TACKLING CANADA THISTLE, and the ethics of herbicide use. Reblooming amaryllis. Moss in the lawn or garden beds. Pesky squirrels. Propagating philodendron, and fragrant violets. Those are among the questions that have been asked lately, and my friend Ken Druse of KenDruse.com helped me answer them in the latest edition of our Urgent Garden Question shows.
We’ve got lots of questions coming via the contact form and on Facebook all the time. Thank you, and keep it up everyone.
Read along as you listen to the April 9, 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).
april q&a with ken druse
Q. Hello, Ken. I have to say I was surprised not to get any amaryllis questions this whole last winter at all. Usually I get, you know, “How do I re-bloom it from last year’s bulbs,” whatever. So that was one that didn’t show up; that’s one of my usuals.
A. Why? [Laughter.]
Q. Why is it one of my usuals, or why didn’t it show up?
A. No, no. I’m surprised, frankly.
Q. Yes. Me, too.
A. That’s always the question. And I have to admit I’ve had amaryllis for years unsuccessfully, and they have these strappy leaves, and they look terrible. And maybe they get mealybug, maybe they don’t. And they never bloom again. But last year I was determined to get my amaryllis, at least one, to bloom again, and I did.
Q. Oh, O.K.. And you did it by?
A. Well, I kept it in a really good place, lots of bright light through the summer, and watered it and fed it a little bit with a balanced organic fertilizer, kind of like a 5-5-5 or something like that. And then in September I moved it, still outside, but to a spot where it wouldn’t get any rain. And it’s not overpotted; it’s in a terra cotta pot that’s just a little bit bigger than the bulb. And I let the leaves stay on, and they started to not look so good. And then they got a little yellow. And I just cut off the yellow leaves. I didn’t cut it back like when you buy it.
A. Then I brought it inside, and in January, it sent up its flower spike. And I’m going to do it to all the bulbs next year for sure.
Q. So just let me be clear. So you moved it, and then eventually you moved it to indoors, right?
A. Right. Sorry.
Q. O.K., and you didn’t water for how long? How long were you resting the bulb so to speak?
A. Well I started resting it really-
A. Middle of August, I stopped watering it.
A. And then I moved it just so it wouldn’t get any rain. And then I brought it in before the killing frost, which is mid-October or so. And then I put it in a very bright sunny window, but didn’t water it. I didn’t water it at all until it started showing that flower spike.
A. I didn’t repot it. I kept it in the same pot.
Q. One of the things I found is that I can re-bloom them after the first year of them skipping bloom. In other words, they’re on somebody else’s schedule, like from the grower, the first year, on the anniversary of when I got them, right? And I have trouble that year, getting them used to my system. But if I stick to it, I can get them to do it after that. And maybe I’m associating or conflating thoughts, but I sort of felt like I don’t have the same conditions as where they were used to, you know?
A. I think what’s happening is that when you buy them, they’re all juiced up. They’ve been growing in perfect conditions-
A. … with lots of fertilizer. And they’re taking a year off because they’ve used up their energy and they have to rebuild.
Q. Well, and I even used to just throw them in the … like put the pots in the pantry or under the sink, or just like Nowheresville.
A. [Laughter.] I thought you were going to say in the compost.
Q. No, no, no, no, no. Just rest, as in total neglect really is what was going on. It wasn’t a great spot. So all right, so you-
A. You’ve always had good luck with Clivia, too.
Q. Yes, yes, yes. I have my grandmother’s old ones, from, you know, I mean we’re talking, I don’t know how old they are. They’re certainly 50 years old. [How to grow Clivia.]
Q. Isn’t that weird? Yes. Crazy. So all right. So there we go. Get an extra question and answer even though nobody else asked, I asked.
A. But they were all thinking about it, I’m sure.
Q. Yes, yes.
unhinged by squirrels
Q. So should we take maybe the easiest question that was submitted first? Or I don’t know, maybe it’s the hardest question, depending on how you look at it …
Q. … which is squirrels.
A. Oh my gosh.
Q. I know. I know. Marianne wrote in:
“For the first time last summer, squirrels ate my tomatoes as soon as they started turning red or yellow or just plain ripe.” Her neighbor had the same problem. And she said, “Of course squirrels have dug things up in the past, but nothing like this,” and she wonders, as does her neighbor, is there some way they can keep the squirrels off the ripening fruit. Must they cage each plant with chicken wire, etcetera?
So I mean, what do you … I know what my answer is. My answer’s flip and rude, right?
