WHO AMONG US doesn’t have at least one Urgent Garden Question? This month on my public radio show and podcast, Ken Druse and I answered a diverse list:

About fighting the parasitic vining plant called dodder (above, sniffing out its preferred host). About why sometimes not all nursery plants bought at the same time perform the same once planted in our gardens. About some different Nicotiana, beyond the usual suspects. About when and how to save seed from Eucomis, the pineapple lily, to propagate more bulbs. And about selecting “improved” plants that show up in our own gardens to perhaps save seed from, to create our own strain.

You all know Ken Druse, my longtime friend and fellow garden writer, author of “The New Shade Garden,” and “Natural Companions,” and “Making More Plants” among other great books. You can enter to win a copy of “Making More Plants” in the comments at the very bottom of the page.

Read along as you listen to the Aug. 27, 2018 edition of my public-radio show and podcast using the player below. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).

All Ken’s and my past Q&A shows and transcripts are at this link.

selecting a better ‘strain’
of a cherished plant in your garden

Q. Ken Druse and I have been asking ours to each other for decades and today we’re back to answer some more of yours, as we do each month on the show.

A. [Laughter.] Decades?

Q. Sorry, O.K. Sorry, I’m sorry.

A. Decades! Uh-huh.

Q. Yes, well, when did you write “The Natural Shade Garden” and “The Natural Garden?” Hello!

A. Well, let’s move on from that, please.

Q. O.K., goodbye. [Laughter.]

A. O.K., yes. Questions?

Q. Yes.

A. Oh yes, right.

Q. So actually before we even do listener questions, I have a question for you because I was looking something up in “Making More Plants,” your propagation book, the other day and it got me wondering. Are you doing any sort of propagation-related mad science over there in your garden these days because you haven’t told me about any of … Normally, you have some wacky projects going on.

A. Uh, no thank you. Moving along. [Laughter.]

Q. O.K.

A. I always have something going on, you’re right.

Q. Boy, I’m really striking out with you today.

A. Are you talking about making my own strain or something?

Q. Yes! I mean, I thought that you must be because you’ve told me sometimes, but then I haven’t had any follow-up. So tell me about that.

A. Oh, wacky is right. Let’s see. Well, you know, people talk about strains of plants, and heirlooms, and things like that. When you talk about an heirloom, which is a strain, they don’t say strains, it’s usually a version of a plant that’s propagated or grown in isolation so that it retains the characteristics. If you don’t grow it in isolation, then it ends up either reverting to the original species or it gets mixed up with some other strain, and then you lose it. That’s how people retain the characteristics of an heirloom tomato, for example.

Q. Yes. Like instead of allowing genetic drift to happen by neglect, by not caring for it and keeping it as they say, “True to type,” to what it’s supposed to be like, it can drift away from that. Yes. So nobody’s minding the store and the thing drifts, but you’re talking about what then?

A. Well, I guess the simplest version of it would be the double poppies that I have. I have these orange poppies, little ones, and they’re single ones and occasionally I get a double. For about three years or so, I was pulling out all the single ones and now all of mine are double, so I’ve-

Q. So this is selection; you’re kind of selecting.

A. Right. And it’s a strain, or I could say it’s an heirloom except it’s not that old. But I have another plant in the garden which is a kind of Verbascum and gee, what’s the … mullein. So it’s a kind of mullein, but unlike the road-side mullein that has hairy gray leaves and one flower spike, mine has multiple flower spikes and it blooms for about six weeks. [Above, the Verbascum in Ken’s garden.]

Q. Wow!

A. Which is a long time for a biennial. I was going to say, “perennial.”

Q. How tall? How tall is this thing?

A. It’s about 5′ tall.

Q. Wow!

A. And it has about between four and six arms. And each of the arms, like a candelabra, has more arms coming off it, so it’s really just covered with flowers.

I know where this came from because I originally had a species, which was Verbascum undulatum, which has a wavy leaf. I was also growing at the same time a hybrid called ‘Harkness Hybrid’ from England. It croaked, actually; I had it for about one year. But what came up in the garden were some really interesting verbascum. I started to save those and anything that didn’t look like them, I would pull out. They have a wavy leaf and it’s green, it’s not very hairy, and that became the strain.

