Gardening Unplugged - Gardening with Evergreen Perennials

Gardening Unplugged - Gardening with Evergreen Perennials

with Tony Avent

By Published August 2022

In this episode of Gardening Unplugged, Tony walks through the garden and discusses the variety of evergreen perennials available at Plant Delights to add interest to the winter garden. Gardening Unplugged is our series of free classes presented by JLBG/PDN staff during the Garden and Nursery Open House days. These are 15 - 30 minute discussions walking through the gardens, focusing on seasonally prominent topics, plants and garden design ideas. This episode was recorded during our winter open house in February 2017.

Evergreen perennials featured in this talk:

 

Video Transcription

Today we’ll be talking about evergreen perennials. I’ll begin by trying to explain what an evergreen perennial is. Because, as with anything, humans trying to classify nature doesn’t always work. We have things that are green all year, we have things that are green all winter and go dormant in the summer. So, are they evergreen or are they just winter green? Then we have things; are they a perennial or not? Because that line between perennials and shrubs is really blurry. Some of the things I’ll show you today, they’re evergreen but you could argue either side of where they’re perennials. So, let’s just start looking at a few.

Adding Interest to the Garden in Winter

The reason we use evergreen perennials is so the garden has interest in winter. Because anybody can do a garden that looks good in Spring. That takes no ability whatsoever gardening wise (laughter from audience) I mean, it doesn’t. It’s really simple. Wintertime is when you really have to know the plant and find things of great interest then.

One of my favorite plants is this… this is a plant called butcher’s broom or ruscus. It’s a European native. It has generally male or female. We do have several, and I’ll show you some as we walk through, that have both male and female and when they do, they have red berries on it all winter. This is probably the most shade tolerant plant that exists. You could grow this under a deck. (laughter) There are not many plants that will grow where that grows. Love the ruscus. This is also first cousin to a plant many of you may know called Poet’s Laurel or Danae, used in flower arrangements. Another that I would an evergreen perennial. This is actually, the closest plant to this is asparagus that we eat (laughter). Yes, believe it or not, it’s basically an evergreen type of asparagus. When the new shoots come up, you can actually see that they look like little asparagus.

Alright, other plants that we don’t normally think of would be - stokes’ aster, stokesia. One of our great native plants. And in the wild actually grows with pitcher plants. People don’t know that. It likes it really soggy but yet will take very dry. So just texturally, I find it very interesting, even though it doesn’t have any blooms in the winter months.

Now, we talked about things that die down and then come up. And a classic example … (bird chirping) hello. A classic example would be the surprise lilies or lycoris. There are two types, there’s the type that the leaves come up in October and the type that the leaves come up in February.  And so, these will actually go dormant in the late spring, early summer but they look great in the wintertime. So even though they are not technically an evergreen perennial, you can certainly use them in the same way you would [use evergreen perennials].

Is it a Shrub or is it a Perennial?

Another really great favorite, and this is a particularly dwarf one, these are called sarcococcas. Now that’s one of those you can say - Is it a shrub or is it a perennial? I call them perennials. This is actually a first cousin to boxwoods. That’s the mature size of that. They’re just coming into bloom now, and hopefully we’ll take you to some that are in full bloom now. Extremely fragrant. You can find sarcococcas that get three foot tall, you can find them that get one foot tall. They are completely evergreen all year and have wonderful fragrance. There’s really not much like it. Again, for very dark shaded areas, absolutely fantastic.

Another great one that I think deserves a lot wider use are rohdeas. A rohdea is first cousin to a hosta. And again, completely evergreen. We’ve just finished harvesting the fruit but just like the ruscus, it has beautiful red berries that are on it all through the wintertime. And again, very tolerant of shade. It will take some dry shade, but it really prefers some moisture to do its best. The Japanese have been collecting these for years. There are probably 200 to 250 named varieties in Japan with all kinds of little funny variegations on them.

Hellebores, the Picture of Winter Perennials

And obviously, today we’re going to be looking at hellebores. Hellebores are probably the picture of winter perennials because they do have leaves that persist through the winter. Now we will come through here and we cut all the leaves off about a week to two weeks ago. Just because the leaves get tattered in the wintertime. We will leave them on long enough to slow them down. What we want is… we don’t want them to flower this early. This is way too early. So, we will leave the leaves on. Once the flowers are up above the leaves, there’s no point in keeping the leaves on any longer so then we snip the leaves off for more of a show. And these are all European natives, well primarily European natives, just really nice evergreen foliage.

(Comment from audience member about the noise) Yeah, we’re redoing a lot of stuff. It’s amazing what happens during the wintertime when we’re not looking (chuckles from audience).

Aspidistra for Dry Shade

Now one other group that I think are particularly nice are the cast iron plants or aspidistra. There are many different types, some hardier than others. This particular one gets a little bit of winter burn for us but really nice foliage. And this, you can see, is a form of Aspidistra elatior that has almost no damage on it. And again, for dry shade, just absolutely fantastic plant. Now a plant many people may not know or may not recognize is this … looks like a grass. (Incorrect guess from audience member) No, that’s also an aspidistra. It doesn’t look anything like the plant behind you, but yet it is. And this is really interesting how nature has plants that look like something else. So, take a look at that, and take a look at that plant over there. They look just alike, don’t they? That little grassy plant over there, almost identical. Okay, that’s an aspidistra, that’s an orchid. That’s actually a hardy cymbidium orchid which are absolutely amazing. If you see those for sale, we offer them occasionally, not every year. These actually flower in another couple of weeks they’re actually in bud now. That’s a Cymbidium goeringii. That’s the only hardy cymbidium orchid. So, there is a lot of things to give you this wonderful effect from the aspidistras to the orchids or some of the little carrot grasses.