Q. … which is that there’s no hope. You know what I mean? I mean, squirrels are demonic.
A. Squirrels are demonic, yes. And as you might know, when I was working on this house, where I am now, I rented another house, and there were chipmunks, and the chipmunks ate the … they didn’t eat the whole fruit, you know? They just ate like a third of each fruit.
A. I suppose one thing you could do is pick them green and ripen them inside, but then what’s the point?
Q. Right. No, I know.
A. And years ago, many years ago, I used to use mothballs. But mothballs are bad for us.
Q. Oh they’re horrible. And you know they’re labeled, it’s illegal to use them for other purposes than in a container in the closet. [Why to never use mothballs for pest control.]
A. Yes, if you can even get them, because now I think they’re banned in some places, too.
Q. Right. They’re super-dangerous. Yes.
A. However, when I planted the woodland garden, you were saying about squirrels digging up stuff, etcetera. And I probably mentioned this before, but I used dryer sheets.
Q. Yes. That’s what they say, and I’ve done that sometimes in my tractor, and this is against mice and chipmunks and whomever. But in my tractor, in the barn, for some reason they love to go in the engine compartment [laughter] and make a nest—and probably people have had it under the hood of their car. And dryer sheets are one of the things that is recommended.
However, I mean, I don’t think we can necessarily dis-incent all the local squirrels from all of our outdoor plants with, I mean, an infinite number of them.
I mean, the caging really is what she, what Marianne is hinting at. The caging is the only thing, and even that is not a great solution.
Q. It becomes ridiculous. So we don’t have a good answer, do we, because squirrels really are a nuisance.
A. Maybe grow more plants. No, that’s not a good idea.
Q. Yes. But I think you’re right about, it’s either caging or it’s harvesting a little early and ripening indoors, unfortunately.
A. Right. Right.
Q. Susan, in the comments on the website, asks a question about propagating philodendron. She says, “I want to learn how to propagate philodendron. Can I do it with cuttings in water?” Is that something that you’ve ever done?
A. I know you hate these yes and no answers, but yes.
Q. O.K. All right, good, we’ll move on to the next question. [Laughter.] Next!
A. You know, there’s very few things that I’d propagate in water, because the roots that form in water are unlike the roots that form in a medium such as perlite, something like that, which is fibrous and thin. But the roots in water, as everyone’s noticed, are kind of thick and white, because they have to get oxygen out of the water, which is a completely different kind of medium, if you call it that.
Q. You know, I remember coming to your house in Brooklyn, lo these many generations ago [laughter], when you had your garden in Brooklyn. And I remember on the windowsill you had a glass of something propagating, and it wasn’t really propagating. What it turned out to be was willow twigs in a vessel, in a water jar, and you were making willow water, you told me. Is that a true thing?
A. Yes. That is a true thing, because willows love water, and they do root in water. And it’s one of the few things that I actually root in water. But they have hormones, natural hormones, and they encourage things to root. So I would use the willow water as a kind of organic rooting hormone to help some things along.
But as I’m thinking of this, and we’re talking, I root some begonias in water, and I root philodendron vines in water. But I think an important thing is to then move it to a potting medium when the roots are between 1 and 2 inches long. Don’t let them be in there for years.
Q. Right. Don’t get spaghetti.
A. Because they’re just not going to make the transition easily to a medium that you want them to be in. Because they can’t … well, the philodendron could live for years in water, but it’s not going to be a pretty plant.
Q. But I’m inferring that you have other tactics that you probably would recommend more? Is that-
A. I think water for the vines is fine.
A. I’ll just tell you, I got asked that question recently.
Q. Oh, how funny.
A. And someone said, “How come it wasn’t rooting?” And the answer was “winter.” And he said, “How do they know?” They know.
A. Almost everything knows. They kind of take a semi-dormancy, and things that’ll root really fast in the spring will just sort of sit around.
Q. Well you just said the word hormones, and I’m assuming that daylength and whatever triggers things—the triggers to grow have to do with probably the release of certain chemical elements, they probably are some kind of hormones, and if those aren’t in plentiful supply, it probably doesn’t happen, right?
Q. O.K., so vining philodendron, we can put it in water. But get it out soon enough, before those roots become total spaghetti, or thread filling the whole jar. [For more: Step-by-step rooting houseplant cuttings in water, from Missouri Botanical Garden.]
growing fragrant violets
Q. Are you propagating anything else over there? Because you’re the author of, of course, “Making More Plants,” as I always like to tell people. That’s why I always ask you these propagation questions. [Laughter.]
A. I’m propagating a lot of things. I haven’t started a lot of the seeds for summer yet. Because as you know, some of them take, want to be under lights for 5 weeks, and we’re not there yet, 5 weeks before frost.
