THE PHRASE “native plant garden” probably conjures an image of a spring woodland of trilliums and other little gems, or perhaps a meadow blooming from high summer-into-fall, loaded with asters, goldenrods—and butterflies. But a recent announcement from one of America’s great native plant landscapes, Mt. Cuba Center in Delaware, got me thinking otherwise.

It got me thinking formal.

The Mt. Cuba press release described the redesign of a formal garden originally created in the 1940s to complement the estate’s impressive Colonial Revival home (one that’s now on the National Register).  And the photos looked inspired by a proper English-style mixed border–except the headline and captions all made it clear: the new plant palette is native-only. Delphiniums need not apply, apparently.

Surprising, and exciting.

I invited Mt. Cuba Director of Horticulture Travis Beck, one of the team that created the new formal native garden, to join me to talk about using American plants in less-expected places in our gardens. Read along as you listen to the June 27, 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).

About midway through the interview, learn what goes into selecting perennials for a formal border—what qualities the gardeners sought—and some great, mounding native front-of-border choices for spring and summer.

my q&a on native perennials with travis beck

Q. Before we talk about the redone formal garden, Travis, let’s give people a quick picture of the Mt. Cuba landscape and a little background.  This was an estate in the du Pont family, I believe.

A. That’s right. This was the home of Mr. and Mrs. Lammot du Pont Copeland. Mr. Copeland was an executive in the DuPont Corporation in the mid-20th century, and so they did quite well for themselves. They invested a substantial portion of their money in the creation of a lovely country home, in the Brandywine region of northern Delaware, and pretty early on had an inclination that they would like to open this property to the public someday.

Mrs. Copeland in particular was involved in the 60s and 80s on in the creation of naturalistic gardens here. We have as a whole 582 acres at Mt. Cuba Center, much of which is in natural land. But within that we have a 50-acre or so area of landscaped grounds, and within that is 20-some acres of gardens, which include naturalistic gardens as well as an area of formal gardens surrounding the house.

Q. And it really did catch my eye, when the press release came the other day—especially the pictures. It’s adjacent to the house, this National Register Colonial home built in the 1930s, I believe.

A. Correct; between 1935 and 1937.

Q. This South Garden is on the south side of the house, I presume. What did it look like before?

A. The original design was done by Marian Coffin, who did a number of landscapes in this area, including pieces of the Winterthur property, and parts of the University of Delaware campus. So when the Copelands were looking for someone to do the next phase of garden development post-World War II, they reached out to her.

She designed the formal layout of this area, including the brick walls, the brick walkways, and this area—the South Garden—is adjacent to a pool in a Maltese cross design, that we call the Round Garden. [Above, plants ready for installation in the new border, with the former Copeland home behind.]

Q. It’s quite the thing—a walled garden, with this Maltese cross-shaped pool at its axis.

A. And that was once the family swimming pool.

Q. Oh my goodness. [Laughter.]

A. So it has quite this symmetrical layout, and there are allees of trees above and below this area, so it’s very much a very formal garden area.

Q. So unlike many other areas of Mt. Cuba, where you might walk in what feels like a woodland with slight human intervention, or a beautiful water area that’s naturalistic and expansive—this is much more strict.

A. Absolutely.

Q. So what were the plants before? Were there like tulips and delphiniums?

A. We have had tulips and delphiniums in the Round Garden. In the South Garden, in Marian Coffin’s original design as she worked it out with the Copelands, was a combination of Ghent and Exbury hybrid azaleas in a color progression from a bright yellow to a burnt orange or almost red at the other end. These were combined with things like climbing roses, Sarcococca lining the edge—and other interplantings were done as well. And then in the lawn there were some boxwoods, and I believe a crabapple tree at one point in time.

That had gone by the wayside by the time I arrived here in 2013, and what was in place then was a very valiant attempt to reinterpret that original design using all native azaleas.

Q. So goodbye Exbury hybrids and hello flame azaleas (Rhododendron calendulaceum)?

A. Exactly, and collections had been made and cuttings done so that the color progression was still in evidence, but the plants themselves were really struggling. Part of that had to do with replacing the upper allee of trees that had been shading a portion of the garden. When that was removed suddenly, this area being on the south side of the house with these brick walls became a full-sun environment.

Q. Toasty. [Laughter.]

A. Yes, toasty. The first year I was here, we had to replace 14 azaleas along both sides of the garden. They weren’t thriving, and it wasn’t the sort of display we hoped to have. And it was hard to make the case that it was serving our mission of exciting the public about the beauty and value of native plants.

