcased? A million?

Ken: A million? I like Jasminum sambac. Do you know what that is?

Margaret: Yes. Jasminum sambac.

Ken: The Arabian jasmine—I love that. And jasmine is not so easy to grow in the house, but that one is. It’s not the prettiest plant, but it blooms. Tiny flowers that can fill a room, one flower. Outdoors I am wild about Calycanthus.

Margaret: Yes. And this is a plant that I’m seeing, like our friends at Broke Arrow Nursery and some other choice nurseries. I’m seeing it more. And there are more selections for flower color, size of the shrub.

Ken: But they don’t all smell.

Margaret: No, no. What’s the common name for it? Is it like Carolina allspice?

Ken: Carolina allspice.

Margaret: Allspice. Yes. Calycanthus floridus [below] is a native shrub. I don’t remember to what regions of the country specifically.

Ken: It’s sort of Southern, but there’s a California species as well [C. occidentalis].

Margaret: Yes. And there’s, some of them have a dark reddish flower, and I think some have, do some have white? Did I make that up?

Ken: There’s a white one called ‘Venus.’ They’re mostly, and you’ll remember this because this happened in your lifetime with people you know, but Dan Hinkley found Calycanthus, well, it was called Sinocalycanthus because they thought it was a different genus, but it turns out that it wasn’t. So it’s Calycanthus chinensis, which has beautiful flowers but they are not fragrant. But that contributed to the hybrids that we now see—the big flowers, the white flowers. And I think, and I hope they’re not listening, but I think my favorite is ‘Athens,’ which has chartreuse flowers, and they smell like green apples and honeydew melon. It blooms for a very long time, late spring-

Margaret: But it’s not at the peak when you’ve got so much going on in the garden in spring that you can barely keep track. It kind of stretches the fragrance toward the summer, I think, doesn’t it?

Ken: And the fragrance changes over the age of the flower. It smells a little bit, and it attracts a beetle that climbs inside the flower that while it’s still closed and then it can’t get out. And then for one day it doesn’t smell, and then it opens up, and it smells again to attract the next beetle to deliver the pollen. All these things are just amazing. And if the humidity’s right at 5 o’clock in the afternoon, I can smell that Calycanthus from about 40 feet away.

Margaret: Yes, that’s right.

Ken: And it’s a wonderful smell. But everybody describes that plant differently. Those red ones, I think they’re whiskey barrel, or lacquer thinner.

Margaret: Oh, funny.

Ken: That’s a game I play when guests come.

Margaret: “What do things smell like to you?” Yes.

Ken: And they say bubble gum, fresh strawberry.

Margaret: Yes, yes. And so many different things that I’m, I mean the, the fragrance… like for instance, hosta, I mean there are some hostas, even, among familiar plants. There’s a lot of breeding going on in hostas I think to accentuate the genetics that include fragrance, yes?

Ken: Seems like there’s just one species of hosta that smells, which is Hosta plantaginea, but now they’ve hybridized, there’s dozens, and if you find a hosta that has plantaginea in its ancestry, it will be fragrant. And there’s a list in the book of about 20 fragrant hostas, but there is more coming out all the time, ‘Guacamole’-

Margaret: Are they often white flowers? Plantaginea is white I think.

Ken: It would be, right. And there’s plantaginea ‘Grandiflora,’ I know you know those at Wave Hill, they’re so beautiful. Those are very late. They bloom in August. But some of them do have the little bit of the purple-ish in them, but the flowers are almost always open. You know how some hosta flowers never seem to open, but the plantaginea open and the pollinators loved them, and I love them, too.

Margaret: And even daylilies.

Ken: Daylilies to me that almost all the older daylilies smell, and most of the funky hybrids with their piecrust edges don’t seem to smell. Although I have a double one, yellow double one, that does smell wonderful, and from far away, too. But the yellows to me seem to not only smell best, they taste best.

Margaret: [Laughter.] You like to eat them?

Ken: I do. I eat them in salads. The Chinese people, that’s what they say. You know, the Chinese stir-fry the buds, but I can’t sacrifice the flowers. So I pick the flowers, especially old ones like ‘Hyperion’, a yellow one that smells so wonderful and I just shred the pedals and put it in the salad, and it’s beautiful and tastes delicious.

Margaret: I was surprised to see Echinacea, some of them are in the spice section [above]. I think of the chapter about spice, yes?

Ken: So weird, you know, purple coneflower—I never thought they smelled, but when they started having all these different ones, and now you know, there’s so many different ones. All these colors, which are they’re Echinacea purpurea with Echinacea…, it has the name of not being purple.

Margaret: Yes, I don’t remember what it’s called, either, but I’ll remember after we hang up.

Ken: I know, I was going to say pallida, and it’s not that; it’s like confusa or something. It’s not that, either. But those colorful ones, they smelled to me like something I grew up with, Constant Comment tea. [Update: Ken remembered later, as promised, that he was thinking of Echinacea paradoxa.]

Margaret: Yes, yes.

Ken: They have a kind of cinnamon, clove and orange scent and often, hay, either, hay going to orange and clove. And a lot of them smell. And now I even see there’s one, there’s a couple that have fragrance in their names, in their hybrid names.

Margaret: Yes, because I never even thought, frankly, to put my nose to them and see if they smelled, do you know what I mean? I don’t think of it as like, “Oh, Echinacea, coneflower, it’s a scented flower.” I never thought about that.

Ken: And they didn’t use to be.

Margaret: No, no, no, no. So, well there’s so many different things to talk about in the book, “The Scentual Garden.” I was thinking that maybe during catalog-shopping season, Ken, which begins in December-ish, say, and goes into the new year, I thought it’d be kind of fun if you would be willing to do another visit to the show. I thought it’d be fun to shop the catalogs together with a nose to scent, as opposed to just a pretty pictures. [Irises, above, from the new book.]

Ken: [Laughter.] A nod to nose to scent.

Margaret: But don’t you think that could be fun?

Ken: I do. I do that.

Margaret: O.K., so let’s plan to have a date to do that, O.K.? And congratulations. Number 20, book number 20, good for you. We’ll have a giveaway as I said, and I’ll talk to you soon.

(Photos from “The Scentual Garden,” including flatbed scanner collages by Ellen Hoverkamp.)

enter to win ‘the scentual garden’

I’LL BUY A COPY of Ken Druse’s 20th book, “The Scentual Garden: Exploring the World of Botanical Fragrance,”  for one lucky reader. All you have to do to enter is answer this question in the comment box below:

What’s your favorite garden fragrance, or type of fragrance? (As I said, I like spicy-scented leaves the best, more than super-sweet smells.)

No answer, or feeling  shy? Just say something like “count me in,” and I will, but a reply is even better. I’ll pick a random winner after entries close at midnight Tuesday, October 22, 2019. Good luck to all.

prefer the podcast version of the show?

MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its 10th year in March 2019. 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 October 14, 2019 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).