Gardening Unplugged - Evergreen Perennials

Gardening Unplugged - Evergreen Perennials

In this edition of Gardening Unplugged, recorded during our 2023 Winter Open Nursery and Garden Days, Tony Avent takes guests on a walk through the gardens and points out some of the evergreen perennials that are often underutilized in the winter garden. Learn how to add interest to your garden during the winter rather than just settling for dead leaves and mulch.

Evergreen perennials mentioned in this episode:

  • Asarum (Hexastylis, Wild Ginger)
  • Asarum kumageanum
  • Rohdea
  • Liriope
  • Saxifraga stolonifera
  • Ophiopogon (Mondo Grass)
  • Disporopsis (Evergreen Solomon’s Seal)
  • Disporopsis pernyi
  • Aspidistra (Cast Iron Plants)
  • Aspidistra elatior
  • Aspidistra oblanceifolia
  • Aspidistra ebianensis
  • Aspedistra linearifolia
  • Pyrosia (Tongue Ferns)
  • Cymbidium goeringii
  • Cyclamen
  • Chrysogonum
  • Cardamine
  • Dentaria
  • Dentaria diphylla
  • Ophiopogon (Black Mondo Grass)
  • Campanula poscharskyana ‘Camgood’
  • Carex
  • Carex oshimensis
  • Veronica officinalis
  • Geranium sanguineum
  • Sedum
  • Sedum emarginatum
  • Mahonia ‘Soft Caress’
  • Iris tectorum
  • Lycoris
  • Illicium
  • Illicium parviflorum 'Florida Sunshine'
  • Aspidistra elatior 'Snow Cap'

 

Video Transcription

So, we'll get started. All right, well I'm sure more people will join us. So, thank everybody for coming out today. We're going to do a short walk around and talk about evergreen perennials today. So, let's walk.

So, as we were just chatting, one of the reasons we do the winter open house is because we want people to realize that there actually is life in the winter. Most people's gardens in the winter, that we see, are pretty much brown mulch and there's so much more. We'll start with a couple of favorites; one is the wild gingers. This is the genus of Asarum. Some people in the South still stick with an old name hexastylis for the native things but these are quite incredible. There are deciduous and evergreen gingers, but these are one of the evergreens. This is one of the Asian ones; this is Asarum kumageanum. Right beside that is another plant, a first cousin to hostas, this is basically an evergreen version of a hosta and it's the genus Rohdea and you'll see a lot of those as we walk around today the Japanese really prize rohdeas because they have every kind of weird leaf form, variegated form, this is a little dwarf one that actually has variegation. The variegation will be much more pronounced later on in the year. Both of these are really good woodland perennials.

We'll pass a lot of ferns today and ferns that are evergreen, but evergreen doesn't mean they're going to look great all winter long so generally, by the end of the winter, the majority of the evergreen ferns could be cut back. So, we're just getting ready to go in, in the next couple weeks, and cut these back and let the new foliage look nice quite obscured, unobscured, by the old dead foliage. We've just done the same back here with the liriopes and mondo grass, both of which we're cutting now, and those are both evergreen and generally look good through the majority of the winter. The colder it gets and the more bad weather you get, the more hit they'll get in the wintertime but you don't want to cut them too early because, again, you want to embrace that winter foliage in the garden and you don't want to give them a reason to come up early. If you cut any evergreens back too early, more sun, more light hits them and they're likely to start growing early and then when you get a late spring frost that's never a good idea.

One of my favorites is the plant growing right at the base of the bamboo over here; this is an evergreen Solomon’s seal. And there are quite a few species of these now, I believe we're up to between six and eight, and these are of the genus Disporopsis the most winter hardy is one called D. pernyi, but you'll see quite a few of those around and they generally range, the tallest ones - two foot tall, the shortest ones - under a foot. And again, we will go in right before the new leaves come out, which is generally late March, and we will cut those to the ground and let them reflush. Not required for the plant, but just the appearance is better if you get rid of that one-year-old foliage.

