IN MY QUEST for a wider plant palette and for ideas on how to put plants together with a confident, bolder hand, I asked Director of Horticulture Louis Bauer of Wave Hill, the renown garden in New York City that has been long praised for its dramatic plantsmanship, for advice. Whenever I visit a public garden, I see irresistible plants that are new to me and wonder how the horticulturists behind such designs, like Louis and his team, find all these goodies and figure out how to use them so spectacularly.

We talked about the advantages of growing from seed, about extra-cooperative little plants like certain sedges and Erigeron (fleabane) that can beautify even tough spots like at the roots of trees, about using pots to announce garden areas and the signature plants of each of the distinct gardens at Wave Hill, too—like larkspur, to name one.

the plants of wave hill, with louis bauer

Q. Glad to have you on the show, Louis.

A. Thanks for asking me.

Q. Thank you for saying yes because I need a little help with my plantsmanship over here. [Laughter.] So for people who haven’t visited Wave Hill, which is a must stop for any keen gardener, do you want to just give us the teeny version of why we need to come visit—a little bit about Wave Hill?

A. Well it really is a plantsman’s garden, you alluded to that. It is a garden about plants that has grown very organically on the grounds of a very old estate, but it was remade over the past 50 years, starting with Marco Stufano, who was here for a very long time and had a very small budget. And I think that got us started with seeds.

Q. Ah, and so the trick of plants that could be grown from seeds.

A. They are pretty cheap if you do it right. But now we have greenhouses and they are a little expensive, but we still grow a lot of things from seeds for lots of different reasons.

Q. Yes, and it’s right on the Hudson, facing the Palisades across the river in New Jersey. So it has dramatic views as well, doesn’t it?

A. It does, and interesting terrain. It’s called Wave Hill because the first people who moved here from Manhattan, which is just a few miles away, came here to get away from the urban environment. And viewing the property from the river, it looks like the crest of a wave, sort of lots of up and downs.

But we’re on the crest of that wave and we look across the vast Hudson to the cliffs across the river, but have lots of microclimates. So not only is it a nice getaway from the city, but we’re packed with little microclimates that really increase the kind of variety of things we can grow.

Q. So you have different gardens within the garden, and a team of gardeners who I presume some of them care for one area or another most of all or something.

A. That’s right.

Q. And so when it’s time to order plants, and especially seeds, and decide what to grow this coming year, it’s not just one person like me and my home garden with the seed catalogs. I can order whatever I want or not. I don’t have to discuss it with anybody. It’s a dictatorship. [Laughter.] But yours must be quite the process to decide what to order. Maybe it’s like the voting in states that have caucuses. Does everybody try to try to convince everybody else what we’re going to grow or how does it work?

A. I’ll tell you how it works and this may surprise you. [Laughter.] I’m a gentle overlord when it comes to ordering the seeds. They’re real squabbles come when the seeds germinate and we need space to grow them on. So it’s easy to have a very long list of things you want to grow. It’s another thing to find space when they’re all coming up. So I tend to be pretty generous when people are ordering 20 or 30 different kinds of things to try. And if we were only growing three of each, it would be easy.

But obviously we have a big garden, and sometimes we need 40 or 70 or 100 of something, and that makes sense to grow from seed when you need so many. But sometimes we’re growing things from seed just to try out half a dozen plants. That’s where the real juggling comes. Also, the price of seeds doesn’t tend to add up quite so fast as nursery plants.

Q. [Laughter.] That’s for sure.

A. It is easy to overindulge. And so honestly, the squabbling comes for space in the greenhouse at the end of March and April.

Q. O.K. So because you shared with me the spreadsheet that you all made, which was color-coded and all kinds of organized and everything.

A. Everybody’s initials.

Q. Yes, yes, yes. Who ordered what and so forth and where it came from. So it was quite a list. It sounds like you guys start a lot of things from seed. Is that kind of your preference? Besides the economics of it, is that something that you love to do?

A. I started at Wave Hill as manager of the Tropical House. So growing things from cuttings was my thing.

Q. Oh, O.K.

A. There are a few things that we still put in the Tropical House to germinate, even though most things germinate at about the same temperature. There are a few things that like the extra warmth in the Tropical House, but I always appreciated some of the reasons to grow from seed and that was the subtle variations that you get from growing some of things from seed and we can talk about that later. But some of the people who joined our team in the past 10 years had a great reputation as seed growers.

Q. I see.

A. And they, I think, increased the number of things that we grew from seeds in the past 15 years. There are some groups that have always been grown from seed, especially alpines and natives, but we expanded that in the last 10 years.

