cutbacks and more: keep the garden looking great when spring fades, with ken druse
A FAMOUS GARDENER Ken Druse and I know often says this one-liner: “Anyone can do spring.” What he means is: and then what happens after that?
What happens after the current tender colorful parade of beauty, with flowers everywhere and fresh green foliage expanding by the minute without our effort, is up to us gardeners—and that’s the harder part. That’s our topic today: what to do next to keep the garden going strong for the long haul, from pinching and shearing to pruning and other cutbacks.
Ken Druse needs no introduction except to say he’s been my go-to garden friend for decades, is the author of an amazing 20 books, all of which I have read, and he joins me once each month on my public-radio show and podcast.
Read along as you listen to the May 4, 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).
making the garden last past spring, with ken druse
Margaret: Happy spring.
Ken: Thank you. The last time we talked [about dividing perennials], how many comments did you get?
Margaret: Oh my goodness.
Ken: Do you remember?
Margaret: I don’t know. It was like 500 or something.
Ken: Something like that.
Margaret: A lot of pent-up garden energy out there. And actually I was going to ask you, speaking of that and this strange year that we’re in, have you been to a garden center yet this spring?
Margaret: No. And so I want to say I’ve heard from a lot of people, including in some of those comments that you just alluded to, about a lack of availability of seeds first, because all the seed companies got overwhelmed and then of plants and so forth. And you know in the trade press, which I read every week, the independent garden centers around the country have been trying to be deemed essential with safety rules in order. And in many states they are, some states they’re not. It’s changing by the minute, but a lot have curbside pickup, a lot of the independents, your local family-owned garden centers. So I think it’s worth calling, certainly looking at their websites, and calling.
My local place has been amazing to drop bagged goods, even deliver bagged goods, or throw them right in your trunk if you want to pop by with a prepaid order. So it takes some investigating. But I want to support these businesses and plus I need certain things to do some of the projects that I’m doing here.
Ken: Right. What you need is another deadline, right?
Ken: And now people can find you either online twice a week in “The New York Times,” or sometimes in the print version, oh my gosh, in spring with everything else.
Margaret: I know. That started like the last week of April or the next to last week of April. I know. It’s crazy out of the blue. So that’s something new. But yes, so I’m busy. But I’m also, as we’ve talked about before, like you are, taking advantage of this year when people are not visiting the garden to do some chores I’ve put off for a while, when I’m usually busy getting ready for tour. So…
Ken: I’m glad that people are not visiting the garden here because in April, the third week of April, it was in the 20s and the hostas were up because the winter was so warm and so many things have been, let’s say set back. I think some things may be have been killed. [Below, the aftermath of the hostas at Ken’s.]
Ken: But I don’t know what’s going to happen. And I was thinking: at least nobody’s coming. [Laughter.]
Margaret: Yeah, no, I know. I know. A lot of stuff in the mornings here at that same period of time were lying down, frozen solid, icicles. So I don’t know what will rebound and what won’t, but I wasn’t as advanced as you.
So it’s the first week of May or thereabouts, depending where people are living. It may be peak mid-spring or peak late spring or whatever, north to south and so forth. But there’s a lot of colorful stuff going on everywhere outdoors, flowering shrubs, trees, bulbs, perennials.
People did their spring cleanup or they’re doing it and they’re like, “O.K., I’ve done that—check!” But that’s not the end of the story.
I thought we could go through sort of some of the things that you and I, after a million years of gardening, have learned—sort of aftercare that really help the garden to look good right into the summer and beyond. So do you want to start with like bulbs, for instance? Because those are one of the big features of spring?
Ken: Well, I think that your listeners know that by now that you don’t cut off the daffodil foliage. You don’t mow them if they’re in the lawn, which is kind of too bad because it’s hard to get around it, and you don’t braid them. I haven’t… When was the last time you saw braided daffodil foliage? It’s been a long time.
Margaret: I haven’t in a long time, but I used to see people do it, you know?