Now every year, luckily, I get between two and 12 plants of this verbascum strain. I’ve shared it with some people and it seems to be kind of true, and that’s my verbascum strain.

Q. So it’s an annual poppy, the orange one with the little double flowers, you’re saying?

A. Yes.

Q. Yes. Huh.

A. I’m trying to remember what the species name is.

Q. Yes. Is it like the California poppy-ish?

A. No. And I keep wanting to say alpine, but that’s not right, either.

Q. O.K., well, we’ll just go look it up afterwards before we do the transcript. [It’s Papaver rupifragum, the Spanish poppy.]

So you’re selecting, you’re noticing things that are a little different and you’re saying, “Oh, I kind of like that,” and then you’re guiding it by, as you said, you’re roguing out the single orange poppies and only letting the doubles set seed for next year.

A. Right. And pretty much now after about four or five years, they’re all double.

Q. Have you ever done with this with woody plants in any way? I mean, it’s not quite the same thing, but have you ever noticed something on a woody plant that was … Do you know what I mean? Or is it just with annuals?

A. Yes, I know what you mean. Not really, but I have with herbaceous perennials. And actually, a perennial that you love, which is Geranium macrorrhizum, that groundcover, I saw one that had white variegation.

Q. Oh!

A. Just kind of little lines of white. Now, that could be a disease or it could be something else-

Q. A virus! [laughter.]

A. So what you want to find out, yes. So I have propagated that and it also retains the white. It’s actually a variegated white-on-green Geranium macrorrhizum. Now I have it in three places and that seems to be, we’d say, “stable.” So it’s probably not just an aberration of funny soil or something going else on.

You know, you seem something like that in the garden, you think, “I’m going to be a millionaire. This is it. Everyone’s going to want this plant. They’re all going to give me royalties.”

Q. The big bucks in horticulture. Woo-hoo!

A. And frankly, that doesn’t really happen. [Laughter.]

Q. No.

A. Or very rarely.

Q. You’re reminding me. The Broken Arrow Nursery guys, it was either Andy Brand, who no longer works there but did for many years, or Adam-

A. Wheeler.

Q. Yes, Adam Wheeler, who came to the garden as they do to do my plant sales at Open Days. One of them pointed out, walking along the path, that some of my European ginger, shiny-leafed, kidney-shaped leaf groundcover, Asarum europaeum, that one plant had kind of mottled leaves.

It could have been a virus, it could have been, as you said, something in the soil, or it could have been stable. He said, “Oh, let’s mark that. Let’s put a stake there and say to ourselves, ‘Let’s look at that next year.'”

So I guess they’re always on the lookout because they love unusual plants and they’re always looking to introduce something new or whatever. So they’re looking for, as you say, stable, ornamental features that are different.

A. Well, sometimes that happens and sometimes that actually ends up being something valuable, although very rarely. [Laughter.]

Q. Right, right.

A. And so the things that people find are not usually accidental; they’re kind of intentional, the ones that really make money. But look in your own garden–I’m talking to the listeners–and you might find something. It may not be the thing that gives you the new house in the Hamptons, but it might be something that you want to perpetuate. Discover if it is stable and if you maybe develop your own strain.

Q. Yes, kind of fun. All right, so now onto the promised reader/listener questions. Sorry readers/listeners, I didn’t mean to delay but I meant to ask you that, Ken, last time we spoke.

the parasitic plant called dodder

Q. I have a question from Linda on dodder and she says-

A. Ugh!

Q. I know. She says, “The native and parasitic plant dodder has shown up on my landscape. I’ve been working all summer to get rid of it.” And she had yet to read about anyone else that has experienced it, so she welcomes any information.

Now, have you experienced dodder? First, we should probably explain—tell us what it looks like. [Above, dodder engulfing a host plant in a Wikimedia photo by Fritz Geller-Grimm.]

A. Well, it’s related to morning glories, and it is orange, and it’s stringy, and it sprouts from a seed, and then it has a few days to find a host, just by being a vine. If it doesn’t find a host within a couple of days, it’s used up all the nutrition that’s in the seed and it croaks. But it usually does find a host, and then it climbs up the host, and it sticks suckers into the host and lives off it as a parasite.

