MORE URGENT GARDEN QUESTIONS: In the July edition of Ken Druse’s and my monthly Q&A radio podcast, we answered readers and listeners curious about the wonderful tree called Stewartia and how to make it happy—plus Ken recommended other garden-sized, multi-season trees to consider adding to your landscape.

In Part 2 (transcript at this link coming shortly) we tackled powdery mildew prevention and aftercare, and what to do when an abundance of roly-poly or sowbugs and pillbugs has descended on the garden. Should you use copper-based fungicides against tomato blight—and what to do after an infestation by the garlic bloat nematode?

Ken, of Ken Druse dot com, is a longtime garden writer, author and photographer and all-around great gardener—and great friend. If you have a question for a future show, you can submit it in the comments on either of our websites, or use the contact form to send us an email from either site, or ask us on my Facebook page.

Read along as you listen to the July 10, 2107 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).

Note: This is Part 1 of the two-part show, in which we talked about Stewartia care and other recommended small garden trees, including great dogwoods, redbuds, and tree lilacs; again, Part 2 is at this link.

And a small apology: The sound in Part 1, especially, is a little uneven; we had an electrical brownout in the area while taping and lost our master audio file. The backup that survived this unique power event was not ideal, but the transcript is thorough.

part 1 of the july q&a with ken druse

a question from margaret for ken

Q. Before we get to the reader questions, I have one for you, Ken. And I mean, it’s really urgent—and not only urgent but philosophical and existential:

Do you ever get to the end of your to-do list?

Ken. No because there is always something being added.

Q. It the damndest thing, working with a medium that grows the minute you turn your back on it, right? It regrows. [Laughter.]

Ken. People say, “I can’t wait to get the garden done,” and I think: “What are you talking about?” It’s never done, and we don’t want it to be done. It’s something you can do for a lifetime, crawling around the garden as I am doing this week because I’ve got my back issue, so I am crawling around.

Q. So you’re crawling because your back is bothering you, and I’m crawling because I am on a bittersweet hunt. I’ve got all these big shrubberies, like 20 giant shrubs in each island. And you know the birds find the Oriental bittersweet growing somewhere, they gobble up the berries, and then they sit in one of my shrubs in the middle of a bed and then they poop—and then I get hundreds of bittersweet seedlings. And that’s what I am doing. I’m exhuming, excavating, ex-communicating bittersweet. What are you doing?

Ken. I’m pulling some of them, too, and they have yellow roots as you may or may not know.

Q. Yes, orangey-yellow, very characteristic. [A tiny segment of Margaret’s recent haul, above.]

Ken. And that’s good, because when I pull it and I think uh-oh, what did I pull out? And I see the yellow—I think they’re yellow—and I think, “Ah, yes, I pulled the right thing, instead of that million-dollar vine I just planted.”

Q. Right. [Laughter.] What else are you up to on the to-do list?

Ken. Well, I had to make a list of the small trees that I have, and I tried not to make a list of small trees that I want…

Q. And we’ll talk more about that list later, I know.

Ken. That’s exciting. As you know, more and more these days I am into the woodies. They say that those herbaceous things are perennial, but I find that a lot of them don’t come back so I’m not sure if they are annuals or perennials. But the woody plants: They do it for me, and they don’t need a whole lot of care. And when I prune them if I have to prune them I like it.

Q. You know our mutual friend Marco Stufano, who was the founding horticultural director at Wave Hill, the public garden in the Riverdale section of the Bronx in New York City, he says that we are in the “shrub season” of our lives as we become older gardeners. The shrub season is when you don’t want to mess around with a bunch of fussy perennials, but the shrubs really are satisfying. They give you a lot, as you said; but they don’t demand that much and you can do some tinkering.

Ken. And you can shrink your garden. Some people think their gardens are too large, and they want to move to an adult community or something, and I just say: “Shrink it.” Put some more deciduous shrubs along the outside of the garden.

I have a Kolkwitzia here that’s probably 20 years old, and it doesn’t bloom for very long unfortunately but I have never touched that plant. I have never watered it, I have never pruned it—it probably needs a pruning. It’s bigger than a Volkswagen beetle.

Q. It’s beautybush, they call it—it’s sort of an old-fashioned favorite.

Ken. Yes. You know, you’re saying these things and I am thinking of what’s kind of on my mind, and something that’s on my mind is killing plants. You mentioned Marco, and he is a real gardener, a real professional gardener. If he’s tired of something, he’ll just get rid of it. He’ll give it to someone, or he’ll just put it on the compost pile.

I’ll have this half of a basil with two brown leaves and one little green hope at the top, and I’ll coddle it and coddle it, and then after six months it finally croaks. But I can’t seem to toss it. That was just an example, not necessarily true.

