Happy first full day of spring, all! Unless you’re in the other hemisphere, of course, in which case, it’s the start of autumn. We could actually split the difference and say happy winter, since it’s still decidedly wintery here, no matter what the calendar says. I wish I could have done a Bloom Day post back on the 15th, but it would have been awfully short. So instead, I decided to write about one of my favorite perennials.
The burnets (Sanguisorba species) as a group are sadly underused, and I don’t know why. Granted, they’re not widely available, but they’ve been around for a long time, so it’s not like they couldn’t be more popular if there were a demand for them. Maybe it has to do with the reputation some have for being rampant spreaders, but many other aggressive perennials are easy enough to find. Burnets come in a variety of heights, so there’s at least one to fit any spot. And though they have a distinct preference for sunny sites, with soil that’s on the moist side, that hardly qualifies them as fussy or hard to please.
Like many other members of the rose family, burnets can be magnets for Japanese beetles. But in their favor, they don’t seem to be appealing to either rabbits or deer–at least those who live around here. Your mileage may vary on that front. [Edit: If you read the comments below, you’ll see that other gardeners do find that both bunnies and deer can be problematic. Sorry! I can only say that I haven’t…yet, anyway.]
I’ve been growing several species of burnets for years now, and each has its good points, but I’d pick Japanese burnet (Sanguisorba tenuifolia) as the clear winner for its vigor, stature, distinct clump-forming habit, and late summer-into-fall peak. Native to eastern Asia, it has a rather wide hardiness range over here: reportedly Zones 4 to 8. Best of all, it offers two distinct options in one species. The one with deep purplish red flowers usually goes by S. tenuifolia var. purpurea or ‘Purpurea’, while the one with white flowers is sold as S. tenuifolia var. alba or ‘Alba’.
Both lack petals–the color comes from the sepals–and both have a cylindrical inflorescence. The white is distinctly arching, while the purple is more variable: sometimes upright and sometimes arching.
On the purple, the stamens are very short, barely extending beyond the sepals (if at all), while on the white, they extend noticeably beyond the sepals, giving the heads a fluffy appearance. That seems to make the white much more attractive to bees and other pollinators, though I have seen them on the purple as well.
Habit-wise, the two are fairly similar, producing basal clumps of pinnately compound leaves with toothed leaflets (typically more shiny on the white than on the purple).
Slender, branching stems rise from the center of the clump, with the infloresences held at the very tips. I’ve seen a number of descriptions listing the height to about 4 feet, but here, established plants of both easily reach 6 to 8 feet here if left alone. They can also be sprawly, unfortunately, especially in windy sites, but it is possible to prevent or minimize that with pruning or careful placement of sturdy companions (more on that later).
As I mentioned, it can be difficult to find Japanese burnet for sale, especially in the U.S. Your best bet is to search for seeds (details on that toward the end). Expect seed-grown plants to take 3 or 4 years after you move them to your gardento really settle in and fill out. Once established, they seem fine without division. I have some clumps that are easily 10 years old and show no signs of weakening.
With all the variability in Japanese burnet–particularly the purple variety–there is a lot of potential for selecting distinct forms, so there will likely be more named cultivars in the future if the plant ever becomes more popular.
Pink-flowered plants sometimes pop up, too; ‘Pink Elephant’ is one that’s been named.
Have I piqued your interest about this underused perennial yet? Let’s take a look at its appearance through the seasons and see if I can convince you to consider it for your own garden.
Sanguisorba tenuifolia in Spring
Japanese burnet usually emerges in late March here in southeastern Pennsylvania. The basal foliage of established clumps can easily fill a space 24 to 30 inches across by early to midsummer, but its vase-like habit in spring provides planting opportunities for companion bulbs.
Small, early bloomers, such as Crocus tommasinianus and snowdrops (Galanthus), fit nicely right near the base. Taller, later bloomers, such as narcissus, tulips, and summer snowdrop (Leucojum aestivum), work well 8 to 10 inches out from the crown: far enough to come up through the burnet foliage but not get smothered before ripening.