Another plant that we do a lot of work with are the cast iron plants. And people from up North think of these all as house plants but, down here, the majority of them are actually pretty incredible in the garden. The heartiest – there’s three species that are the hardest of all - this is A. elatior, which is this one, A. oblanceifolia, and A. ebianensis. And we'll see the other ones in a little bit. But you get a little bit of damage, so this year we got to 11 (degrees F), you can see a little bit of browning on the foliage. The leaves on these generally stay for three years. At the end, after year two, they're going to start looking a little tired so every year we go in and clip the oldest years foliage and that keeps the plant looking nice. I know if you go in Southern gardens, you go down around Charleston or Savannah, you'll see clumps that look terrible and that's because they've never gone in and removed the three-year-old foliage. If you get a lot of that old foliage, you can go in cut the entire clump to the ground and start from scratch, but you want to do that in late spring because the new growth on these does not emerge until June. So, whatever you do, you don't want to cut them off too early then you you're left with nothing or a bunch of stubs.

Q: Will they grow back?

A: They will eventually but if you cut them too early…they're evergreen for a reason. They need to hold on to foliage and so if you cut that back in fall, it's going to be… it'll take a couple of years to come back. So, you want to cut it as close as you can to when that new foliage emerges. That's the key.

You see, as we walk through, many other ferns you see some of them come through in a little better shape than the others, but ferns are just such an important part of the winter garden because they add a very different texture than you normally find on many of your perennials. Now there are… it's a very interesting fern that we've been doing a little experiment about, and these are the tongue ferns. This belongs to the genus Pyrrosia these are epiphytic ferns. In the wild, in Asia where they grow, they grow hanging on trees. They do not grow in the ground. Now we can grow them in the ground, but where they love is in hanging baskets. So we got the idea several years ago, let's see if the baskets could stay out all winter long. So, these baskets went through 11 degrees (F) hanging right where they are. So instead of having to haul your ferns in for the wintertime, we think it's pretty neat. You'll see 17 different cultivars of pyrrosias all through the gardens and I think they look pretty amazingly good for having gone through 11 degrees so that's a great evergreen used in a different way.

[We’re] always looking for good ground covers and this is one of the absolute best. This is an Asian plant - this is Saxifraga stolonifera. It's sometimes called Mother of Thousands. It's sold as a house plant. It's absolutely hardy and what a wonderful ground cover this makes and look how good it looks having gone through the wintertime. Yes?

Q: Can this get any sun during the summertime?

A: It gets pretty shady. It really… you could give it a couple hours of sun; it would be fine. I don't think I would give it any more than that. And they have beautiful stalks… just each one will have a hundred white flowers. I mean it's absolutely incredible in bloom but what a neat way to, again, reduce the amount of mulch we need in the garden, and everything can come up through it which is really nice. So, we looked earlier at one rohdea, here's another rohdea, so you can just see the diversity within that genus.

Now we talked about the cast iron plant, so you know what cast iron looks like. This is also a cast iron plant, which doesn't look anything like the cast iron plants that most people know. This is Aspidistra linearifolia. So, when we started collecting aspidistras in 1980, there were only 16 named species. Nobody had really looked at aspidistras. Today, there's over 200 species of aspidistras and there've been almost 200 new species found since 1980. That's pretty hard to imagine. So, a lot of these things that we grow people just have never seen because they just haven't been out long enough.

So, here's the same thing growing side by side. This is the conventional cast iron plant; this is the new one we just showed you.

Now a couple of my favorite plants for evergreen… one, is this plant right here. And you look at it and you think – well, that looks like a liriope; in fact, it's not. This is an orchid. This is a cymbidium orchid. This is Cymbidium goeringii. This is one of the most incredible orchids, it doesn't look like anything that would be hardy. You typically think of orchids as no you got to have them inside but this thing blooms in February. It's pretty crazy so this is… we actually offer this occasionally, we don't have it every year, but what an amazingly fascinating plant.

Question?

Q: It's a scary question. I have variegated liriope and I just cut it all back…

A: Yeah, yeah, perfect, perfect. That's great, you're great, you're awesome.