Q. One of Marco’s other quotable quotes, to that subject, is, “Bury your dead—and fast.”

Ken. [Laughter.]

Q. Like in other words, when they’re limping—don’t even let them croak, but put them in the compost heap.

Ken. Good idea.

growing stewartia

Q. OK, we can get back to our complaining, moaning and laughing, but enough of our saga of chores unfinished for the moment. I believe we have a caller on the line, Ken, named Robert. Where do you garden, Robert?

Robert. I have a garden-floor apartment in a brownstone in Carroll Gardens, Brooklyn.

Q. And what question brings you to us today?

Robert. I have these Stewartia trees, a pair of them that I planted maybe eight or nine years ago. They have taken off and they are really healthy. The question is that I have had many seasons with them, but this year for some reason there is a profusion of blossoms like I have never seen before on both of these trees. It’s all happy news.

Q. and Ken. [Laughter.]

Robert. But my question is why? I didn’t do anything to deserve this. I didn’t fertilize, and I also am not a big waterer. This is the third incarnation of this garden for me, and this is like the low/no-maintenance garden. Where I used to be spending hundreds of dollars a year in perennials, now it’s all ferns and Astilbe and hydrangeas that come back and these two Stewartia in the center, kind of making a vertical screen so the place feels deeper or more mysterious than it actually is. [Laughter.]

Q. Nice.

Robert. A foil. So the blossoming is the question I have, because I just don’t know what made for it; there was just no kind of change back here, really.

Q. So you didn’t do anything. And these are Stewartia pseudocamellia, I assume, since you are growing them in Brooklyn. Ken, have you grown them; do you have any insights?

Ken. I never got one because I thought it takes too long—it takes a long time to bloom, and then another 20 years and you see the beautiful, patchy camouflage bark. So I always thought I’m not going to live long enough. And that’s crazy.

About two years ago, I planted one. It’s only about 4 feet tall and it’s got buds all over it. I think there are a lot of reasons, perhaps, why your Stewartia are blooming. The main one is that they are older, because they do take a long time to bloom generally.

I also wanted to mention that pseudocamellia, the specific epithet, is “false camellia,” because it has big white flowers that kind of resemble single camellias.

One thing is that time—they are older plants. Another thing I don’t know if a tree in the neighborhood was taken down and they somehow got a little more light. Another thing is that we have had a wonderful spring in the Northeast, with almost an inch of rain every week, so a lot of things are doing well.

Robert. I have heard that all over. I was in Sag Harbor for the weekend, and in my friend’s garden we had a cocktail party, everyone admitted that the garden looked better than ever. And she’s also a lazy gardener that hires other people to do things.

Ken. [Laughter.]

Q. [Laughter.] It happens to the best of us; we all need to turn to some help now and again.

Robert. Oh, my, I feel like I like that option more and more.

Ken. Oh, no, you wouldn’t; come on.  Then you couldn’t complain as much. [Laughter.]

I do want to mention one more reason why it could be blooming heavily, which is not a wonderful reason. We had two dry summers—two dry, hot summers in a row, with drought, really. Last summer was very hot and very dry, and I lost a lot of plants that just didn’t leaf out. But sometimes flowering trees will put on a big show because they are trying to guarantee the future of the species by making fruit [or seeds], so some plants that are stressed will for into a big, mature blooming phase to guarantee the future. So that’s another reason why it could have happened.

But I think this all sounds like good news. But I think you must be a gardener because you are apologizing [laughter] and kvetching about something wonderful—and that makes you a gardener, don’t you think, Margaret?

Q. Yes, yes. So Ken you are saying age, of course—and I had read somewhere (and I hope I am not confusing this with another species of tree) that they don’t even bloom till like 11 or 12 or something not early, early, the opposite of something like Magnolia which is what is called “precocious,” where you can have this tiny little twig practically with this one giant flower on it.

These are kind of the opposite. And sometimes, as you say, Ken, light conditions can change because of something in the environment beyond your yard has changed. And more moisture. I am in a different place, Robert, a couple of hours north of you, and mine is blooming pretty heavily. I have had it for 20-something years.

Robert. Oh, wow. How big is yours?

Q. 20-something feet. But I would say that generally speaking that dry years are the worst on this tree. And it kind of makes sense when I look at those buds, which are like big white marbles. They are not teeny—you’d have to get a lot of moisture to hydrate that and unfurl that.

Plus like a lot of things in that Tea family [Theaceae], which the camellias are in, don’t they like open each bloom for like a day and then it falls off?

Robert. I thought there was something wrong with them but then I read about them, and that’s sort of its habit. I’m charmed by the way they don’t fall off by the petals, but it’s sort of like this ballerina dress that sort of drops onto the ground.

Ken. [Laughter.]