Ken: But I have seen people who planted daffodils in the lawn, for that lovely English look, and then mowed the lawn and they wonder why they don’t have any flowers anymore.
Margaret: Right, right, right. So here, I’m in Zone 5B, I don’t even mow—I have big amounts of them in sort of grassy areas—and I don’t even mow those areas until around July 4th, so I really let them go their own all the way down to beige. [Laughter.]
Ken: And maybe if you have species tulips, that some of them come back every year—most, I don’t know. Most tulips don’t come back every year for me anyway, even the species. But if you have species tulips, you want to leave the foliage. You want to leave the foliage of all the bulbs, and most of them will tell you it’s over. Like the allium, the allium are blooming and their foliage is ugly and turning yellow at the same time. And so it’s pretty much over after they bloom.
Margaret: Right, right. So I let them “ripen,” as we would say. I let them do their thing and take advantage of their photosynthesis process before I clean them up. So that’s super-important.
Ken: And when they’re turning yellow, that’s when you do it. Or when they’re yellow.
Margaret: Right. And one other tip, I think with some of the little guys: Some of the little guys, like one of my favorites is the winter aconite or Eranthis hyemalis, tiny little first bulb to bloom with the snowdrops here for me, even March where I am sometimes. Yellow tiny flowers. It’s hard to establish, but when it does get established, the way it likes to establish itself and get into a bigger and bigger mass is by seeding. And so you don’t want to disturb that area when the flowers are spent. You know what I mean? Make a mess, clean up too roughly, because you’ll miss out on that colonizing effect that the self-sowing is going to do so.
Ken: And it takes a long time.
Margaret: It does. [Laughter.]
Ken: And then: surprise! But it takes a long time because I believe that those seeds need to… They take two years to germinate. They have to go through warm-moist, cold-moist, warm-moist, the whole thing like that… I think it is two years to germinate. But it’s one of those things in the garden, you don’t stand there tapping your foot, waiting to see the colony take off. You just go away. And then a scant seven years later [laughter] you have a nice big clump or a colony.
Margaret: Yeah. So flowering shrubs are another hallmark of spring. And oh my goodness. I mean, we could name so many that we adore. And the question always arises, do I have to deadhead them? I’ve been getting from people more Southern than I am, I’ve already been getting like, “do I have to deadhead my rhodies?” Do I have to dead head my… fill in the blank. Right?
Margaret: So yeah. Camellia is for more southerly people. Exactly. And that sort of … dot, dot, dot … is like also sort of when to prune them. When is the right time to prune them? So maybe let’s talk about, if you can imagine fast-forward in your garden a little bit, like some things that you do tidy up/don’t tidy up in the shrub department. Kind of how it pertains to their flowering.
Ken: Don’t tidy up. That’s a good one. Do you grow Spiraea, I think it’s thunbergii, the ‘Ogon’…
Margaret: ‘Ogon.’ The gold-leaf one [above].
Ken: Yeah, you don’t want to cut that back because the foliage is what you’re growing it for. It has lovely white flowers early, and they’re followed by these sort of needle-like leaves and ‘Ogon’ is the gold one and that’s a terrific plant.
So that’s… and actually forsythia, too. Don’t cut back forsythia. [Laughter.] I mean don’t make… You can cut out the part that’s deceased, but when I see a forsythia ball I just think, “Oh, what is going on?” And sometimes they have no flowers, because the landscaper has made them into meatballs, which is not a good thing for forsythia.
But other things, I mean camellias are kind of self-cleaning, like an oven [laughter]. The flowers turn brown and they sort of fall off. But you can help that along and just go to the flowers and just sort of snap them off. And if you need to you can prune it. But as we’re talking, I’m thinking the general rule, especially for spring-flowering things, is you prune them right after they flower, because they’re going to need the whole season to prepare to flower again. Some things like Hydrangea paniculata make the flower, what they’re going to flower with, through the season, but the early things they’ve made what they’re going to use to flower the year before. You really have to prune right after they bloom.
