ONE OF THE ITEMS on my spring to-do list: get more vertically creative—meaning, to use vines more often in the garden, and in more inspired ways. Dan Long calls that “vines off the trellis,” not just the expected use, but scrambling up into shrubs, or into trees, or cascading over walls—which I cannot believe I have never done—and even vines in containers.
The key is which vine for which use, because (hint): planting a trumpet vine or wisteria in your climbing rose bush probably isn’t a good matchup.
Dan Long joined me on my public-radio show and podcast from Athens, Georgia, where he owns Brushwood Nursery aka gardenvines dot com. Dan’s the person I know with the most vines—300-something over all in his collection the last time I asked, and more than 150 Clematis species and varieties alone. I suspect he has something for every possible use we can come up with, and that’s what we talked about in the March 14, 2016 show.
A link to a highly popular past interview with Dan, on how to prune Clematis, is at the bottom of the story.
my ‘vines off the trellis’ q&a with dan long
Q. One quick question I don’t think I’ve ever asked you before: What are the most popular vines—is it the Clematis?
A. Over all, we are best know for our Clematis, with a very strong showing in the climbing roses and the passion flowers.
Q. And on the other end—the yin to the yang [laughter]: You probably have some beloved vines that you don’t sell many of, but that you’d never take off the list. What are the most underappreciated ones, ones that you wish more people would give a try to?
A. Since moving south, I’ve really become enamored of the Trachelospermum—the genus that’s the star jasmine and Asiatic jasmine. [Photo above, detail of Trachelospermum ‘Hatsuyuki.’]
They’re not fully hardy in more Northern climates, but they’re really durable. The foliage is often very colorful and the flowers are fragrant. I’ve really come to love them.
One that comes up over and over again for me, is Parthenocissus henryana, [below] the silvervein creeper. It looks somewhat like our Virginia creeper, but is far more restrained in growth. It has beautiful silver venation on the foliage. It’s really quite nice.
Q. So that’s a lesser-known and lesser-appreciated goodie; I’m going to look it up.
A. Beautiful foliage all summer long, colors up nicely in fall, and it won’t eat your Volkswagen over the weekend; it’s much more restrained than our native Virginia creeper.
Q. [Laughter.] Since I have confessed to never having grown a vine in cascading fashion, shall we start there? Even though I have stone walls with planting beds behind them in my garden, shame on me—I’ve never done the cascading thing. Which vines do well trailing down as opposed to up?
A. When people have a wall they thing they have to plant at the base of it, something that’s going to cling to the stone like a Ficus pumila or a Bignonia. But plenty of vines will cascade just fine. Another one when we’re talking about foliage like with the silvervein creeper—one that I love for cascading is Rex begonia vine, Cissus discolor. [Photo farther down the page.]
The foliage is just outstanding; it’s beautiful. It’s plenty vigorous, and loves to fall off the side of something, either spilling out of a very large container or spilling over a wall. It’s very decorative, and very easy to grow.
Now that one is a tropical, so if you want to go for something that is going to live many years in a temperate climate, you can think in terms of something simple like Jasminum nudiflorum. It’s very hardy, an arching shrub that will cascade down quite a few feet very nicely. It’s going to go up, out and down—so it will take a fair of space in the process, but it makes a great background and blooms very early, and it is the hardiest jasmine.
Q. And the flower color is…
A. Yellow, and very early.
Q. That’s what I thought. A friend of mine has it by his front stoop, and at that time of year you come to the door and it’s like this effusion of this lovely yellow—not a bawdy yellow—and it looks like “Wow, how’d you get that to happen?” But of course it’s not a tough plant to grow, or some tender or delicate thing.
A. Very easy, very hardy. Some folks mistake it for forsythia.
Q. Forsythia! Not my favorite plant. I have seen some climbing hydrangeas spilling over stone walls in older estate-type settings, just like I have seen them growing up walls and houses.
A. Absolutely. I remember being in western Connecticut after seeing you at that benefit sale…
Q. At Trade Secrets—one May many years ago, right [photo above of Dan at the show booth in 2009].
A. Yes. We were touring gardens afterwards, and there was a beautiful climbing hydrangea that was cascading over a stone wall section just below a deck. It was actually what the owner called a visual and auditory block to the pump mechanism for the little pond and waterfall below it [photo below].
It in itself created a waterfall effect, and it was above a waterfall.
Q. You started by mentioning one of my favorite vines of all, the Rex begonia vine, Cissus discolor. I always grow it in a very big clay pot by my house [photo below], on a tripod of three tall bamboo canes. It’s well-named, I think, because the foliage is that stained-glass window red and green and silvery of the fancy-leaf begonias.