Q. So we come to today—or not today, since with you and your colleagues, a lot of planting went into this. So this is the first season when the newly redone South Garden is ready for primetime.

You’re describing a formal area near a grand home, that’s hot and sunny—not exactly like out in the wild. When I browse the catalogs or websites of the noted native plant nurseries, I see plants categorized for purposes like make a “butterfly garden” or “hummingbird garden” or “rain garden” or “meadow” or “woodland garden. “ But I don’t see ones listed to make a “formal mixed border.” How in the world did you figure it out?

A. I had the benefit of working with two of my colleagues here: Donna Wiley, who is the gardener for our formal gardens, and Victor Piatt, who is our gardens manager, and formerly managed the cut-flower garden for the Copeland family.

So both of them are very experienced gardeners, and know not only what it says in the catalogs, but in the years they’ve been growing these plants. So the three of us sat down and began the process of developing the plant list for this garden, and thinking what were the great plants we really thought would fit our criteria.

Q. What does one look for? It does feel a little English-inspired mixed border—and I don’t mean that as copy-cattish or anything—but just to conjure a visual image for people.

A. And I’m happy to hear you say that, because that’s very much the design intent we were going for.

Q. And that’s contextual to the place.

A. Not even a contemporary interpretation of that, but a somewhat familiar version.

Q. Which works with the house, and the walls, and all that.

What kind of plants did you right away say, “Ah, we’re looking for this or that,” or what were you thinking of replacing in that classical English border? Like in the introduction I said delphiniums. Were you thinking we need vertical stuff for the back of the border, and succession of color, and mounding stuff for the front, and mid-level things?

A. You could have designed this garden, Margaret. [Laughter.]

Q. I’m in charge of all this stuff; I’ll be right down to fix it right up. [Laughter.] No, not if you saw my informal place you would not say that.

A. Those were many of the things we were thinking about. Because we had a double border on either side of a walkway, we wanted to have plants that people could look at and not feel overwhelmed by.

We have the walls on both sides that range from 2 feet to at their very tallest 6 feet in height. So that sort of set the framework for the heights of the plants we wanted—we wanted to stage down from the height of the wall to more of a pathway height.

We needed plants that performed, ad looked good in foliage as well as in flower. They didn’t necessarily have to have a super-long season of bloom, but they needed to fit into our overall bloom sequence in a very precise way.

We needed to know that they were going to thrive in the conditions we were putting them into. We said from the beginning: There’s not going to be any staking in this garden; we can’t handle that. We’ll figure out to what extent we’ll do deadheading and cutbacks as the garden matures. We’re not planning on fertilizing, and we really don’t want to water.

Q. Well, you are some tough cookies over there at Mt. Cuba. [Laughter.] Actually, that’s exactly how I feel about plants, and all good stuff to consider.

A. And one other great resource I should mention that we were able to make use of were the results of Mt. Cuba’s own trial garden. [All the trial garden research reports are archived here.]

Q. Your colleague George Coombs has been a guest a couple of times, and told us about them. I would think that was great on-site, real-time insight for you on what works and doesn’t there.

A. We pulled from some of our previous trial-garden reports, like on the coneflowers and the asters. Both coneflowers that were used in the garden were top performers in the trials here, and one of the asters was a top performer. The other is actually a Mt. Cuba introduction, the ‘Bluebird’ smooth aster.

Beyond the material that has already been formalized in reports, we had access to George, and his photos that he’d taken. So we could really precisely time the bloom sequence of things, by looking at his photographic records—saying, “We really need a Penstemon that’s going to fit in this window.”

[Get PDFs of the Mt. Cuba coneflower research, and their aster research.]

Q. Did you have a color palette in mind?

A. Donna was the one who came up with the original idea of really basing the color palette on the bricks that are used in the walls. They’re basically a reddish brick, but they have a variety of hues in them—including a purplish hue—and then we’ve got a little bit of lichen on the walls, which introduced some silver tones. So this became our color there, of having the purple-bronze foliage as well as some silver foliage, and then obviously green as well.

We wanted the color progression to change throughout the year, so it wasn’t one thing the whole time. So we intentionally started a little bit soft and slow in the spring. There is plenty to look at at Mt. Cuba in the springtime already, with our ephemeral displays, so we just start off with a little bit of Iris verna blooming in a blue color, and then we start to bring in some pinks and yellows. And then it really begins to pick up about now, as we’re getting the purple of Tradescantia and the Liatris and then we’re soon going to have some oranges from our Lilium superbum [above] and butterfly weed—a little more intense version of that purple and orange.

Q. So instead of orange Oriental poppies in an English garden, or something else that would be orange, you picked two natives.