Q. Yes, so it’s a parasitic thing.

A. Yes.

Q. And those little holdfasts that then suck the life out of the host plant, I think they’re haustoria. Really, these specialized structures that let it do that. And dodder doesn’t have any real roots or real leaves of its own. It does have flowers, like you said, and it does make seeds. What’s really cool is that there’s 200 kinds around the world, like different species.

A. Oh really?

Q. They’re all in the same genus. I guess it’s pronounced Cuscuta. As you said, it’s in the Convolvulaceae, the morning glory family. So yes, we have some native species in the U..S in different areas, but now there’s a Japanese invasive species. So as if it weren’t bad enough to have native dodders strangling and sucking the life out of certain host plants, some agricultural areas, especially in California and some other places, are being besieged by a Japanese outbreak species as well. Crazy.

A. So what do you do about it?

Q. It looks like this yellow or orangey string that’s twining, twining, twining. Right?

A. Right.

Q. Right, O.K. Well, I mean, let’s talk about in the garden setting because in the agricultural setting, it’s a whole other nightmare. But what have you done? You said you’ve had it.

A. Well, and I do. Usually almost every year I see a little tiny bit of it and I get it right away. Some years, after the flood actually, it was everywhere.

But now I only see a little bit and I go to the host, and I take every bit of the dodder that I possibly can, and I put it in a paper bag that goes in the trash, not on the compost. It’s very brittle so it breaks while you’re trying to collect it into pieces. So you’ve got to get all of it.

It seems to like the native wild impatiens, which is something that I can sacrifice. So if I have to, I’ll take out that whole plant with the dodder and just get rid of it.

Q. Yes. And the different species of dodder are host-specific; they have different preferred hosts. So again, there are ones that are agricultural pests of alfalfa, or carrots, or onions, or potatoes. There’s one that likes cranberries as its host. All kinds of different things. Even ones that seek particular weeds, things we consider weed species, and parasitize that. They’re specific, they have specific relationships with other species of plants. Very interesting.

And the seeds that it creates can last, I read somewhere, 60 years in the soil. So the thing most important of all is not to let it go to flower, these tiny little flowers, right?

A. Yes, I was going to say.

Q. You can track those around from place to place in the garden or a farm field on your shoes, on the tires of a wheelbarrow, or a tractor, or whatever. So it’s this not spreading it inadvertently, this hidden thing.

Some people say you even should take off the–rather than just try to pull the dodder off the host plant–remove the parts of the plant that have been entwined and hooked into, so to speak, because you have may be leaving, inadvertently, some behind.

A. Right, right.

Q. And then of course, a lot of people use chemicals and whatever. In a garden setting, we’re not going to do that. I had it one year and I never had it again. I did what you said, so I think it’s vigilance and over and over and over and over, not letting it flower, etc.

A. We’re lucky that it’s bright orange, you know?

Q. Right.

A. Because you can see it. Imagine if it was green! Oh my goodness.

Q. Yes, with the transcript, there’s some pretty interesting research about it and so forth up to … I mean, they’re even trying to sequence the genome of it at the moment. There’s kind of interesting stuff, I mean, in that it’s a parasite and so forth. I’ll give some good links with the transcript.

• About dodder, from the University of California IPM website
• About dodder, from Missouri Botanical Garden

when ‘identical’ transplants each behaves differently

Q. But Phlomis—Ann had a question about phlomis, a mint relative perennial, that’s a mint relative. She says she listens every week from out in Olympia, Washington, finally writing in with a question of her own. She planted four Phlomis russeliana, young plants, young, healthy plants last fall.

Only two of the four bloomed this spring and she says, “What’s up with that? Why would the same plant,” they look the same in the same cultural conditions, “act differently?”

And then she notes that the conditions that she’s offering are not ideal for the plant. It’s a kind of clayey soil that drains less well than the plant might want in its native habitat. So what do you think? [Above, P. russeliana photo by JH Mora, from Wikimedia.]