Q: It looks like there is new growth.

A: It's ready to start. It's ready to start. This is…

Q: I'm seeing yours, I'm like wait a minute…

A: Yep, this is the time to do it.

And so here is another great plant; this is a Cyclamen. And the hardy cyclamen, another incredible plant. They need to be where it is dry. Do not put cyclamen where they'll get a lot of rain. They like it bone dry and they actually will go dormant in the middle of summer for about two months and for us they come back up in July and start flowering. So pretty incredible and very easy to grow. And you'll see more of the rohdeas, and we showed you some rohdeas earlier, here's some more. And not only do they have nice foliage, but they have these beautiful red berries through the wintertime, which I think is absolutely amazing.

Now you're coming by one of our best native ground covers, this evergreen. This is called "Green and Gold". This is the genus Chrysogonum and there are now four species of this. This has been in bloom since the end of January. That's pretty amazing for a ground cover and one that sadly a lot of people don't consider for their gardens.

And another plant that's not technically evergreen but it comes back up in fall is this plant. This is also a native, this is the native tooth wart. Tooth wart, it's the genus is Dentaria although some people now have lumped it into another genus Cardamine, but what a wonderful ground cover. This is just starting to bloom here in the next couple of weeks. This is Dentaria diphylla; d-i-p-h-y-l-l-a. I just… I love that in the winter garden. It's dormant in the summer so it's… I say it's evergreen; I'm sort of cheating a little bit because it's a… it does… but we have plenty of other things that are up in the summer, so we don't really need it in the summer. We do need it in the wintertime. In the winter, yes, it comes back up in fall.

So, we talked earlier a little about liriope and mondo grasses so here's some mondo grass here. This is the famous Black Mondo Grass. So, we will go in in the next couple weeks, whack that off at the ground, and it'll reflush very quickly. And then here, another clump of the rohdeas that we showed you earlier. This is more close to the typical species and not one of those crazy selections that they made but the beautiful red fruit is amazing.

Another group of plants that we think are pretty spectacular are the genus Arum. So, this thing here with the arrowroot, with the speckled leaves, this… arums are mostly Mediterranean plants and again, they go summer dormant, but they're evergreen through the winter. They come back up in September and they look great all the way through until late April when they go dormant, but they are really an amazing and very different texture in the garden.

And another odd group are the Ruscus. Now these are ruscus, we got a little bit of foliage damage this year, but they'll be fine. Ruscus are interesting in that they flower, see if I can find a flower, out of the middle of the leaf. And so, once the flower finishes on many of the ruscus, they form a beautiful red fruit. So ruscus are pretty fabulous and they're known for their tolerance for very deep, dry shade.

Q: Underneath the patio?

A: Underneath, yeah, they really take an incredible amount of drought.

Another couple of great evergreens, right here, this is called lungwort or Pulmonaria. This is a native to the Balkan regions and these do stay evergreen through the winter. Now they get looking a little ragged, so we've just gone in the last week pulled some of the old growth off and they're just beginning to flower. So, they have these bi-color flowers of blue and pink which we think is really quite nice. Another ground cover, right behind you, if you look at the small… let's see here, I'm going to step back between you right here. This is a really neat little Veronica. This is Veronica officinalis. Not really touted generally as a garden plant, but we find it absolutely amazing and that makes fairly large patches, little, short flowers, but a wonderful again, evergreen mat. We're just looking for anything that'll cover ground that's not called mulch in the wintertime.

It does get morning sun so this is… actually we just had a tree that died so, in another year, it will not get any more morning sun. But pulmonarias are pretty tolerant. They grow in very deep shade in the wild, but they actually have pretty good tolerance.

A lot of things that we've just cut, that would have been evergreen, are the carexes. Carexes are really neat group commonly called sedges. It's basically an ornamental grass that's a little on the smaller side. Some take shade, some take sun, but they're absolutely wonderful. You'll see the flowers on here they have really cute little flowers. We just love the carex. See if I can get you all a couple… so here's some carex flowers. They're again… they're not something that's showy. We call them very quaint, but I think they're really neat.

