growing baptisia, with george coombs of mt. cuba center
IF YOU’RE NOT GROWING Baptisia, why not? Its credentials are impeccable: Baptisia are native to the United States, drought tolerant, deer resistant, and have not just great flowers (in a choice of tempting colors) but beautiful foliage, too. In fact, this perennial looks good from the moment its stems first emerge from underground in April-ish right through to its showy, late-season seedpods.
Plus, various butterflies use the foliage as their host plant, and bumblebees find the flowers particularly delightful.
George Coombs of Mt. Cuba Center in Delaware is one gardener who has not overlooked baptisias, the so-called false indigos, at all.
In fact, he has planted and evaluated 46 selections with genetics from 11 different species as part of the trials conducted at Mt. Cuba from 2012 to 2015, and when the full-color report on those side-by-side assessments arrived recently in my mailbox from George (you can read the pdf version here online), I knew it was time to welcome him back to my public-radio program and podcast to talk about the best of these great plants.
Read along as you listen to the Aug. 22, 2016 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).
my baptisia q&a with mt. cuba’s george coombs
Q. What are you trialing now out there, George? I’ve gotten the Baptisia report, but what’s in the ground now?
A. We’re actually about ready to take out our Baptisia trial, and are about ready to install a trial of Hydrangea arborescens. We’ve got about 30 different kind of smooth hydrangeas we’re going to test. And we’re just wrapping up our Monarda trials; we’re just in the last weeks of that.
That report will be coming out in December, and we’re slated to replace that with a trial on sneezeweed, or Helenium.
Q. Oh, that will be nice.
A. I don’t know much about those plants, so I’m looking forward to that one.
Q. And I can look forward to my Christmas present from you this year, which will be the Monarda report.
A. We’re also in the middle of our Phlox trial. The Phlox are looking a little worse for the wear considering the weather we’ve had recently.
Q. [Laughter.] Margaret is looking a little worse for the wear, George.
A. I think we all are over the past couple of weeks. In that trial it’s exciting to see what’s doing well, or well-ish.
Q. Well-ish; that’s a good one. I like it.
I remember a few years ago, doing a story with Tony Avent of Plant Delight Nursery that he called “Plants in Need of a Good PR Person,” and Tony named Baptisia as one such plant. Tony, who is a Southerner as his accent would give away, in case people don’t know him, calls Baptisia his “red-neck lupines.” [Laughter.]
Why have they been so sort of overlooked or hidden? Why haven’t they been front and center as perennials that everyone needs to grow?
A. I think maybe the first strike against them was the fact that they were native plants. For a long time people weren’t really interest in native plants, but were more interested in things that were exotic, or hard to find.
As we’ve broken down that barrier a little bit, I think the main reason why people aren’t picking these plants up is that they don’t look good at a garden center in a nursery pot. They’re usually pretty slow-growing plants, at least from the beginning, so what you usually see is a 1-gallon or 2-gallon pot with two or three stems. Maybe there’s a flower; maybe there’s not.
It’s not exactly screaming, “Pick me up off the shelf; take me home.” You have to know what the plant’s going to turn into to really shell out money for it.
Q. It doesn’t show its little head off in the garden center—and actually I think you probably agree with me: I am sick of plants that show off in the garden center and then don’t turn out to be great garden performers, long lives, and good traits in my real-life garden.
A. Exactly. We test a lot of plants here at Mt. Cuba Center, and they breed and select to look good in a pot. But then in a garden setting, they don’t hold up to that expectation. The Baptisia is kind of the opposite; they don’t look good in the beginning, but they just get better and better and better.
Q. [Laughter.] You have to have a label on them that says, “Trust me; I’m going to be gorgeous.] Now when I say Baptisia, it’s not just one species, is it?
A. There are actually several species, and I would say most of the plants you would encounter in a garden center are actually hybrids of those species. You might run into Baptisia alba, the white-flowered species [below], or Baptisia australis, the blue-flowered one, but other than that in most case you will see hybrids in yellow, blue, white and colors in between.
