extend your clematis bloom season to spring through fall, with dan long
DO YOU HAVE CLEMATIS blooming in your garden from early spring to late fall—or does that sound like a worthy goal? By selecting the right varieties and also knowing how to care for one that can be coaxed into longer, more robust bloom, it’s possible.
When I’m plant shopping, I try to discipline myself by reciting a little mantra: “early, middle, late.” As in: It’s a long season of possibilities, if you plan correctly. Early, middle, late is the reminder to fill my garden-center wagon (or my online shopping cart) with more than a single moment of a favorite plants, and enjoy a prolonged season.
You might already be following that advice with lilacs or daffodils or daylilies and have not just one variety but a whole sequence, but we can—and should—be doing it with Clematis, too.
My vine-mad friend Dan Long of Brushwood Nursery, longtime clematis specialists, gave me a lesson on how to really stretch the clematis season in our gardens with a winning strategy that combines proper plant selection, pruning, feeding, vigilant watering and more. Turns out some of the Clematis I am already growing could be putting out more blooms over more months using Dan’s tips, too.
Read along as you listen to the April 3, 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).
q&a on a long season of clematis bloom, with dan long
Q. I know you are in the Athens, Georgia, area—Zone 8ish?
A. They claimed we moved from 7B to 8A, and this past winter I would believe it. But we still do get some really cold temperatures, down to 7 or 8 degrees Fahrenheit.
Q. So from the first Clematis bloom there to the last, what’s your potential Clematis season, with all the possibilities?
A. We have some that have already bloomed in March—like the new Sugar Sweet hybrids, and the montana types, though we are really at the hot end for growing most montanas. They don’t like hot summers; most of them don’t live very long here. And then we go all the way up into November, with a few of them covering many of those months.
Q. So you are talking like nine months or so of Clematis potentially for you where you are. How many clematis do you have in your collection at last count? You are a madman I know. [Laughter.]
A. [Laughter.] We probably have over 400 different varieties here.
Q. Oh, my goodness. So with the idea that we will stretch the season and move through the progression, what are some of the ones that we can stretch the season with, back into early, early spring?
Then you get into the alpinas and montanas, and the macropetalas—all very early blooming Type 1 species and hybrids. Even up North, they can start in April. [Below, a macropetala called ‘Lagoon,’ and a montana called ‘Natalie Cottrell.’]
Q. And then do we get into the main event—the ones that people are most familiar with?
A. Right, and they are called the large-flowered hybrids, and they are late spring into early summer. There is a really wide range of genetics in there, so they’re often divided within the early, middle and late large-flowered hybrids. But they are all what we would call late spring.
Q. I think for many people those are what’s synonymous with Clematis; they look the most familiar. Let’s go through the rest of the bloom sequence first, then double back to those—because I think those have more potential than I am aware of. I could do better with them in my garden.
What’s blooming next in summer?
A. Beginning even at the end of what we would call the large-flowered hybrid season, you get into a lot of terrific plants that I think are underappreciated. The first would be the viticella hybrids, and they don’t have as massive a flower each. Some of the large-flowered hybrids will get 8 or even 10 inches across each, but these are smaller. But they are really prolific in bloom and very easy to grow.
For folks who are maybe a little concerned or have had difficulty with large-flowered hybrids in the past, I think the viticellas are a great starting point.
Q. Name a few of them; I think I have some and don’t even know they are viticellas.
A. ‘Etoile Violette’ [above left] is one; ‘Madame Julia Correvon,’ ‘Purpurea Plena Elegans’[above right]—those are some of the ones that are primarily in that group that you might find in a garden center. There are so many more: ‘Solina’ [right photo second from top of page] is one that I think is underappreciated but fantastic.
Q. What color is ‘Solina’?
A. It’s a pale blue; it reminds me of ‘Perle d’Azur,’ but it’s a lot more vigorous and easier to grow. ‘Burning Love’ is a wonderful rich red that’s a newer hybrid. ‘White Magic’ we have just gotten a hold of and hope to have out next year. But there are literally dozens and dozens with the genetics.
Q. If we want to keep extending past the early Sugar Sweet types, and past the large-flowered hybrids, and maybe with a little more ease of growing the viticellas…
A. And there are others, like the integrifolia group and its hybrids. Integrifolia is a herbaceous perennial, not a climber. It will get up to maybe 3 feet, and is typically blue, but there are some white selections and fuchsia-colored, and pink ones. ‘Floris V’ is one of my favorites of those. [Above left to right: integrifolia and ‘Floris V.’]