A. I could ask her 50 questions.

Q. Or? [Laughter.]

A. Or. I love phlomis.

Q. Me too.

A. And it’s beautiful and I wish I could grow it. The problem for me is it’s just too humid here because that’s a plant that really wants great air circulation, it wants the Mediterranean, it wants to be dry and have great drainage. And she’s challenging it maybe by not giving it great drainage. But I think Olympia, Washington kind of has dry summers, which is what it would like.

But hearing you describe all that, my first guess is just that two of them just aren’t mature enough.

Q. Yes. And I think sometimes we see plants in the nursery and it looks like there might be a flat of 36 of something and they all look “identical.” But maybe the roots beneath the soil surface in those pots, maybe half of them are a little more or less developed, or the division that they came from was a little more or less … don’t you think?

A. Yes. So get in touch with us next year.

Q. Yes, I want to know. I think they’re going to do O.K. I don’t think the clay soil is ideal, probably.

A. No, but if they’re alive and they’re pretty much together in the same place. And it depends on what was the winter like? Blah, blah, blah. If they had a dry winter, they would like that, really. They don’t want to have wet feet in the winter.

Q. Yes. But I do think the products, these are not widgets, as we always say about plants. They’re not widgets, they’re not uniform, so we have to expect some–just like people or animals will settle in more or less quickly, right? Give them a chance.

A. Right.

how to grow eucomis from seed

Q. We had a question from a Dutch gardener. He says he’s from Holland and he says his English is not that good, but it sounded pretty good to me. He grows Eucomis. Doesn’t say the species, but they’re flowering really well. They’re in the ground in the garden. He wants to collect the seed to create his own bulbs eventually. His question is, “What stage of the flower development, what would the flower look like when the seeds are ready to collect?”

A. I can’t believe you’re asking me this. [Laughter.] [Above, pots of eucomis at Ken’s garden.]

Q. Why?

A. Because I’m such a sucker. You were asking me about experiments-

Q. Uh-oh.

A. And now that you’re saying that, I’m remembering, that Eucomis, which is the pineapple lily, has these beautiful flowers right at this time of year. It’s August for me. The flower spikes come up and then they have these star flowers on this fleshy, succulent stem. And then sometimes, very often, fruits form.

The fruits are about 5/8″ long and kind of around, even though they’re not round. They’re little pointy things. Inside those fruits are shiny black seeds. The black seeds call to me from across the garden, “Collect us, propagate us.”

So I cut some of those stems and I carefully put them under the sun porch so they wouldn’t disappear, which sometimes seeds do especially because these fruits will turn dry like pods. But the seeds are ripe before they turn papery and I didn’t want them to fall out, so I put them in a place I thought they were O.K.

I collected some and I thought I’m going to try to sow them right away, and they actually came up. That was last year, and I’m thinking these are going to take seven years to bloom. I’m really sure they will. But I happened to notice–and we had a very cold winter–I happened to notice something growing in the gravel under the place where I had them.

Q. Really?

A. Everything likes to grow in gravel, it’s just perfect.

Q. I know, I know.

A. And the whole area there is crushed rock. I thought, “What are these?” I realized they’re eucomis seedlings! They went through our very cold winter, although it’s close to the house. They probably liked having a chilling period. I think if I sowed them again, I might give them a chilling period. But I sowed them and they came up under lights. We’ll see what happens, but I-

Q. So the stage of the ripeness … It’s just before it gets so papery that they might disperse, is that when you’re saying would be ideal?

A. Yes, they start kind of a color. Depends on which one, on the white ones, they’re kind of green pods; on the red ones they’re kind of reddish-colored. They start to get pale. They lose their color. I cut them before they got dry because I thought they would get papery and then the seeds would fall out.

Q. And that’s the trick with saving seed a lot of times is sometimes it disperses itself if you don’t get it a little early. Right?

A. Right. And it was a little early, exactly. But I should have put it in a tray instead of on the table. [Laughter.] Because those little round, rolling seeds seem to have fallen in to the gravel–some of them–and I guess I don’t know. What should I do? Dig them up or late them grow there? I’ll think about it.