But I’ve gotten really into trying to track down fragrant violets.
A. And when was the last time you smelled a violet that had a smell?
Q. Yes. So you mean, perennial outdoor kind of things, not African violets, just so people aren’t confused. Is that what we’re talking about?
A. Well, they’re perennial, but they’re zone 7 I think.
A. So I’m going to have to be careful how I grow them. And I’m going to grow them in pots. But I got some Parma violets. They used to be, 100 years ago, there were 20 kinds of fragrant violets. They’re double. They smell incredible. You know, people talk about violet smell, but who’s ever even smelled a violet?
Q. Right. Anymore. Right. Right.
A. Because for like 20 years, there haven’t been any.
Q. So you got these from…?
A. I got them from Select Seeds. [Above, photo of Parma violet ‘Duchesse de Parme,’ from Select Seeds.]
Q. Yes? And you got little plants or you got seeds?
A. I got little plants.
A. Actually, I don’t think they make seeds, because they’re double-flowered, so I think you have to propagate them vegetatively. And they grow in a way, they kind of make runners, like a strawberry a little bit. Or not quite like a spider plant. But they make little runners that say, “Root me. Root me.”
Q. They say that? [Laughter.]
A. You can just look at them, and imagine they’re going to be rooted.
Q. And you’re drinking what? [Laughter.]
A. So I don’t cut them off from the mother plant. I put a little pot next to the pot, and with a hairpin I pin the little plantlets that are growing on thin little side shoots [photo above by Ken Druse]. There’s a place where they just look like they’re going to be new plants. And I pin those to a medium that I keep moist.
And then when they start to show new growth, they’re rooted, and you can cut them off from the original plant, and then you have more. And what am I going to do with 30 violets? Well, I think they’ll make great gifts, don’t you?
Q. Yes. So now these plants are next to each other.
A. Right. Next to each other. And you can picture with a spider plant has all the little spiders.
Q. Yes. So it’s like a baby.
A. Yes. You just can put some pots around, and have the pot, the mother plant in the middle, and then peg into some soil. They’ll root in. Spider plants would be easy. Strawberries would do it too, you know that awful ‘Pink Panda’ strawberry, if you ever wanted more of those.
Q. Yes. Huh. So the mother plant gives off little baby plants.
A. Yes, and I call them daughter pots.
Q. Oh good. All right. So fragrant violets, a great way to get more of those, if one invests in some. All right.
A. Well, there used to be 400 greenhouses in Rhinebeck, New York, that would grow violets and send them down the Hudson to New York City for the ladies, who would take them to the opera when they wanted to smell nice things, until about 1910.
Q. And not anymore. All right.
A. Not anymore.
Q. Well at Ken’s house, they’re happening, so-
A. We’re bringing them back.
moss in the lawn and the beds
Q. I got a question from Ann from Wisconsin, Zone 5. And she said she has moss, and she … This says moss has even invaded some of her grass. It seems to be everywhere, not just shady spots like it used to be [since shade is one reason moss forms in certain areas]. And she’s wondering, so it’s in perennial beds, and it’s in the grass. And she’s wondering why, and so forth.
And so there’s one kind of obvious, you know they say “read your weeds.” Sometimes they say you, like you can sometimes infer from what weeds show up, what conditions are out of whack. And one is, of course-
Q. Yes. So that it may be too acidic. The area might need liming or whatever. But it’s an indicator, it can be of other conditions too, like did the soil there get water, in these areas, get more water-logged? Has something changed in the way the area drains? Or is there more compaction?
Q. And you know, so either something uphill from there changed, or something else that has reduced the organic matter in the soil. Let’s not mention invasive worms again, but … O.K., whatever. [Laughter.]
Yes, so, and I think, so looking at all those things, compaction, drainage, like you said, acidity. And then, I think, cultivating, right, as well. I mean, breaking it up. But compaction, that’s where I see it the most, where I see that happen, even if nothing’s changed in the pH specifically. Do you know what I mean?
Q. It’s the compaction that does it. Yes.
A. So maybe it’s an area of lawn that they walk on a lot or something like that.
Q. Exactly. And that’s what I find, where I get it. Exactly.
A. When you have a garden tour, right, and your lawn gets all pressed down.
Q. I know. What a mess.
A. Usually, when we have moss, we’re thrilled to have moss if it’s in the right place.
A. But if it’s in the wrong place, it’s in the way. You know, I think that liming … well doing a soil test might be a good idea, because-
Q. Good idea.
A. Grass wants it a little alkaline, and moss wants it a little acid. And I think she could probably just put some lime and some compost over those areas, and see what happens. I don’t think she’d have to really churn it up a whole lot. We’re not there though.