You see as you walk through another of those tongue fern hanging baskets. A little bit of foliage damage, but I think for 11 degrees, that's pretty darn amazing. Here's another lovely ground cover that I think is just superb. This is a campanula. It's a campanula with a terrible name Campanula poscharskyana. It's got a lot of letters in it but what an amazing ground cover. It doesn't take over, it's not a weedy ground cover, and it has beautiful blue flowers that will open up probably in another three four weeks.

Q: What’s the name of that campanula?

A: This is… this actually is an unnamed one but the one that's common that we sell is ‘Camgood’, c-a-m-g-o-o-d. Man, that plant is great.

So, we talked earlier about some carex. There are carex from literally all over the world. This is a Japanese one, this is a one of the many variegated carex and those came through the winter looking pretty darn good. We'll probably still clip those back just to make sure we don't have any dead foliage obscuring the new growth.

Q: How long does it take to get it back once you’ve cut it?

A: Just a matter of weeks. Yeah, really fast. Yes, question?

Q: Should you wait till about June to cut it back?

A: No, these start reflushing almost immediately so I would cut them right now. The things that don't reflush to June would be really your aspidistras. That's really the main one that doesn't come back early. Most everything else reflushes really fast. Question? yes

Q: [Question about spreading carex]

A: No, you… well there are spreading carex and there are clumping carex. This is a clump one. These have probably been in there a decade. Now, if you ever want to divide one of the clumping carexes, do it in the winter. If you divide it any other time of year, it will die. Carex are really funny about that so yeah, you divide that you can divide it in in summertime, you'll get 100 and 99 of them will die and you're back to your original one. So, wintertime.

You see more of them over here, same carex. You see how that's used. They're absolutely lovely plants and there are many different variegated forms. We've got another different one around the agave here. They just add a very different texture so they're very good to soften a bowl texture in the garden.

Q: What level of shade tolerance do they have?

A: They prefer shade actually. Well, it depends on the carex. This is Carex oshimensis. That really is a shade plant. We've sort of experimented. We were told that, that's a gold one, would not take any sun so we do a lot of experiments. If we if we know something takes shade, we're going to plant it in sun. We always do the opposite because for us, it's not about being successful as much as it is about learning something we don't know. So, we make… we've killed more plants than you can possibly dream of. Last check, our computer said we killed over 50,000 different kinds of plants, but… (Congratulations) thank you, but we've learned something so we can then… when we propagate the plants say, “this does not work” and we say that from a point of actually having tried it.

Another great evergreen; this is Geranium sanguineum. A wonderful little geranium. Again, nice ground cover. Needs a little more sun not particularly shade tolerant.

And again, we talked yesterday… we did one of these about hellebores so I won't get into great detail, but obviously you can see an amazing array of hellebores scattered. Another great evergreen, Sedum, is this right here. This is Sedum emarginatum, a fascinating little sedum. Again, very different texture, so we've got a lot of options for evergreen plants in the garden, and you'll see a lot more. I'm going to stop here because I know I [have] way overrun my time but please enjoy the gardens. We'll be here to answer any questions. If you have any more while we're here please… yes.

Q: The mahonia that got hit, what’s your prognosis?

A: They'll be fine. ‘Soft Caress’ is probably one of the least hearty mahonias we grow. It will actually re-sprout and be fine.

Q: On the same stalk?

A: It should.

Q: Or should I wait until April before cutting…

A: I would wait. There's no point. There's nothing to be gained out now because we could still have some cold and anytime you cut, you're starting to force new growth and so with, you know, our last frost is generally April 10th around here. Yeah, I'd wait on that see what the damage is. I just got back from Atlanta last weekend and got to see the original ‘Soft Caress’, which was selected by a friend of ours, and they got five, and it really looks ugly. So, it appeared that the stems are okay, but we won't know for sure till a little later, so I'd wait. Great question. Yes?

Q: Can you point me in the direction of a garden that you have around here that only gets afternoon sun like from 1 to 7 PM? Do you have anything like that?