Margaret: So in our Northern gardens, one of the… and this is true everywhere, just the timing is a little different. The best time to prune lilacs, they say, is cut some bouquets and enjoy them indoors. And that’s your pruning, you know what I mean? It’s at the time or right after, because by say July, two months later or so, they are already beginning that process toward thinking about setting buds for next year. And certainly by fall there are buds. So you don’t want to do it then.
Ken: And there’s a lot of “should you deadhead lilacs or not deadhead lilacs?” And I think that if you let the fruits develop, you really don’t get as many flowers. At least I don’t. So it’s a lot of work. But I do think that as you said, cut some for on the nightstand, that’s the best. Some things that have fragrances during the day don’t have fragrances at night, but lilacs have fragrances 24/7, so cut them and have them on the bedside. And then if you haven’t cut them all, then go around and just, you can snap off little fruits as they’re forming, which are very easy to see. They’re green fruits where the flowers used to be. Or you can take your secateurs or pruners and cut them off.
And if you want to prune your lilac, I would prune it down to the first outfacing cluster of leaves. So you want to encourage the shrub to sort of get a vase shape. So that the next branch doesn’t cross with an inner branch or become congested. You want to open it up. And that’s pretty easy to see if you look at it.
Margaret: So when you prune in any case, you look to see the direction, what you’re leaving behind is likely to sprout and go in. Right? So that you’re thinking of the future architecture.
Ken: That’s mostly true with a shrub that has alternate clusters of leaves. Because some of them have clusters of leaves on both sides. So you can actually remove one and encourage that outfacing growth. Am I getting confused here? [Laughter.] It’s not so hard to understand.
Margaret: No. And with the lilacs, the other reason I like to deadhead them, so to speak, is that once those fruits as you call them, those clusters of green things are brown, they look like hell. Let’s just face it.
Ken: Oh, gosh.
Margaret: You have a big floriferous one that really performed beautifully, and then it has this mess. Ugh, right?
Ken: Yeah. But I try to get them while they’re green because you’re right.
Margaret: Right, because it’s awful. And I don’t want to look at that the rest of the season. And as you say, it may also reduce flowering; some of the energy may be put into the reproductive ripening of those seeds.
So the long-reach pruner, I love the one by the company ARS. I have no affiliation with them, but I just love their pruning tools. ARS’s long-reach pruner, it maybe gives you an extra… Well, you can get very long ones, but I have one that’s maybe 4 feet and another one that telescopes to 6, so I can get a lot of those even 8, 9, or 10 feet high, I can get a lot of those deadheads out of a lilac, which is great. And it’s a lightweight aluminum tool, so even for me, it’s not a hard thing to do. So I love those.
Ken: Are you going to put a link of what it is?
Margaret: Yeah, or I can show a picture of it. It’s a great tool. I mean, those lightweight aluminum long-reach pruners are spectacular. I mean, really, and I learned about that from an arborist years and years and years ago, a professional person who came to do help me do some pruning that was above my ability. And I saw the tools that they had and they were all this lightweight stuff—duh, I mean, of course, because when you’re holding something up in the air, you don’t want it to weigh 25 pounds. Right. So anyway, so flowering shrubs.
O.K., so we’re going to clean up the ones where we think that it may deprive the plant of some of the energy for the future or where it’s going to look like hell, as I said before. What about conifers?
Ken: I was just going to ask you that.
Margaret: You have dwarf conifers, don’t you?
Ken: Yes, I have some dwarf pines. And that’s really specific because you can’t prune every evergreen conifer. You can’t shear them. A yew, a Taxus, it has endless dormant buds. Well, you’ve seen yews that are 500 years old.
Margaret: You can cut them to the ground practically. It’s hilarious. Then you’ll get a new one.
Ken: But if you do that with a pine tree, you have killed the pine tree. You have to have green growth. And really the only thing you can do with a pine, whether it’s dwarf so you can reach it or if you have a ladder or now a long-reach pruner, they have new growth right about now that’s maybe 3 to 4 inches long and they call them candles. [Above, springtime candles on a Pinus parviflora at Ken’s. Below, after pinching.]