Q. How did they get from overlooked to where they are now? Who got behind them—propagators or breeders or…?
A. People really started t pay attention to them in the 1990s. A couple of hybrids were found as happenstance at the North Carolina Botanic Garden: ‘Purple Smoke,’ which is still sold today and is quite popular and a good performer, and did quite well in our trial, and ‘Carolina Moonlight’ [below]. They were really new hybrids that combined the best of a couple of different species. That really brought people’s attention to, hey, maybe there is more to these plants than we thought.
Also, the fact that it was new and exciting, it naturally brings attention to plants.
At the same time, the Chicago Botanic Garden was working on a formal breeding program there, and they had released two of their first cultivars in the mid-2000s.
Since then, the steam and attention has been picking up—though that’s among avid gardeners and people in the know, the hard-core crowd. The average gardener is still in the dark about how nice these plants are.
Q. Was Walters Gardens another place that was working on them?
A. Yes, they’re a more recent breeder, but the Chicago Botanic Garden has probably been the most prolific up until now. Now we’re seeing cultivars come out of Plant Delights Nursery, from Tony Avent who you mentioned, and from Walters Gardens, which is a big wholesale operation in Michigan. They have a good breeding program in-house, and they’ve been working on Baptisia with a few new cultivars that they’re bred for more compact flower habits and more flower colors.
Q. There are many different species and they’re native to the Eastern half or two-thirds of the U.S.?
A. Yes, some of them have different ranges. Some are just found in the Midwest, and some are more Eastern plants, but almost all of the species are found from the Rocky Mountains eastward. So they’re very much used to the temperate climate that we have.
Q. They really range in size, and also in flower color. You mentioned white, blue…
A. Yellow is the other predominant flower color. When most people think of Baptisia they think of blue, but that’s actually the least typical color that you would see among the various species. Yellow is probably the most common, followed by white.
They range in habitat. Some are sand-dune types of plants that you wouldn’t see growing in a heavy clay soil like we have around here. Others are more Midwestern prairie plants that you might see in a grassland situation.
But they’re really resilient plant—that’s kind of the thing that most gardeners find so great about them. They’re so hard to kill.
A. A lot of that comes from the fact that they are legumes. They have a symbiotic relationship with bacteria in the soil that allows them to pull Nitrogen from the atmosphere and turn it into fertilizer for them. In return, the bacteria get sugars from the plant.
Having that beneficial relationship lets Baptisia thrive in difficult areas where other plants would struggle. They’re very much adaptable plants to a lot of different situations. Even though you might have a plant that is growing in a grassland prairie, it works just as well in a garden setting. They’re super-tough plants.
Q. Maybe we can go through some standouts. They may have subtle differences beyond this is a blue one or this is a yellow one. As I mentioned in the introduction, when they’re coming out of the ground certain varieties are very dramatic, or later on the seedpods. What were the different traits you were looking for in the trials? Was it good garden size—an appropriate size—or what were you looking for?
A. We tried not to put personal taste on top of what does well. Our rankings were based on how vigorous they were, and how floriferous—how many flowers and for how long were they blooming. Over all, just foliage quality and flower quality.
A lot of plants that did poorly in our trial were ones that either didn’t put out a lot of flowers or they actually had pretty floppy habits. That was something that I didn’t really expect within the trial. I hadn’t had too much experience with Baptisia being floppy. But there were several newer cultivars and a few species that disappointed us in that way.
One of the things that surprised me how much I appreciated it: As the stems are emerging from the ground [below left; seedpods in right photo], it’s early spring and you wouldn’t think there is a whole lot there. But a lot of them are quite attractive because they develop a dark purple or gray color to them. Usually that color will persist as the stems elongated, though it fades a little bit, but you still get some color there. The darker the stem color is in the beginning, the darker it will be when they are flowering. So some of the yellow and white flowers have gray stems when they are in bloom, so it’s a nice contrast that really sets off the flowers.