Like other perennials with handsome basal leaves and tall, slender stems–giant coneflower (Rudbeckia maxima) is one that comes to mind–Japanese burnet poses a bit of a planting dilemma: Do you plant it near the front of the border so you can enjoy the foliage as well as the flowers, or do you put it near the back, where the tall flowers fit in better? Either approach can work.
If you’d like to keep your burnet up close, count on cutting-back if you want to keep it short or propping-up if you’d like to enjoy it closer to eye level. When I find seedlings at the front of a border or close to a path, I leave them alone for the first two or three years to let them settle in; after that, I cut the plants back hard in late spring to early summer.
If you’d rather not deal with an empty space for a few weeks, another option is to leave some of the outer foliage and cut just the center of the plant.
The lower you cut, the lower the ultimate height will be. Clumps pruned this way will end up taller than they would be if you had cut them to the ground, however.
That center-cutting approach also works well for Japanese burnet clumps in the middle of a border. In that case, though, cut the stems about 1 foot above the ground in late spring to early summer. The effect will vary somewhat but usually reduces the overall height by a foot or two.
If you’re going to grow either the purple or white Japanese burnet near the back of a border, consider putting it behind a bushy, medium-height companion that it can lean on, so it doesn’t sprawl.
Whatever you do, don’t depend on staking that will hold the stems too firmly. Part of the charm of Japanese burnet flowers is the way they bob and sway in the slightest breeze, adding movement to the garden.
Sanuisorba tenuifolia in Summer
Once you’ve made it past the late spring to early summer cut-back–if you decided to go that route–there’s nothing to do with Japanese burnet for a while. If you didn’t prune them, the plants may come into bloom in midsummer (by the end of July here); if you did prune earlier, expect them to start in late summer. Here, at least, the white form typically starts a full week or two before the purple begins to bloom. Once they start, the two usually overlap in peak bloom for several weeks.
Obviously, the flowers of the white burnet are brighter and tend to be more eye-catching. They’re beautiful against blue sky but show off even better against a contrasting background, such as a rich green hedge or vine or a dark wall or fence.
Contrast is even more important with the purple Japanese burnet, because the flowers are so dark that they can be hardly visible from more than a few feet away.
There is an abundance of excellent partners for both of the burnets during their bloom period, whether you prefer charming harmonies or striking contrasts of colors and/or flower forms.
If your burnet plants start to sprawl around this time, it’s very difficult to stake them in a way that keeps their natural loose form. I do sometimes use Y-stakes to prop up single stems or half-round plant supports to hold up a group, or else do a bit of judicious pruning to remove some weight from individual leaving stems.
If you find yourself having to do more than scattered propping, consider trying pre-emptive pruning or adding a bushy companion in front of the clump next spring.
Sanguisorba tenuifolia in Fall
White Japanese burnet usually passes its peak by early September here, but the purple goes on well into fall. Combination options continue with asters, grasses, and other late bloomers.
Purple Japanese burnet holds its color long enough to combine with the fall foliage of deciduous trees and shrubs, too.
Both varieties of Japanese burnet can be outstanding for fall color in their own right, usually turning bright yellow to golden yellow.
Japanese burnet (particularly the purple) offers some seedhead interest after flowering. The heads tend to crumble by mid-fall, but the remaining stems can linger through the rest of the fall, or even beyond.
As I mentioned earlier, seed is probably your best bet for getting Japanese burnet into your garden. If you find a source, I suggest buying only one packet to start with, to make sure that the source supplies the correct amount of properly cleaned seeds. It’s not unusual to get an envelope of chaff with few, if any, actual seeds, particularly through seed exchanges. The image below shows samples of uncleaned and cleaned seeds for both the white and purple.
I find that Japanese burnet self-sows freely here, but if I want to start plants for a particular purpose, I sow in fall or winter and leave the seed pots outdoors to germinate when they’re ready in spring. I’ve also seen advice that sowing outdoors in early to mid-spring, so the seeds can get around 8 weeks at 50ºF, will work. Or try the advice from Tom Clothier’s Seed Germination Database: “Sow at 20ºC (68ºF), if no germination in 3-4 wks, move to -4 to +4ºC (24-39ºF) for 2-4 wks.”