Margaret: I know, I love that: candles.
Ken: Yeah. And they’re going to turn into the whorl of sort of feathery growth that if you see on like a white pine and most pines—well all pines really have that kind of growth, whether they’re shortish needles or long. And you want to snap those candles in half or leave one-third. And it’s really almost the only kind of way that you can thicken up the growth on a pine tree is to the snap that candle, and that’s usually like… for us it’s about, I don’t know, second week in May, something like that.
Margaret: So it’s kind of like pinching, which is another good subject for this time of year. So it’s like pinching those candles, that soft growth before they develop. Yeah. So pinching is something that a lot of us skip because spring starts to demand so many chores, and we miss it. And whether it’s with annuals, or with certain perennials, giving them a little bit of a haircut before they’re fully developed, before they’re in full stature—and not all of them, but some of them, like you don’t do this with a lily, you don’t do this with a peony. I’m not saying pinch those, but a lot… I mean you probably know a lot that are good.
Asters for instance, a lesson I learned about asters I learned from the woodchucks, who love to eat asters, and they’ll be 6 or 8 inches high in May sometime, and then the woodchucks will come in and they chew down all the asters and I’m like, “Ooooh.” And then sure enough, it pushes up all this growth and it’s kind of bushier and a better stature, not quite so tall.
Ken: Right and garden phlox, too.
Margaret: Phlox. Exactly, the tall paniculata phlox. Right? Right. Helenium is another one. What’s the name of that sneezeweed or something? Heleniums… Those are good.
Ken: Yes. Physostegia, the false dragon’s teeth.
Margaret: Is that like… Do they call it obedient plant, too? These are all these common names. I don’t know the common names as well.
Ken: They’re terrible. [Laughter.]
Margaret: Terrible, yeah. The joke… Even Joe-pye weed [above]. If you have one of the ones that gets really tall and you want it to be a little less tall, you could even pinch that. Any others on your list?
Ken: Well, I know that people who grow dahlias pinch them and I have no familiarity with that.
Margaret: Yeah. My flower-farmer friend, Jenny Elliot from Tiny Hearts Farm here in Copake, New York, she always does. And she says she can hardly think of any “annual”—I mean the dahlia is like more of a bulb type of a thing, tuber, but she can hardly think of any annual she grows for her cut-flower business that she doesn’t pinch. The only one that she could really think of off the top of her head in a conversation we had recently, were like the celosias, the ones that get like the brain type of flower formation [and sunflowers don’t get pinched, either]. But basically, zinnias and marigolds, everything… Cosmos she says do really better after a pinching.
And what happens is when you wait until something gets to be, I don’t know, depending on the thing, 3, 4, 5 inches tall. And in some of the cases of the perennials it might be a little taller than that. And you take off maybe half the growth, or in the case of the annuals, you go down a bit so that you leave maybe three sets of leaves down below. You end up with… It breaks, it goes, it gets more stems, and if you’re a cut-flower grower, more stems is a good thing. And stronger stems, right? Not one or two big spindly things, but a more bushy, with lots of flowers being offered. So that’s kind of good.
Ken: Well, and if you’re growing a lot of herbs, you can do that, too. And you don’t have to cut them in half or cut them way back. You can just actually take your fingernails and cut the newest growth, and then the little dormant buds along the axils where the leaves are will wake up, and that’s what turns into a bushy plant. With a begonia, you want to do that with almost every begonia. If you’re growing the fibrous begonias in a pot or something.
Margaret: Right, right, right. But again, you don’t pinch a daylily, you don’t pinch a true lily. You don’t pinch. I don’t think you… You don’t pinch ornamental grasses, peonies, the bearded iris, the Irises. The phlox is such a great example, because almost everyone can visualize when a clump of phlox comes out of the ground, if it’s been in the ground while there’s a hundred or more little shoots, right, in a close proximity. And so you can imagine that that’s the type of thing, and asters are like that. They send up a lot and so forth. A lot of these daisy-like plants as well, so… I’ve even read that you can do it with Russian sage, Perovskia, is that right? I’ve never done it with that.