Q. One of my little obsessions are plants that emerge not just green—that come up out of the ground in the spring full of other kinds of pigments. Like I’m thinking of blue cohosh, Caulophyllum, or twinleaf, Jeffersonia—two native plants—they come out of ground with not chlorophyll but anthocyanins, the other pigments, showing. I love that because at that time you have this blank canvas, and can really notice things like that.
Plus with the Baptisia, the structure—there is something elegant about them.
A. Even the green ones are pretty. When you’re looking at 50 of them [in the trials] the standouts are the ones with dark stems. But it’s almost an artistic emergence from the ground, and they grow quickly so it’s a fleeting display you can only appreciate for a few weeks in the spring, then they grow into their normal habit. It’s almost as interesting as they full display, because it’s so fleeting.
Q. And of course at that time of year we’re all crawling around cleaning up the beds, so it’s a good viewpoint to see them. [Laughter.]
What were some you particularly liked, some highpoints of the trials?
A. One of my favorites was probably ‘Lemon Meringue’ [above right, beside B. australis in the trials]. It’s a nice medium color; it wasn’t too highlighter yellow, or too pale.
Q. “Highlighter yellow.” [Laughter.]
A. It’s a kind of Goldilocks yellow and I feel like it works well in the garden design. One of the things that I like about ‘Lemon Meringue’ is that it’s a very vigorous cultivar in terms of how quickly it grew to a mature size, but it wasn’t so vigorous that it became this mammoth plant. A lot of Baptisia plants, especially some of the earlier cultivars, grew to be quite large—bigger than many people want in their garden. ‘Lemon Meringue’ is a nice medium-sized plant that fits well into most landscapes.
In that vein, as far as going against the bigger ones, there was ‘Ivory Towers’ and ‘Blue Towers.’ They’re basically the same plant but one has white and the other blue flowers, obviously. The reason I really like these two cultivars is that they have a really nice vase-shaped habit. I think a lot of times when we’re breeding for small plants that fit into a garden setting, they just get shorter.
Q. They can get squat, can’t they?
A. Yes, and a lot of times that doesn’t look great—or at least you can’t have all your plants looking that way. ‘Ivory Towers’ and ‘Blue Towers’ are nice because they’re tall and slender, so you get a large plant without giving it a lot of real estate to occupy. And they have what I would call naked stems, so for much of the height of the plant it’s just bare stems. It’s a graceful silhouette that you see, rather than this round, blocky, leafy shrub-like thing.
Q. And that’s a perennial where it would be a shame to hide those “legs,” so to speak. It would be nice to let them show.
A. And early in the spring—most of these plants are blooming right around Mother’s Day—other things are still small. So you can plant around them and still appreciate them when they look their best, and then let other things fill in.
Q. ‘Ivory Towers’ and ‘Blue Towers’—again, that word elegant comes to mind.
A. Those are actually two from Plant Delights Nursery, and he’s breeding for that slender habit, and long, taller flowers. A lot of his plants cultivars have a similar look to them.
Tony explained that to me, and where at Walters Gardens they’ve been working to enhance color—everybody have their thing in breeding.
A. Yes, everybody picks an avenue and specializes.
Q. But Tony said he wanted separation between the flowers and the foliage—more like a lupine, in a sense.
A. That was one thing that was surprising to me. I know just from hearing about and talking about Baptisia, a lot of people would wax poetic about the fruit. But with a lot of the cultivars, their foliage would continue to grow even after they’re flowering, so the foliage would overtake the inflorescences. So with the fruit, you wouldn’t see it—you’d have to dig around inside the plant.
Q. So it wasn’t the showy seedpod ornamental trait, because it was hidden in those cultivars.
A. They’re still great for taking inside and using in dried arrangements, but not something that you would appreciate in the garden so much. So he’s trying to get a taller inflorescence so that even as the foliage grows, you’re still going to have some fruit to look at above the leaves.