Q. I was thinking in the beds, in the perennial beds and stuff, she might have to do a little cultivation, and like you say, adding compost and so forth.
Q. We have a question from Marjorie in Beaverton, OR, who wrote in the website comments, “Have we ever battled Canada thistle successfully?” She has a patch of it that she dug out last year, and now it’s back and spreading.
We should say, first of all, that it’s Cirsium, is it arvense, a-r-v-e-n-s-e, Cirsium. It’s an alien plant. It’s not a native American thistle. And there are really good, really important American thistle species. So one needs to do an ID first, before attacking your local thistle. O.K.? So we’ll just put that as the caveat, right? [Get The Xerces Society’s native thistle guide.] [Canada thistle photo from Wikipedia.]
A. Yes. But this is one of the worst.
Q. Yes. This is the worst. This is the worst. And actually, that species name means it’s of cultivated fields, which means it’s a widespread weed. You know what I mean—it gets out there and goes crazy. So it’s really a bad news one.
A. And she said she tried to dig it out, or dug it out.
A. But it’s one of those ones where you leave a little piece of the root in-
A. And you got another plant.
Q. Correct. Correct. It turns out, I read a little bit about it, and last year I was reading about thistles. And even in it’s native range of like southeastern Europe and parts of the Mediterranean, it has no effective natural enemies, and it’s considered a severe weed in agriculture there, too. So boy, you know it’s bad then, when it on top of that gets to another habitat. So-
Q. Yes. So have you ever tackled it?
A. Yes. [Laughter.]
Q. And, what did you do?
A. I used a chemical.
Q. Well, it’s interesting that you say that, because, I’m always, you know … I don’t want to use any, ever. And this sort of gets to the ethical thing. And that’s right philosophically. But even the conservation organizations, like if they’re doing a restoration, reclaiming an area that’s badly invaded with alien plants—they will have instructions, and they will be using them, for the greater good. Not all the time. They’re not relying on it all the time. But they will, in order to try to take back from a terrible invasive, they will do that.
So I think you’re saying the same thing. You’re not out there doing it all the time, but with something like this, you know you can’t let it get out of hand.
A. Well, and I take a sprayer, and I make a very thin stream, and I go right up to the plant as early in the season as I can, so I’m not really getting anything else, because it’s up pretty much before everything. And I just give it a little spot of glyphosate, right in the center of it, and that does help knock it back.
Also, it hides. So you get the ones in the front, and look back. Look in the back of the border, because they’re back there, too, and I try to get them as much as possible.
Q. So in doing some reading about it, there’s a way that if one decides to, in this case, use a chemical, learning the timing, the life history or life cycle of the individual plant we’re trying to target is super important. And in the case of Canada thistle, it turns out that the best times to direct that targeted spray, what you’re talking about, are between the bud stage and the flowering stage—not before bud stage, when it’s just at that rosette on the ground.
A. Oh. Hmm.
Q. Turns out, because the plant has already sent a lot of its energy up into making the bud, preparing to flower, so it’s a little weakened and vulnerable. And then, even more valuable time or targeted time is as it’s starting to decline a little bit, sort of the end of the season, when it’s going to pull all the chemical down into the roots.
Q. Yes. So it’s real interesting to read up on the exact timing, because you’re doing the right thing, but then each plant has this specific timing. And places like Oregon State University—our questioner is out in Oregon, so I was interested in is there anything special in the Northwest—or various universities talk about mowing every two weeks to three weeks for a whole growing season. And it can take years to eliminate it that way. [Laughter.]
Q. You know, they’re talking about agricultural situations. But the combined approach: almost all the university extensions are recommending a mechanical, like a digging or a mowing, repeatedly, repeatedly, repeatedly, plus an herbicide—a combined attack.
A. Can you give some directions on how we can find that information?
Q. Two good ones among many:
- From Penn State, a fact sheet on controlling Canada thistle, including mechanical methods and the critical timing of herbicide applications for best effect.
- Purdue’s fact sheet on Canada thistle control also outlines a combine approach–mechanical plus targeted chemical application.
Q. I hate using the chemicals, like you said. But there are times when, for the greater good, as I said, I think we have to talk about, as part of sort of an Integrated Pest Management, directed, tactical approach, using the least-toxic methods, but for the better result rather than just letting these things run in abandon. And you’re right that every little bit left behind will potentially sprout a new plant, so it’s especially bad, especially bad.
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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 the April 9, 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).