Q. I don’t know, I don’t know. That’s interesting. I’ve never had them self-sow.

A. Try gravel! And you know, we were minus-10 here and eucomis aren’t that hardy!

Q. I know. No, it’s funny. I think they’re like a 7 or maybe 6b-ish thing.

A. Yes, but I think the seeds are hardier, which is the case with a lot of things like that.

growing nicotiana mutabliis

Q. IYou know, I said in the introduction that you and I have been asking each other questions for a long time. You took exception with the length of time I said, but the other day you asked me a question and I thought, “Well, maybe other people might want to know.” But you’re going to have to ask me again. Do you remember what you asked me about?

A. Are you talking about your Nicotiana?

Q. Yes. Yes, just as an example of the kind of stuff you and I—because we’re always emailing back and forth-

A. Well, we were talking about that, right.

Q. Saying like, “Do you know this? Do you know that?” It’s a true thing, I wasn’t making that up in the introduction when I said that. You and I have been asking each other Urgent Garden Questions for decades. I know you hate that, but a long time.

A. Oh, yes. We could do hours on that.

But I guess it was probably last time I was at your place, which again, around this time of the year, and you had a huge–I’d call it a meadow [laughter]–next to the house of Nicotiana. Most of them looked like mutabilis, which is the nicotiana that the flowers change color. It’s pretty tall.

I never was there at night and I never actually sampled whether it was fragrant, so I wondered if Nicotiana mutabilis, the beautiful color-changing nicotiana, which I’ve never grown actually, whether it smelled?

Q. Yes, this is my favorite nicotiana. And when you say, “meadow,” it’s kind of this … it’s a lot of plants altogether in a group. It’s not like actually out in a field somewhere. It’s adjacent to the house and the reason being completely selfish. The nicotianas for me, the flowering tobaccos for me, flower in late summer so from late July, mid- to late July, through the hard frost.

That’s when the one species of hummingbird that we have in our area, the ruby-throated, is coming through in large numbers, moving the populations that were farther north, and they love to stop at the garden. They love to stop anywhere where they can find nectar, yes?

So I put these big masses– I let them self-sow–of nicotiana near to the window so I can sit there and just be delighted by these crazy groups of hummingbirds visiting me. That’s what the “meadow” is for, and so I have a few of these plantings, again self-sown plantings, naturalized, near where I can see them.

So mutabilis is a really tall one. I mean, it’s probably as tall, almost, as I am, and very statuesque, like a big candelabra kind of thing. The flowers start out white and I was just looking at one today actually, and then they gradually age. Each flower, each ages to pale pink and then even rose. Sometimes you have three or four shades from white to rose on one big plant. I don’t think there’s any fragrance. What’s the big white one called?

A. Alata?

Q. Yes. There are a number of nicotianas and the one that has the really tubular flowers-

A. The sylvestris.

Q. Yes, sylvestris. Those, I believe, have scent, but this does not seem to have a scent and I’ve even been outside in the evening, because I’m into moths also. I have never noted any fragrance whatsoever. So that said, we’ve run out of time.

A. You’re going to send me some seed?

Q. Yes, I should try. Now, that’s one that will disperse the seed whenever it damn well pleases on a moment’s notice. So I’ll probably have to put a bag over some of those. You know what I mean? Put a little paper bag with a twisty tie or something so that the seed falls into a bag for you, but yes.

A. Thank you.

Q. Yes, yes. All right, well thank you, Ken, for some help with the Urgent Garden Questions. I’m sure I’ll be emailing you something I need to know any minute now, so be on the lookout. [Laughter.]

A. Yes, Papaver rupifragum. That’s what you need to know.

Q. Oh, O.K.

A. Spanish poppy.

enter to win ken’s ‘making more plants’ book

I’LL BUY A COPY of Ken Druse’s propagation book, “Making More Plants,” for one lucky reader. All you have to do to enter is answer this question in the comments box at the very bottom of the page:

Have you ever saved seed of an “improved” version or strain of some plant in your garden–like Ken does with his double orange poppies–or saved seed of any other thing you especially cherish (like he did of the Eucomis or pineapple lilies?

No answer, or feeling shy? Just say something like “count me in” and I will, but an answer is even better. I’ll select a random winner after entries close at midnight Tuesday, September 2, 2018. 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 ninth year in March 2018. 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 Aug. 27, 2018 show using the player near the top of this transcript. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).