Q. O.K. So the fight for greenhouse space is going to be even wilder than ever.

A. [Laughter.] It is.

Q. So your personal, if I remember correctly, your educational background, I think there may have been studying of architecture?

A. That’s right.

Q. And I seem to also recall maybe around the time we first met, I almost feel like you had a stint working with floral design maybe?

A. Floral design and graphics.

Q. Yep. So a lot of influences. So when Louis Bauer looks at catalogs, what are you looking for, to wade through? Because there’s a lot out there. What are you looking for? Like what types of plants or categories of plants? What catches your eye?

A. Well, it’s so many things, and it’s not easy to say what it is exactly. And this is going to sound contradictory, but partly it helps to know what I can get from nurseries and what I am going to have to grow from seed.

Q. I see. So necessity is one thing. O.K.

A. So if I want yellow or blue violas, I know I can get them at the local nursery. And if I want marigolds or those kinds of things. That’s kind of a long list…

Q. Commodity items.

A. …but I get around so I know what people are going to have for sale. But some of the .things that are most important here, and I’m thinking of them at this time of year, are the early spring things that we put on display while the weather is still pretty cold.

We grow a lot of wildflowers and display them in the Palm House with South African bulbs. And like violas and calendulas, there is another dozen things that we grow because we have to grow them from seed, because there aren’t that many people out there who want these things that are really the early cool-season things.

Q. Right. So the nurseries in New York City area aren’t doing a big business in early April probably.

A. So some of the wildflowers are Nemesia, and Heliophila, and Calceolaria, and Mimulus—pretty little wildflowers that gardeners in the West grow in the cool weather, the same as the violas that everybody likes in the spring. So we have to grow all of those from seed. We can’t buy them.

Q. I see. Do you look in the catalogs? Do you have a passion for, say, is it something new, or is it something old? Do you have any niches that will always attract your attention?

A. Frankly, it’s more often things that are old.

Q. O.K. So?

A. Species hostas, species daylilies. You would think that with 15,000-something daylilies and maybe even more hostas that, who in their right mind would bother to grow them from seed? But believe it or not, counter-intuitively, but I’m interested. We’ve been growing some Hemerocallis thunbergii, one of the species daylilies, and what’s wonderful about them is that they’re really simple and graceful, and they have a slight variation in color. Some are pale yellow and some are really gold and some are almost melon-colored. And that is just a natural variation. And especially in places like the Wild Garden, it just makes them look like they belong there in the Wild Garden part of Wave Hill.

Q. How long does it take from seed to grow that daylily?

A. About two years.

Q. About two years.

A. The first year they get a little longer growing season because we’re growing them in a protected place, and some of them have bloomed in the second year.

Q. Oh. So it’s an investment of time.

A. Yes, but it’s not a huge investment. We’ve grown lilies from seed, too, and they take three or four.

Q. That daylily, is it big, is it small? What’s it like?

A. H. thunbergii has a nice tall stem but not a very big flower. Like I said, I think what’s wonderful about it is its gracefulness. It kind of bobs in the air, and it doesn’t have a big mushy ending. When it’s faded, it kind of drops off on its own. It is simple and graceful. I’m repeating myself. [Laughter.]

Q. No, that’s O.K. Was it something that used to be available more? You know what I mean? Is it something old?

A. I think probably a hundred years ago it was available, but now that there are 15,000 named ones, the nurserymen trip over themselves trying to have the newest one that no one has. And I don’t know, maybe someday the market will change a little and there will be a resurgence of interest in simpler things. I think that’s really what it is.

Q. And you’ve told me in the past that you kind of like simple and old-fashioned things, things that, like you just were saying, as opposed to the 15,000 or 50,000 or whatever that are out there that are all new, perfect, whatever, improved, the latest thing.

A. Big, fat, ruffly. [Laughter.]

Q. Yes, yes, yes. I saw on the list, on the spreadsheet, some sort of things that I think of is kind of old-fashioned perennials, some Dianthus, for instance, some Digitalis. Can we talk about those a little bit? Those to me feel like from an English garden a little bit, and I don’t mean to say you’re copying English gardens, I don’t mean that at all. [Above, Digitalis and Allium in the Flower Garden.]

A. But you’re right. They were popular in English gardens and some of them work well in our gardens, too. And there certainly is a place for plants that have been selected because they performed better in our weather.