Q. Ken, am I making this up or are Stewartia and camellias in the Tea family? Aren’t they all related? If you’re in a camellia greenhouse, there are all these flowers on the floor, but there are many still on the tree. It blooms sequentially, more like daylilies do.

Ken. So you have to get a bowl of water for the center of the table, and have a party, and float some blossoms in the water for that evening.

Q. [Laughter.] I want to ask you, Robert, about your experience with your two 8- or 9-year-old Stewartia…

Robert. It must be older, because I am looking at it and it is probably 16 feet.

Q. Well, it probably had 5 or 8 years on it when you got it. They have been in a nursery somewhere, which is why plants are expensive and rightly so in many cases. But anyway—because of Google searches I get a lot of visitors about Stewartia, because I have a few articles on the website about them. People ask about pruning them. Have you ever pruned yours?

Robert. I just did that.

Q. I just had a question from a reader called Nabat, who says:

“I have moved into my new place and the Stewartia is looking very healthy and has plenty of buds so I am looking forward to the flowers. However I would like to know if I can prune it in autumn or please let me know what is the good time to prune. It has grown very wide.”

Robert. I don’t want to say I know what I am doing.

Ken. [Laughter.]

Q. But what promoted you to prune yours?

Robert. They were getting big. I bought them because they can have a sort of vertical habit, almost like birches, and because the branches were heavily laden with blossoms I wanted to wait till that was almost complete.

I pruned up to expose more of the trunk and bark in this Brooklyn garden, so that the whole place wasn’t consumed by these trees. I’m not sure; I know a little about pruning but I am no expert.

Q. This is a tree that has a very distinctive shape. People frequently like it for its natural shape, and you don’t want to hack back the ends of all the branches, right Ken?

Ken. Absolutely not. I would prune it after bloom as Robert has done, and if you need the head space then limb it up a little.

Q. To expose the trunk as he has done.

Ken. Maybe you want to walk there. [Laughter.]

Robert. I do.

Ken. It’s a small garden, so I don’t think you have a whole lot of choice, and in this case you’re going to see more of that beautiful bark.

Q. But this is not a tree to shear, and that is important with trees with such a distinctive shape.

Robert. What I did was look at the proportion of the thing and then select a branch that needs to have something happen to it, and take it back to the trunk.

Q. I’m so glad you called us with your Urgent Stewartia Question, Robert.

Robert. [Laughter.]

Q. It was great to talk to you.

other favorite garden-sized trees

Q. I didn’t know, Ken, that you didn’t have a Stewartia in your old garden or your current garden until recently. But as you were saying earlier, you are more of a woody plant person—and you were making a list recently of favorite small trees.

A lot of times they talk about this Stewartia as a choice small tree for a garden—meaning it doesn’t get to 60 feet or 100 feet.

Ken. Right, 35 feet. [Laughter.]

Q. Are there others you treasure this way? And I guess we should have said: Stewartia pseudocamellia is a multi-season tree.

Ken. And you get fall color too, don’t you?

Q. Absolutely.

Ken. So you get [July] flowers, exfoliating bark, fall color—I’d call that a four-season tree.

Q. Plus, that it’s not a 60- or 80-foot tree makes is a choice garden tree for all seasons. What are some of the others that if Robert had more room we could convince him to try? [Laughter.]

Ken. Well, sometimes you can’t be stopped, but it sounds like he can be.

All the dogwoods—that’s the first thing that comes to mind are the dogwood trees. We’ve talked about Cornus kousa ‘Wolf Eyes,’ which I adore and has done so wonderfully for me. I got my first one at Trade Secrets near you. [Ken’s tree in his garden today, below.]

Q. That’s like a garden trade fair or spring festival in Connecticut.

Ken. And it’s a fundraiser, for charity. I think it was about 3-1/2 tall and now it’s 12 feet tall and 10 feet wide, and it’s one of the most beautiful things in the garden.

Q. Describe it.

Ken. Last year it was covered with flowers for the first time after a bad summer, and this year it has quite a few flowers. It’s gray-green, with a creamy white edge on all the leaves, and it’s very dense. I’ve got it in about half-day sun, which is another thing about that Stewartia—that can be a tree for when you don’t have a lot of sun, because it doesn’t like a lot of sun.

Q. It can do in a non-baking situation.

Ken. So I’ve got that Cornus kousa, I’ve got several Cornus florida, which are the Eastern flowering dogwood—though one of mine comes from the mountains of Mexico.  There are the Rutgers hybrids—do you know about those?

Q. Yes, and they are again dogwoods, and hybrids between…

Ken. Well sometimes it’s a hybrid between Cornus kousa and Cornus florida, but sometimes it’s a hybrid between Cornus florida and Cornus nuttallii, the Western dogwood. They are a little bit bigger, but they are disease-resistant, which is how it kind of started, because the Cornus florida, if you have it in a place with not such great air circulation or a lot of trees around it, they can get anthracnose. It disfigures the leaves and could ultimately kill the trees.