A. And the stems and petioles are very pretty.
Q. It’s a grape relative, yes?
A. It’s in that family, yes.
Q. So it has those tendrils or curly-cues that you are describing, and they’re wine color.
You brought up that it’s a tropical, and everyone who visits my garden says, “Oh, how do you overwinter it?” Well, to tell you the truth, I sometimes throw it away, or give it to a friend who does have a greenhouse, or to a public garden. I don’t give them the pot, of course; I’m a greedy-guts. [Laughter.]
But what I am saying is that sometimes I just discard it—I use it like an annual. It doesn’t have to be a perennial to be used in these ways we’re discussing.
A. I see folks all the time who will buy flats and flats of annuals, and they’re beautiful and they fill a little space at the front of a border. They could buy one of these single annual vines and cover a huge amount of space. It makes an absolutely beautiful display all season long—either with just the foliage, or often with flowers. So it doesn’t have to be a perennial; it can be for you to enjoy for those four or five months of the growing season.
Q. And as you point out: Even if it costs the same as a couple of flats of annuals—you going to discard those, anyway.
A. And your coverage—call it your beauty quotient per dollar—I think they’re a bargain.
Q. To move to another “vines off the trellis” idea: I suppose the classic image of vine-in-shrub is a Clematis in a rose bush like we see in pictures of English gardens. So let’s talk about how that works–and other ideas for shrubs and vine pairings. I suspect you’ve seen some great examples in your travels.
A. I have a friend who lives south of Atlanta and she has several hundred Clematis, and I think she has something like four or five trellises.
Q. [Laughter.] So hundreds of Clematis and only four or five trellises?
A. Yes. It’s a sight to see. These vines didn’t evolve to grow onto a trellis. They evolved to grow onto other objects—the ones that self-cling onto a stone wall…sorry, I mean a stone outcropping [laughter].
A. Right, a stone wall that nature built. [Laughter.]
Q. Then Clematis in particular evolved to grow onto other shrubs and small trees. Most of the hybrids retain that ability to climb. The nice thing about them is that most are very lightweight, and all off them climb and hold by wrapping their petioles onto other stems—the petiole being the leaf stem. It’s a very lightweight, non-damaging way to hold on to a host plant. It’s not twining and growing and choking the host plant, it’s just got a couple of fingers wrapped onto it.
Once it gets hold of that, it will find more of the stems, and it will cling onto itself as it branches out. They tend to have a very lightweight structure—most of them. We should talk about pairing mature sizes [of vines and shrubs or trees] in a second.
But in most cases you’re going to prune those Clematis back each year, so there isn’t a big horrible buildup that’s going to choke anything else. They’re really terrific.
You grow them up into a climbing rose, where it can hold onto the big, heavy canes of the climbing rose, and you can do it a couple of different ways:
You can grow a short vine, and maybe your climbing rose is really tall—like 15 feet tall—and it over time gets some bare legs. You can cover up the bare legs with greenery and pretty flowers.
Or, you can grow a taller one that’s going to match the height of the flowering portion of your climbing rose, and you can time the flowering so that you get a mix of colors in the same spot.
Q. You just hinted at a caveat with the pairings. I’m imaging that say Clematis montana is not one I’m doing this with—it might get too big for this purpose?
A. It depends on the host. This is where you want to be thoughtful about your pairing. You want to say: The Clematis montana, is it going to mature at 30 feet, 40 feet. Does it have a thick, heavy canopy? What would be a suitable host plant for that?
I have seen one trained beautifully into a tall pine tree at Chanticleer Gardens, and they do a fantastic job; they live well together. I believe in the case of that pine they have to do some supplemental fertilizing and irrigation, because the base of the Clematis is inside the drip zone of the tree.
Q. That’s a dry place, inside a conifer’s drip line.
A. Exactly, so they do some supplemental work in that case. But what they have done is paired the size of the vine with a suitable host.
Q. What I was thinking is that the montana wouldn’t be good in my rose bush—but it would be good in something larger-scale, as you point out. And the one that would have climbed the naked legs of my rose bush wouldn’t be substantial enough for the pine tree. So I have to make a good match.
A. Definitely look at the mature size. Go with a Clematis with a mature size up to 8 feet if you want to fill the legs of something taller. Or if you have a shorter climbing rose, such as ‘Joseph’s Coat,’ which doesn’t max out, you can have it climb up and bloom in multicolor with it.
Q. I have to confess I have them in some wacky things that probably aren’t on the list of top shrubs to put them in, but that I think are nondescript or even you might say ugly much of the season—like winterberry hollies. Winterberries are fantastic in fall into winter when the fruit is ripe, but there isn’t much to be said about them earlier in the season.
A. That’s an excellent way to grow them—you’re extending the season of color, or interest, by adding the vine. It’s the same thing going back to forsythia; it’s very boring the rest of the year. You can certainly train a little Clematis into one of those without harming it whatsoever.