Another group that is really nice that I think deserves a lot wider use are the evergreen bamboos. These are the clumping bamboos. I do not ever encourage anyone to grow the running bamboos which are incredibly problematic. You’ll see a lot of these as you walk through the gardens today. They give you a wonderful textural interest in the garden that is really not available on anything else, especially in the wintertime.

A nice little groundcover here would be something like the saxifraga. This is a, well it’s got a lot of native cousins, this is a Chinese version. A lot of people grow this as a house plant, they call it strawberry begonia. It’s not related to begonias at all, I don’t know how it got that name, but a beautiful evergreen groundcover. It does spread but not invasively, this patch is well over ten years old.

Try Cyclamen in the Worst Conditions

Another excellent one for evergreen foliage are the cyclamen. Love the cyclamen. This foliage comes up generally in August and persists through the winter. And it will eventually die down in May or June. Beautiful foliage and they finish flowering, they actually finish flowering around Christmas. And I love the fact that once it finishes flowering the old flowers actually coil up to protect the developing seed.  So once that seed is ripe, then it actually uncoils like a spring and just shoots the seed (chuckles from the audience). So, it’s just a fascinating little plant, that nature could come up with a neat device like that. Cyclamen are one of those plants that you want to put where nothing else will grow… in the shade. So, at the base of a tree that never sees any water, that’s where cyclamen will thrive. If you put cyclamen in good garden conditions, they will die. Put them where they get summer moisture, they’ll die. So, you want them in the absolute worst conditions in your garden. That’s where they thrive.

There are a number of wonderful evergreen ferns. You’ll see a fair amount as we walk through today. This is one of my favorites, this is Seibold’s dryopteris. Named after a famous plant explorer named Von Seibold. This stays completely evergreen. It’s getting a little too much sun now that we took the hedges off. Again, texturally, there’s really nothing quite like the evergreen ferns. And here’s more of the ferns, same genus. The wonderful dryopteris. The most common one is one called autumn fern, Dryopteris erythrosora, which look fabulous in the wintertime.

Dentaria Makes a Splendid Winter Groundcover

We talked a little about groundcovers earlier. I think this is one of the most splendid groundcovers there is for the wintertime. This is our native toothwort. The genus, of course, dentaria, which is Latin for “teeth”. This is actually in the same family as cabbage that we eat. Even though that seems sort of weird, the flowers that will come up, in about another 6 weeks, are about a foot tall, beautiful light mauvy-lavender, but you’ve got this wonderful foliage through the winter and often the leaves have a beautiful purple underneath. I think it’s just fantastic. I’m not sure why this is not grown more. Extremely easy to grow. The soil is either moist to slightly dry.

Now some more different hellebores, we looked earlier. This is a really interesting group. This is a new group. Been around, probably now about seven, eight years. Where they took the Christmas rose and crossed it with the Lenten rose which was supposedly not possible, and they came up with this whole series of really neat foliage that has this silver mottling. I think the foliage is even better than the hybridus, which are nice, but love this color in the winter garden and there is quite a number of these out right now - Anna’s red, Penny’s pink, Molly’s white, quite a few different ones.

Q: Tony, what did you call the groundcover?

A: This is toothwort or dentaria.

Now if you follow taxonomy real close, they’ve actually decided that toothwort is no more, and they’ve moved them all to a genus called cardamine. Which, I’m not really thrilled about that, because one of the plants I hate in cardamine is bittercrest. So, this is actually a first cousin to bittercrest. Bittercrest is a problem weed and an annual, this is not a problem weed and it’s a perennial. But you know how those taxonomists are, that’s what they do.

Another really interesting evergreen groundcover, another native, is Erigeron pulchellus. It gets to looking a little rugged by the end of the year. Here’s last year’s leaves, we’ve just cleaned those up. The new growth is already coming out. Fantastic groundcover. Real easy to grow, doesn’t take a lot of sun. And then the flowers are about this tall. They look like purple dandelions. Doesn’t seed around, not weedy like dandelions. Erigeron pulchellus. If you haven’t tried that, especially if you like native evergreen groundcovers, it’s just hard to beat this plant.

Earlier we showed you one of the toothworts, right over there, here’s a different species of toothwort that comes into bloom early. That’s another of the great natives. That was one called diphylla, this is angustata. This one is a much smaller plant and doesn’t spread nearly as much.

Another plant, we’ve just cut the old foliage off. Some years it’s completely evergreen other years it’s looking a little rough, as this one has, by the end of the year. These are farfugiums. These are actually first cousins to chrysanthemums. They’re basically chrysanthemums for the shade. They grow this wonderful foliage and then they flower right around Halloween with beautiful stalks of yellow daisies.

I think I’ve already run a couple of minutes over so I’m going to stop here. If you’ve got any questions, I’m around. I hope this does give you a little idea though of the possibilities. We could have a garden of all evergreens if we wanted. There are so many choices here. It’s just really amazing.

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