A lot of people grow dogwoods in the middle of the lawn, and they love that, which actually a Stewartia would not like that. Too much Nitrogen.

Q. The variegated Cornus kousa ‘Wolf Eyes,’ I killed that tree. It was anthracnose—so I guess it wasn’t me, actually. It was a wet, tricky year and the native dogwoods around me had it. It’s one of the kousas that is more susceptible to anthracnose, I learned posthumously, when I did some research to find out why this happened to my tree, because as you said I thought kousas, as well as the hybrids, were a little more resistant than our native species. Sorry, I interrupted.

Ken. I‘m going to pretend that’s not the case. I’m just going to ignore that horrible thought about this tree, which is really a focal point of the garden.

I have a lot of Cercis, redbuds—and I have a couple of white redbuds, which I always think is funny to say: “I have a white redbud.” But I do; I have white redbuds, and I have ‘Forest Pansy’’—do you know ‘Forest Pansy?’

Q. I do know ‘Forest Pansy,’ and I have not grown it successfully—but I do know it. [Photo above by Ken of ‘Forest Pansy’ redbud’s purple leaves in distance.]

Ken. You have not grown it successfully?

Q. No.

Ken. Because it croaked?

Q. Yes, I have killed a lot of things in my time, Ken.

Ken. This is good to talk about because ‘Forest Pansy’ tends to croak, and a lot of people are beating themselves up because they don’t know why theirs did. I had one that I planted here and it became the largest ‘Forest Pansy’ I had ever seen, and it croaked.

You kind of have to think: where did this plant come from?

Even though Cercis canadensis grows from way down south to way up north—into Canada—that doesn’t mean they are all the same. I think ‘Forest Pansy’ might come from a part of the country that’s kind of specific, or maybe growing on rock. I’ve noticed that a lot of Cercis like to grow in shallow soil, on rock, so if you plant it too deep or in a wet spot, that might contribute to its demise. I think in my case being under water might have contributed to its demise—because it was after the big flood here.

[Apparently Ken is correct; ‘Forest Pansy’ was discovered in 1947 in McMinnville, Tennessee, as a chance seedling at the former Forest Nursery.]

We could talk about Japanese maples, but we can’t because this show is not six days long.

Q. True.

Ken. If I had to pick one Japanese maple I would say Acer japonicum ‘Aconitifolium,’ and it’s called ‘Aconitifolium,’ because the leaves are feathery and deeply cut like the leaves of Aconitum—monkshood. But it has just about the best fall color of any tree, I think; the leaves are green and beautiful and it’s so easy to grow. [Photo above from Ken Druse.]

The color almost bleeds through the leaves over a period of about two weeks, and it’s orange and yellow and rich green and blood red and kind of a maroony-purple all at the same time. And it’s so easy to grow and dependable, and when I say small—because you can get a Japanese maple that stops at 2 feet—this one grows to probably about 25 or 30 feet. And they are beautiful—beautiful bark and everything. I can’t say enough of them.

Am I talking too much?

Q. Will you just please be quiet? [Laughter.]

Ken. Have you noticed? Everybody used to plant those awful Bradford pears everywhere…

Q. The Callery pears.

Ken. …that split in the snow and the ice. Well, I’ve noticed that cities and towns are planting the summer-blooming lilacs, the tree lilacs.

Q. That’s a good small tree; I used to have one of those, Syringa reticulata—is that what it is?

Ken. That’s one of them, and there is also a subspecies pekinensis, and the bark looks like cherry but it exfoliates.

Q. It’s almost a little metallic, like coppery-bronzey the bark; nice. And it has big plumes.

Ken. Yes, big plumes; they don’t smell like regular lilacs, but more like privet. [USDA photo above from Wikipedia.]

Q. I lost mine of that too, not having anything to do with my killing it but there was underground work with power lines that had to be trenched out and it destroyed the root system of that plant, and it had to be moved. I am thinking of getting another one.

Ken. It’s such an easy tree to grow. And it makes a nice shape all by itself—so it’s kind of plant it and forget it. And it blooms later than a lot of the flowering trees. I think that’s a winner, especially for something to plant and not even think about, and then you think about it when it has these giant creamy white plumes. And there’s even one that has yellow flowers. [Some of Margaret’s favorite small-garden trees are profiled here.]

• In Part 2 of the July Q&A show: Powdery mildew, fungicides and tomato blight, garlic bloat nematode, and more, at this link.
  

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MY WEEKLY public-radio show, rated a “top-5 garden podcast” by “The Guardian” newspaper in the UK, began its seventh year in March 2016. 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 10, 2017 show right here. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).