And then there’s the other form of… it’s not pinching but it’s sort of more deadheading or shearing that comes later. So some of the earlier perennials will have gone by and then some of the ones will go by in like late May in June. And if you don’t deal with them, the garden can really look like hell in July and August. Like catmint or the euphorbias or… It’s nice to give them a cutback after they finish blooming, right?
Ken: And so some of those things will bloom again if you cut them back.
Margaret: Right. I think the Nepeta does, the catmints will sometimes. Right? Yeah, I do it with my perennial geraniums, my Geranium macrorrhizum [above] that I use it as a groundcover. After it finishes blooming. I really shear it. I use hedge shears, I get down low and I clip, clip, clip with head shears because it’s too hard to do miles of it otherwise with just a pruner, one at a time.
Ken: So then it gets thickened up sort of?
Margaret: Yes. And it doesn’t get quite as tall, but in a way that’s better because it doesn’t kind of flop over onto things adjacent to it and so forth. So no, it just keeps it tighter and nicer. And I don’t have the spent flowers sticking up above the foliage. So rather than literally deadheading, pinching off one of 1,000 flowers, one every 6 or 10 inches around a huge sea of these things under some big shrub borders, I just take the hedge clippers and do it wholesale [laughter]. It looks like… Speaking of things that look like hell folks after you do them.
And I sometimes say that to make the garden last, you kind of have to make it a mess for a minute. So in two weeks it’ll look better, as long as you water well after you do it. So…
Ken: [Laughter.] My brain is swimming. There’s a lot to do.
Margaret: Yeah. I just wondered other things that you think of that help you make your garden keep going.
Ken: In the other years, you would go to the garden center and get things on sale, and plug them in. And maybe it’s something if you are going to get some plants from the garden center, even in your drive-by pickup, you might think of some things that may not be in flower but will be later, to plug in.
We see these beautiful perennial borders and we think, “Oh, how come our perennial border doesn’t look like that?” Well they’re taken out some of the bad things, and replacing them with some good things. Sometimes when you do have tours, sometimes I’ve put things in pots in bloom, just stick them in. That’s a secret.
Margaret: Yeah. Well and I used to say “Hosta pot. Why not?” In other words, if I don’t have something for a particular pot, and I do a lot of pot arrangements in sort of semi-shady or bright shady areas near the house. And I mean maybe I don’t want to go and buy $50 worth of something anyway, even if the garden center were open, to fill a pot. And sometimes I’ve taken my divisions from hostas and I’ve plunked them in there and it looks great. It looks great in a pot.
Ken: That’s a great idea.
Margaret: Do you know what I mean? It’s architectural, especially the bigger ones. So a young shrub, a shrub that you’re going to buy for the garden—but don’t plant it till the fall. Put it in a pot this spring and summer. Right? I mean improvise, I think.
Ken: Well there’s so much we can talk about. I know we don’t have time and like cool-season plants to start from seed later on. And what about all those houseplants you’re repotting and taking outside? We’ll have to talk about houseplants at some point.
Margaret: We will? Are you going to force me?
Ken: [Laughter.] They will force us.
Margaret: Yours have a much better life over there in your solarium than mine have here.
Ken: Where you summer the houseplants outside…
Margaret: Yeah. It is good. [A few begonias and water troughs with duckweed, above.]
Ken: It’s beautiful.
Margaret: That’s true. All right.
Ken: It’s sort of the introduction to your whole garden. I love it.
Margaret: It’s a deal. It’s a deal. All right, well thank you, thank you, thank you, Ken and like I said last time: I miss you. So, all right, I’ll see you soon. O.K.?
Ken: All right.
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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 April 27, 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).