Q. You mentioned a white one, blue one, yellow one…but some aren’t those colors at all. Like ‘Cherries Jubilee’ [above] made the trials report.
A. It’s the closest to what you could call read, and it’s called ‘Cherries Jubilee,’ but it’s really more of an orange color. What’s really interesting about it is that the buds open more of a dark maroon, and they slowly fade or become lighter, more of an orange-brownish. So depending how you’re viewing the plant, at what stage in its bloom, it looks very different.
I always have told people this hasn’t been my personal favorite plant. When you view it from a distance, it tends to look a little rusty-brown, but when you’re up close to it, it’s so striking and so different—you can really appreciate the color gradation from the bud form right down to the fully open flower on each inflorescence. It’s definitely a striking color, and in terms of being new and exciting, it’s at the top of the list.
I think they are working now toward pink colors, and bicolor flowers. I’d expect to see as we go into the future some even more exciting flower colors.
Q. There are some with the word chocolate in their names, like I think the report includes ‘Dutch Chocolate.’
A. That was the best of those chocolatey-brown colors that all look very similar. But ‘Dutch Chocolate’ is really nice because it has taller inflorescences and a compact habit, and it was more sturdy and reliable in its garden performance.
Q. I’ve seen pictures of the trials at Mt. Cuba, and when I think, “What looks good with Baptisia?” I think, “More of them!” [Laughter.] Because the trial looked gorgeous. When were they blooming, and was it over a number of weeks?
A. They usually start for us around the 10th of May, and last until the end of May. Certain ones are a little earlier, but most last about two or three weeks, if it’s cool. But that’s our window here.
Q. So other than having 46 cultivars in one garden, as you did in the trials [above], what role do you think they play in a bed design or in a naturalistic planting. What would you put them with, or where would you use them?
A. I think I would use them more as anchor plants in the landscape—more towards the back and maybe at the corner of the bed. If it’s the foundation of your house, I’d use them more at the corner and plant around them. I wouldn’t necessarily use them in mass, unless you have a huge space to fill, which would be a great use.
But in terms of Baptisia, less is more. I like the idea of having one plant be almost a focal point in the garden.
Q. They really have stature, don’t they?
A. When they’re in bloom, it’s hard to look at anything else. They’re so incredibly colorful and the blooms are so bright and attractive. It’s just something you’re going to want to have attention drawn toward. The rest of the year, I think, they’re very nice foliage plants—great filler, and background plants. So you’re going to want to have other things around them to draw your attention.
Q. Are there others we should have a look at? With some, the dark color goes all the way up the stem. Tell me about those.
A. There is one called ‘Crème de Menthe’ [above left, beside ‘Dutch Chocolate’]. That was the darkest gray-stemmed cultivar. What’s really nice about that one is that even when the stems emerge it’s the darkest, and it stays relatively the darkest, even when it’s in bloom. ‘Crème de Menthe’ has a pale gray flower, so it looks really sharp against the dark gray; it’s a classy combination.
Q. Do you deadhead them, or let the seedpods form?
A. We usually let them form; I don’t think it does any benefit to deadhead them. In most cases, the flowers themselves fall off pretty regularly. So it’s not something where you deadhead because it’s unsightly petals hanging there. Those fall off pretty quickly.
Q. Full sun?
A. Full sun, and they’re pretty drought-tolerant once established, but you want to make sure that they get some water to get going. They can take a little bit of shade, particularly Baptisia alba is tolerant of partial shade. But in most cases, you’re going to want to put them in full sun. They’ll get more energy and flower better in full sun.
more from mt. cuba and george coombs
- Best heucheras with George Coombs
- All the trial garden research reports
- Using natives in a formal border at Mt. Cuba
- Visiting Mt. Cuba Center in Delaware
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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 Aug. 22, 2016 show right here. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).
(Photos courtesy of Mt. Cuba Center.)