In addition to that, there are hybrids with integrifolia, and because integrifolia can bloom all season long, they’re bringing those genetics in and making climbers and what we call scramblers—semi-climbers. Probably the best-known one would be durandii, which is blue. It’s a scrambler.
And then ’Arabella’ [left photo at second from top of page] which I have to say is my single favorite variety to recommend to anyone anywhere. It grows all over the country, blooms all summer long. It’s a scrambler that you can use as a groundcover, and you can put one in the perennial border. It just goes and goes; it’s a really generous plant.
Q. And what color is it?
A. It’s a pale blue. And there are a lot of other integrifolia hybrids out there now. Wim Snoeijer in the Netherlands has been breeding those, and he has a River Series—‘Star River,’ ‘Mississippi River’ and a few others—which are very nice.
Q. So then we extend farther, though in some cases we’ve been going all summer long. It’s funny, there is that Clematis called the sweet autumn clematis, that I don’t think behaves very well, does it? [Laughter.] But we think of fall and it pops into people’s minds—but it’s not the only choice for the latest end of the season.
I used to grow Clematis tangutica [below left], which recently met an untimely death after many, many years of performance—a yellow-flowered one that was sort of a fall bloomer.
A. It is, late summer and into fall—and again, it depends on your climate, and whether you get freezes early that slow it down. We no longer offer sweet autumn, because one year I was driving through the Heinz Wildlife Refuge and it was blooming everywhere—and it is invasive and displacing native flora. We need to avoid that one.
Q. Are there others that are late with that frothy white thing going on?
A. Clematis virginiana [above right], a native, is another small white flower, and it is pretty. It’s a little more of a coarse texture. It doesn’t have that sweet fragrance as much; it has a light fragrance. It is considered the native alternative to sweet autumn, but it’s not a superstar like that but it’s native and not invasive, and we need to be responsible in our plantings.
Q. Others that don’t get started till late?
A. You mentioned tangutica, but it’s not just that one species. There is the orientalis group, and even a white-flowered hybrid with tangutica in it called ‘Anita,’ which is a sweet little plant. The thing about those: You do have to be careful because they will succumb to poor drainage; that’s often their demise.
Q. Oh. [Laughter.] You must have read the mind of my clematis. I had this plant many years and its was monstrously big, and wonderful. We had a funny late winter where the area where it was got puddles and pooled and there was ice underneath; a number of things in that area died. That’s death to many things, to have wet feet in the cold. The poor thing couldn’t rebound.
Even beyond just choosing varieties: I was looking through your catalog online, and I was wondering what I could do to extend my season. I have one area where there is a big hedge of evergreens, and I thought it would look great to have towers of vines set off against the evergreens late in the season. So I was going through, and when I found some that I do already grow and have big, old plants of, I realized I don’t think I am getting the most out of them.
Like I have a ‘Duchess of Albany’ [below left]—what group is she in?
A. It’s a texensis hybrid, another really great one for a long season of bloom.
Q. Some years she is covered, and some not; and I don’t get a long season of bloom. What’s up with that? I don’t think I am being the best Clematis parent I could be. [Laughter.] Can we talk about that and the aftercare of some that could bloom longer if treated properly?
A. Sure. Good, steady fertility is important, and a lot of time the ground dries out in the summer. They won’t die from that, but they won’t give you optimum performance. Clematis are never going to be xeric plants—like succulents or cactus.
Q. [Laughter.] Not for the dry garden.
A. The roots run deep, so they’re not going to perish—but they won’t perform. Good, steady fertilizer through the season; I ‘m a big fan of the Espoma products. Rose-tone is a formula that works very well for Clematis.
Q. I never would have known which one to choose.
A. Rose fertilizers in general tend to have a good formula for Clematis. There is no “Clematis-tone,” at least not yet. And that will help; continuing to feed will help.
Q. When do I feed?
A. We’re on old cotton land down here, so I feed and feed and feed. I like to give a good topdressing of compost annually, and I will topdress Espoma Rose-tone throughout the season for the ones that continue to give. I would hesitate to make a single recommendation of how often and how much, because everyone’s soil is different.