But some of the street species are just wonderful. And the reason that nursery businesses have moved away from them is that in some ways a lot of the nurseries have become big business, and the only way they can sort of protect their rights over merchandise is to have a named form that’s trademarked.

Q. Right.

A. And so they have a hard time marketing the simple, straight, old-fashioned things. There’s no marketing mechanism behind it, so it doesn’t get attention to grab the consumer’s attention.

Q. So the little Dianthus, for instance, I think of those as something I expect to see at Wave Hill, not masses everywhere or whatever, but-

A. Little patches at the front of the beds.

Q. That’s what I was going to say. At Wave Hill, the plants aren’t obedient to stay within the confines of the bed. They’re happy to cascade over, and that’s part of the softness against the hardness of the path you’re walking on or something.

A. That’s true in most places, but as you said at the beginning, we have a number of different gardens that make up our Wave Hill’s garden. How we manage those gardens differ a little from area to area, but we definitely have more places where they creep over the edge. And we like that, especially as the season goes on, to get a little looser.

Q. Yes. Another thing I saw quite a number of, different varieties were Eryngium on your list. Is there some Eryngium obsession going on at Wave Hill at the moment?

A. I think maybe Harnek [Singh] in the Flower Garden is a little Eryngium-obsessed, but Gelene [Scarborough] tries to keep up with him in the Wild Garden.

Q. And you’re referring to two of your gardeners, two of your team.

A. Yes, two of the team. Gardening can be competitive, too, you know?

Q. So what do you think about Eryngium because it’s more and more people that I know are growing it again. I remember couple decades ago, we all were excited about maybe one or two that were out there, but it seems like there are more.

A. There are more, and not just from seed because there are a few new species that are available as you look at some of the specialty seed catalogs, but there are also some new selections that are a little bluer or there’s even one with gold foliage [‘Neptune’s Gold’].

Q. Oh my goodness. You’re kidding me. [Laughter.] That must be crazy.

A. It’s a tough one to grow, but in the Wild Garden especially, we stick to the straight species. And so I think Eryngium bourgatii might be the one species you saw on the list that hasn’t been around for a while and suddenly it’s on seed lists. So we have to try it.

Q. So as people who don’t know, eryngiums are sometimes called sea hollies, I think. Is that the common name?

A. That’s right.

Q. Yes, and then there’s that silvery one called rattlesnake master that’s not called a sea holly, but I think that’s Eryngium yuccifolium, which I love as well.

A. Yes, native ones? And a biennial one with ‘Miss Willmott’s Ghost.’

Q. ‘Miss Willmott’s Ghost,’ which used to be a thing in English gardens; I remember that was sort of a signature plant. Another sort of English garden thing I had never seen it in an American garden, but years ago I saw it in England and now I saw on your list was Centranthus ruber, I think, the Jupiter’s beard. But you didn’t order a pink-flowered variety.

A. No, a white one. That has for decades been a plant that was in between the greenhouses that became the Herb Garden, then the Dry Garden. These were old greenhouse foundations that became little garden rooms and they had spaces between them that were kind of .. well anyway, in-between spaces. [Laughter.] It’s a tough old-fashioned perennial that comes in a kind of pale brick color, but there’s a white form, which is very nice. And I think in the process of doing some renovations, we lost the clumps that were there, and are looking to get them back.

Q. O.K. So putting everything together is the hardest part. It’s one thing to say “I’ve got this and I got this and I got this.” One of the ways that we put things together is with what we kind of semi-jokingly called filler plants, right? Plants that help things come together. And do you have some of those that you’re kind of excited about or using more or whatever on your list this year?

A. I have two that are kind of on the top of my list and they are things that especially help to fill in in dry shade. Erigeron pulchellus, which is fleabane. [Above.]

Q. Fleabane, yes.

A. It doesn’t have a very appealing common name, but it’s a wonderful plant on tough tree root zones.

Q. And is this a version with a different size flower or something?

A. Actually, its flower is kind of simple. What’s nice about it is its leaf. It has a broader thicker textured leaf.

Q. But it’s like a tiny little daisy-ish looking thing. Yes?

A. Flower is a little daisy, and kind of simple, and I’d be O.K. if it didn’t bloom at all.

Q. Oh, that’s interesting.

A. Because it looks like a velvety Bergenia.

Q. Oh, O.K.

A. Its leaf is that thick and flattened against the ground. And I’ve been been trying it in a couple of places combined with some of the Carex that tolerate dry places, like Carex appalachica.