Q. On a slightly bigger scale—and you were just talking about a larger Clematis in that pine tree at Chanticleer—other vines can also go up into mature trees. I have a friend with a Schizophragma going up a mature maple trunk, and it’s very beautiful because the foliage itself is beautiful—with some variegation maybe?
A. It might be Schizophragma ‘Moonlight,’ [above photo] with some nice pewter interveinal sheen; very pretty.
Q. It’s almost like he’s used the trunk of the tree as the trellis.
A. Absolutely. And those self-clinging vines evolved to grow right up into a tree, and the look great together. And unlike a wisteria, they won’t choke the tree.
Q. Any other such examples for up a tree?
A. A cross vine is a really beautiful one, Bignonia capreolata [above, ‘Tangerine Beauty’]. It grows very well up the bark of the trunk of a tree. It’s interesting; its leaf is divided into two leaflets, and a tendril out the center. That tendril can clasp onto stems or hold on stone or masonry or grab on to fissures in tree bark. It will grow on anything, basically…
A. …from a wire straight up to a wall. It’s very pretty.
Q. How hardy?
A. I believe up to Zone 5, most selections.
Q. That’s something I’ve never grown.
A. There are others in the climbing hydrangea family, like a Southern native called Decumaria barbara, or wood vamp. I really like it because it’s so much faster than Hydrangea petiolaris. The flowers aren’t quite as ornamental, but the foliage has this glossy ornamental almost-tropical look to it, and it grows very quickly.
Q. That is one thing about climbing hydrangea: It is slow to establish. I stand out there talking to it, saying, “Please, will you please grow this year? I’ve been so patient with you.” One day it finally does, but not till it’s good and ready. [Laughter.]
In a phone conversation or email sometime ago you said something that stuck in my head: That Clematis can be grown on supports in pots and overwintered that way with a little or a lot of protection, depending where you live. That they can become a perennial container plant and maybe then rolled back out into place year after year.
A. If you’re talking a tropical climate it’s a whole lot easier, and you don’t have to worry about freezing. Anywhere in the temperate climate you want to be careful with a couple of considerations. You want to size the container appropriately. I actually recommend if you’re going to leave them out, you use very large and very heavy containers, and if you can a very light-colored container. The biggest killer is that freeze-thaw cycle. They warm up in the sun, on a sunny day, and then freeze at night—over and over again, That’s just so brutal on roots.
If you’re going to take them in, that’s OK, but still size-appropriate pots, of course—I recommend large containers always. But if you have to go with a smaller pot, work with some of the compact hybrid vines. It’s a whole lot easier because you’re not struggling in the summertime to keep the properly irrigated and fertilized. If you’ve got a 2-gallon pot and a 20-foot-tall Clematis out there on your deck, you’re going to be watering it three times a day.
Q. I’ve been looking at your website—I love your plant finder, and I can search for different attributes. I notice that you’ve been raving about a new group of Clematis—the Riverside hybrids…
A. Passion flowers.
Q. Of course, passion flowers—I am hallucinating Clematis over here. [Laughter.] I haven’t grown many passion flowers, but what makes you rave so about them?
A. A number of years ago I met a gentleman who’s a breeder outside of London, named Myles Irvine. He has been hybridizing Passiflora for like two decades, and has done some really great work. [Above, the Riverside hybrid called ‘Damsel’s Delight.’]
He is a self-professed “vicious tosser.” If anything doesn’t come near to a high standard of performance, it goes on the compost pile.
Q. Off with its head!
A. Right. He’s been selectively breeding for a very long time, and has entrusted us to bring his hybrids to the United States. We working with a company called Plant Haven to introduce them as the Riverside hybrids. We have the first six of them out now.
What’s really great about them—it’s really all about his breeding program. He wastes no time with inferior hybrids, so the flowers are 50 percent bigger, and last longer, and there are more flowers per vine. The plants are vigorous and the plants are healthy—they’re overall superior.
You can’t really understand without seeing it in person, but if you take the difference between a 4-inch diameter and a 6-inch diameter flower, you say, “Oh, that’s only a little bit bigger.” But the impact that makes in the landscape is tremendous; it’s twice as much surface area.
Q. That’s a big flower for a Passiflora, and they’re so crazy-looking anyway, so exotic-looking.
A. They draw butterflies and other native pollinators.
Q. So not the Riverside Hybrid Clematis, which Margaret tried to rename them [laughter], but the Riverside Hybrid Passiflora. Thanks, Dan.
how to prune clematis
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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 March 14, 2016 show right here. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).
(Photos except Rex begonia vine and Dan at Trade Secrets provided by Brushwood Nursery, used by permission. Disclosure: A Way to Garden is proud to have Brushwood as a longtime friend and site sponsor.)