Q. But you’re talking about keeping up with it, and also with the watering—that’s super-important.
A. The ground really will dry out, especially if you have a significant planting that’s dense with flowers.
Another thing you can do—and this is a big thing that a lot of folks miss with the large-flowered hybrids—they have that big, powerful, cover-the-entire-vine bloom going on in their main season, and then they can look kind of ratty.
Some folks report that they look ratty all season long, and what are they going to do with that? This is a great opportunity here: Go ahead and cut them back, by a third or a half, and give them a good shot of fertilizer and a good shot of water. This is after that first season of bloom has really waned. Go ahead and hack them back; you’re not going to kill them. They are going to be fine, and actually will enjoy that water and fertilizer. Some of them are capable of reblooming right away—jackmanii for example [purple booms in photo above right]. I know somebody with a fairly long season who actually does this three times, and gets three full solid flushes of bloom per year.
Q. That’s being greedy. [Laughter.]
Q. To ask them to bloom not once, not twice, but three times.
A. It takes work, but you’re like me: an active gardener. You don’t put something in the ground and walk away, and look at it from a distance. You’re out there working with your plants; you’re enjoying being with them. To do those extra steps, the plant will reward you with more.
Q. I think I haven’t really been thinking about how much drier and generally warmer things have been here. I asked you at the beginning about your Zone, and you said it looks like you have fallen into 8a, and I am supposedly 5b. But it feels like we’re having a lot of extended dry periods in the growing season, and I think maybe I am not responding.
This is probably a problem for gardeners everywhere, who are used to responding to seasonal signals and the signals have changed. I haven’t gotten with the program, and am not remembering to water—like last year , we had no rain for three and a half weeks. No wonder the ‘Duchess of Albany’ decided to sulk. I should know better, but I am not in the swing of the “new normal” yet.
A. I’ve become a really big fan of drip irrigation.
Q. That’s what I was thinking when you were saying this, and because you have such a large collection.
So we will be more vigilant about feeding, and watering, and with the large-flowered hybrids if they look like hell, we’ll cut them back by a third or half and feed and water them again and give them TLC.
What other ones do you want to tell us about that either need special care or are good investments for extending the season?
A. In a similar family to the sweet autumn, if you really miss that but know you shouldn’t be planting it, there is the Clematis recta ‘Purpurea.’ It’s a double-bonus plant—a tall, scrambly herbaceous perennial, but it has lovely deep rich-purple newer foliage. It does green out over time, but the best selections have really rich color, and then it’s topped with lightly fragrant, starry-white flowers.
Q. I have a plant that I bought for the old Heronswood Nursery, that came to me with its roots in a sandwich bag—no bigger than a wholesale nursery liner or “plug”. It’s called ‘Lime Close,’ and it’s now this massive shrub-sized thing. When it comes up, it’s like these hundreds of the darkest purple fingers coming out of the ground [above detail], and then comes that froth. I also have plain recta, which has no purple to it. They are great, you’re right.
The only thing I would say is I don’t know how to prop it up any more, it’s so big.
A. It does get a bit gangly over time, and it depends where you plant it and what you want to do with it—like if you grow it between mid-sized shrubs so it’s all propped up on its own. There are some folks who just love that foliage, and the foliage color is what they are shooting for. As the older foliage greens out they will cut it back, and fertilizer and water it.
Q. And let it push again. That makes sense. It is a beauty. Any other treasures?
A. I recommend to take a look at some of the newer hybrids, coming out of the breeding program of Raymond Evison. He’s working with large-flowered hybrids, but they are capable of blooming all season. Look at ‘Rebecca’ [below right], a fine sample of a long bloomer. He named it for one of his daughters.
Q. He’s in England, yes?
Q. And as you said, the genetics they’re picking up on include the inclination to repeat or continuous bloom.
A. He’s working with compact habit, long steady bloom, in large-flowered hybrids. A personal favorite of mine is ‘Starfish’ [above left]. It was bred by Polly Hill on Martha’s Vineyard, and we’ve had that in bloom for six months straight, which is pretty surprising for a large-flowered hybrid.
Q. What color?
A. It’s pure white.
Q. Six months? That’s amazing.
more from dan long
- How to prune all 3 categories of Clematis
- Vines off the trellis: creative use of climbers
- Browse the Brushwood website
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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 April 3, 2017 show right here. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).
(Disclosure: Brushwood Nursery, where I have shopped for years for my own garden, is an occasional sponsor of A Way to Garden. Photos except C. recta purpurea ‘Lime Close’ all courtesy of Brushwood; used with permission.)