A: We do. Let me… just it's going to be easier for me to point you to…. that's West.

Q: Okay.

A: That's West so anything that you have you would see West because it really does vary on what side of the beds you're on. That would be North. So, the West sun is where your most extensive… you know, your heat is going to come. So, this area where we are right here gets blasted by West sun in the afternoons. So, sun, it really does matter. I mean your general… we classify shade or light into four categories; you've got sun or full sun, as we call it, you’ve got part sun, which means generally you get less than six hours a day of sun. So, one to six. Then you've got light shade, which means you never get any direct sun, but you can actually see blotches of sun on the ground. And then full shade, which means you never see any sign of sun on the ground. And so, as long as you understand those are your four conditions, you can better site your plants. So, we've… everything that we offer in the nursery we will say full sun to light shade and that gives you the range of conditions. But do understand those. When you're in shade, light shade always allows you to grow more plants than full shade, always. So, what we do, is where we have trees, is we are raising up the canopy. And a good example would be down here if you see these pines. So, about six, seven years ago, stuff in here just started going backwards. It just was not growing. So, we came in, got us a really tall pole saw, and we started cutting off the lower limbs, so we didn't have to remove any trees but were able to lift the canopy. Because the more layers of branches that the light has to go through, the less light is going to get to the floor. So, it's a very simple way without having to get a chainsaw in to lift that canopy and all of a sudden plants came back. I mean within two months. The growth rate is amazing on plants so don't hesitate to get you a long pole saw, and I'm not talking about the crap they sell at the box stores, those saws are worthless. You want to buy a real saw, something like a Haytai saw, h-a-y-t-a-I, those are well balanced. You can get them to over 20 feet. They're really incredibly easy to use. Sorry, I went off on a tangent there. Any other questions? (We like your tangents) Okay, sorry about that. Yeah, there's a… if you're into really saws, like I am, there's a company called Silky Saws on the Internet that is amazing. They carry a lot of the real high quality Japanese saws and the Japanese have really got saws down. I mean, they're more cool saws than you can imagine. They're just so much different than the stuff you buy at the box stores that you cut a couple times and the blades break. They're just… it's just a big difference - silkysaws.com.

Q: It’s really good to see your ferns here, because I bought that one.

A: Oh, the cycads here?

Q: Mine is looking like that and I thought it died.

A: No, all the cycads, you can see the big one right up there by the corner of the house, they will always lose their foliage. Anything below about 16 degrees, but they're fine. Now, we will not cut them back yet because it takes four weeks for the new growth to come out and so we will time back from April 10th, last frost date, March 10th, these get cut. Because you don't want that new growth coming out in the middle of winter. So, people that are neat freaks wind up actually hurting their plants by cutting them back way too early.

Q: And that’s Iris ensata?

A: Right here? This is Iris tectorum down here; this is a roof Iris and that's semi-evergreen. And you see a lot… we've passed a lot of these today, these are surprise lilies or hurricane lilies if you're from Louisiana. These are the genus Lycoris, and these are quite amazing. Now there's some that come out in the fall, and you have this wonderful evergreen foliage in the winter and others that don't come up until March. So, it's again, another option for getting that texture in the garden this winter is to use the fall emerging lycoris. Other questions? Yes?

Q: That banana tree over there, what version is that?

A: The banana tree over here? We have a… oh the Illicium right here. This is Illicium parviflorum 'Florida Sunshine'. That's actually our introduction. That's an amazing plant for adding color into the winter garden. If you don't know the plant, go over there, and pick a leaf and crush it and smell it. It's wonderful. It's a Southeast native, normally comes in green, but what an incredible plant that is.

Q: Where would a snow-capped aspidistra be in the garden?

A: Let's see, probably in the front garden. If you go out in the other side of the greenhouses, there should be several clumps. Go out in the front there's a little rock garden on the other side of the waterfall, in the front, and it's right in there, right under a big pine tree.

 Okay, thank you all very much. Okay, thank you, thank you. You're welcome.
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