Q. Oh, so that’s a native sedges, the Carex appalachica.

A. Yes. So it’s this fine-textured little tuft that looks like grass, and a flat velvety leaf. So the combination of textures is wonderful and fill up places where I can’t get very many different things to grow. But those two are very happy and it makes a segue into the part of the woodland or tree underplanting where I can grow some interesting things. So they are definitely fillers for spots like that.

Q. For that transition-y kind of area.

A. Exactly. In our Native Plant Garden, there are a couple of other Carex like Carex grayi that has an interesting little seed head. So we’ve been growing a number of sedges. That’s probably not news. Carex have so many hundreds of species that we barely know that fill all sorts of niches in the garden and pull things together.

Q. And it’s really becoming more of an “it plant” in the sense of, it was almost unknown not so long ago, other than a sedge here or there in a native setting.

A. Or some Asian one with gold stripes.

Q. [Laughter.] Right.

A. Those gaudy ones. [Laughter.]

Q. Yes, we don’t want those.

A. We’ve been growing some from seed, and in our woodland where we have trouble with some invasives filling up the empty space, getting Carex to grow in some of those in-between places helps to knit things together and keep the garlic cress or the stilt grass from getting a foothold.

Q. The naughty beasts.

A. Exactly.

Q. So with pots, is there a color theme in each area? I don’t mean to make it sound formulaic, but… So we talked about how the garden faces out to the Hudson River and part of the view is through a beautiful old pergola structure, and there are frequently pots arranged there very artfully. Is there like: “This year we’re doing everything there in pink and silver and blue”? Do you see what I mean?

A. Yes.

Q. There is? O.K.

A. Yes, in fact the gardeners each … There are several areas where things are very thoughtfully color-schemed: the entrance to the greenhouses and the center of the Flower Garden [above] are two places where there are groups of pots. The pergola that you mentioned, which kind of frames the view out to the Hudson, and the terrace where the café refreshments are served and people sit there for awhile. All of those areas, the gardeners put a lot of thought into how the color combinations will work together.

So each year there is a little shift in silver and blue with touches of gold, or reds and purples and fuchsia. And sometimes it’s more than one scheme. It’s one scheme in the spring and then when we changed over to the hot-season plantings, it’s a different scheme. So yes, there are. Jen likes to make a little color board with clippings pasted on a board, her little menu of plants going out. Other people just keep a list of the names and they picture them in their head. So everybody has their own way.

Q. So that was a good tip, though, that in areas where you’re sort of announcing that you’re arriving at something, like the entrance to the conservatories or the flower garden or looking across to or being drawn to the pergola, that it’s important to have it more planned and more together. So that’s a good tip.

We just have a couple of minutes and I just want to ask you sort of rapid-fire, if I said: “I can’t imagine Wave Hill without, dot, dot, dot,” are there signature plants that you feel like are synonymous with Wave Hill?

A. Without woad in the Wild Garden.

Q. [Laughter.] O.K., woad.

A. It’s that huge cloud of chartreuse yellow flowers that is a plant that was used to make indigo dye. In the Flower Garden, I would say I can’t imagine the flower garden without larkspur [above] and poppies [top of page].

Q. Yes.

A. I can’t imagine our little native Elliptical Garden without Zizia, which is golden Alexanders. Each garden, I guess maybe deserves its own “can’t live without.”

Q. Interesting. Yes, I know. I completely agree. So is the woad, I’m going to guess from the depths of my old rattled brain, Isatis tinctoria. [Important note: This plant is invasive in some regions of the U.S., including the Intermountain West and Northern California.]

A. Yes.

Q. Isatis tinctoria, right? [below.]

A. You got it. [Laughter.]

Q. It’s a dye. Right, with the dyer’s woad. Yes. Oh, those are goods ones. And you just said larkspur,, didn’t you in the flower garden?

A. Yes.

Q. Does that sow itself every year or do you have to redo it?

A. It sows itself, but every once in a while we try to introduce … We have from time to time introduced a new shade of larkspur. We also conscientiously decide which ones to save for self seeding so that there are just a few pink ones and mostly blue.

Q. I see. So you edit a little. Yes.

A. There’s also a kind of smoky gray-blue one that we tried to get going and sometimes have to add a few seeds because it seems to shrink.

Q. Well, Louis Bauer, I love all of these ideas and I’m going to give visiting information and everything else about how people can find Wave Hill. So thank you so much for making the time and sharing the ideas.

A. You’re very welcome. My pleasure.

more from wave hill

• Visiting Wave Hill
• Upcoming events (for gardeners, families, and lovers of the arts)
• The gardeners’ blog at WaveHill.org