A. We didn’t do a 1-to-1 substitution, but tried to work with the plants with the best qualities that we had, and create something that had that character of the English garden.

One thing we were very mindful of is that in a full-sun situation, many of the plants that you could draw from are meadow plants and we didn’t want this to look meadow-y.  We have just one grass in there, the Shenandoah Panicum, so we wanted it to have that perennial- or mixed-border look to it.

Q. Front-of-the-border kind of mounding, lower stuff that comes down to pavement level?

A. We’ve got the iris that I mentioned as one of our lower edging plants. We also have a great little catchfly or Silene called ‘Short and Sweet.’ It’s an early pink bloomer that fits into that spring palette, and when flowering is only 12 inches tall’ the foliage is lower than that.

We also found a nice blanket flower [Gaillardia, above] and the cultivar is ‘Arizona Apricot,’ and that’s one of our path edgers as well.

Q. So later in the season, with things like goldenrod—or you also mentioned an aster before—one doesn’t want the coarsest version we see along the roadside. We want something a little more refined. Correct?

A. So there we chose the ‘October Skies’ as one of our asters, which has a relatively mounding habit, and then one of Mt. Cuba’s introductions [get pdf of all introductions], the ‘Golden Fleece’ goldenrod, which stays in the sort of 24-inch height and has nice basal foliage throughout the season. [Left, ‘Golden Fleece.’]

Q. A lot of the Solidago, the goldenrods, can be a little thuggish in nature—is it the Canada one that is especially that way? Is this better behaved?

A. This has exploded in the garden but so far in a very good way.

Q. “Exploded”–that’s a very interesting word, Travis. [Laughter.]

A. It has filled in quite well, and that’s one of the things we will be watching as things develop. Obviously something like the butterfly weed is going to take awhile to get up and going. We’re monitoring all those edges.

I don’t mean to give the impression that the ‘Golden Fleece’ goldenrod is anywhere near the danger that, say, Canada goldenrod is, but it’s definitely a happy garden plant.

Q. And a friend—someone you probably know, Marco Stufano formerly of Wave Hill—says: “Margaret, who has the shovel, you or the plant?” If I say something is too ambitious, he says, “Who has the shovel?” And I say, “OK, OK, I’ll edit it; I’ll fix it.”

A. And we’re very excited to see how everything works out. We’ve obviously done our best research and thinking in putting the design together, but it all waits to see how it performs in reality. That’s the fun project we have before us now: watching the garden come in, and seeing how everything does.

Q. Let’s talk about wildlife interactions—are you expecting pollinators and such, or are you seeing any, as you do in the more naturalistic areas of the garden?

A. This is one of the most wonderful things about planting this garden, because as I said it hadn’t been performing well prior to the redesign. It felt like just kind of an emptier, quieter area in the gardens. Within days of planting the garden last fall, I saw bumblebees cruising through the area, and we actually had monarch. That was just very reaffirming.

We hadn’t designed the garden for pollinators in any particular way, researching what insects would interact with what plants, but we certainly loaded it up with native flowers, and the wildlife seems to be responding.

Q. Interesting. So it’s an all-native redesign of a formal garden—and I read that you’ll be teaching a class called “The Mixed Perennial Border” on July 8.

Are there favorite plants you are glad got into the design, or that you’re excited to see come into their own?

A. One that we included at the last minute, in sort of a revision just before the plants were ordered, was the giant coneflower, Rudbeckia maxima.

Q. Oh, yes.

A. We said, “Let’s put a little drama in here,” and we’re getting drama already. The flower stalks are up above my head.

Q. Already? Wow.

A. And the large elephant ears are showing. I’m excited to have that plant in the garden, and think it was a good last-minute addition.

visit mt. cuba; take a class

MT. CUBA CENTER in Hockessin, Delaware, is open to the public April through October from 10 AM to 4 PM, Wednesdays through Sundays. A range of classes and symposiums are also held at the 582-acre botanical garden focused on native plants and ecosystems, whose mission is to inspire an appreciation for the beauty and value of natives and a commitment to protect the habitats that sustain them. Browse the Mt. Cuba calendar.

Travis Beck is giving his mixed border design class on July 8, from 10:30 to noon. Details on that class.

Make an outing of it: Mt. Cuba is about an hour’s drive from Chanticleer Garden, perhaps 20 minutes from Longwood Gardens, and similarly close to Winterthur Museum, Garden and Library.

prefer the podcast version of the show?

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 June 27, 2016 show right here. You can subscribe to all future editions on iTunes or Stitcher (and browse my archive of podcasts here).