Because the first-year seedlings are small and wispy, I suggest planting them in a holding bed and letting them bulk up for a year of two before moving them to your garden.
In Other News
Japanese burnet won’t be blooming for a while yet, so if you need flowers as soon as possible (and who doesn’t, after this endless winter?), consider adding some hellebores (Helleborus) to your garden. Whether you’re looking to learn more about these splendid shade-garden perennials or want to acquire some choice selections, there’s an exciting event coming up for folks in the mid-Atlantic region: the Hellebore Festival at Linden Hill Gardens, co-sponsored by Garden Design magazine. Linden Hill is located in Ottsville, Bucks County, Pennsylvania.
Jerry Fritz will be giving a demonstration on hellebore care on Saturday; hellebore expert David Culp will be speaking on Sunday. There will also be a variety of plant vendors, and a few non-plant (but gardening-related) vendors too, including me! I’ll be bringing many of my best botanical castings, as well as a series of new photo notecards, botanical sachets, and alpaca-filled nesting globes, among other things. For more information on this special event, visit the information page on the Linden Hill Gardens website: 2018 Hellebore Festival. It would be great to see you there!
16 thoughts on “One Plant, Three Seasons: Sanguisorba tenuifolia”
I have the S. tenuifolia !! …and love it ! Seeds came from you and just two weeks ago I was busy WinterSowing more. I’m nuts for grasses and really, really like it with my grasses…Thanks again !
That’s wonderful news, Sherry; thank *you*. I’m so glad the seeds did well for you. I hope you have the opportunity to share them with other gardeners. Yes, it’s an outstanding partner for medium-height to tall ornamental grasses.
I’ve long admired Sanguisorba but, sadly, the plants are well outside my climate range. I hope your extended winter comes to an end soon. Best wishes with sales at the hellebore festival!
Sorry abut that, Kris. I know that most of my favorites aren’t suited to your very different climate. Thank you for the good wishes. It should be a busy weekend at the festival: there are a lot of hellebore fanatics around here!
Great post, Nan, on an underused (at least in this country) perennial. The Europeans are way ahead of us on this genus and have lots of named varieties already, but as you noted they are very hard to come by here!
I’m trying several out right now after failing with them years ago… seems rabbits at my previous garden loved them and ate them right down to the ground as soon as they emerged, but in my current garden the bunnies are not as much of a problem, so I live in hope!
Oh no – that is not good news about the rabbits! Maybe I just have too many other things that the bunnies prefer to munch on. Good luck with your trials. Let’s hope that more growers here start making cultivars (or even just the species) available.
Hello. I started Jap. burnet from seed…given to me by you. I love it. It’s a big plant and I wish my yard had room for more. I discovered last year that the deer like the foliage. Ugh.
Always enjoy your post.
I’m so pleased to hear that you too had good luck with the seeds, Mel. I’m sorry about the deer, though. So much for my comment about the plants being deer- and rabbit-resistant; I’ve been shot down on both fronts. I guess I’ve just been really lucky so far.
Right now the deer are eating my Sedum ‘Angelina’. I give up!
Oh, that’s not fair. What next?
Happy Spring Nan. Thank you so much for this post. I have been thinking about growing sanguisorba purpurea for some time now, so your post has come at just the right time. I see from one of your combinations you have it with Panicum Northwind and Purple Fennel, exactly what and where I was thinking of planting it, thank you so much. However, I won’t be planting one just yet, as like yourself weather is still winter here in the North of England. We need some milder/warmer weather to get things growing. I still have snowdrops in flower!
Good to hear from you, Allan! I hope your winter gives up soon so you can get busy planting. It’s going to take a long time for our most recent snowfall to melt.
Your garden is an absolute torrent of blooms and foliage. I enjoy looking at your photos. The burnet sounds and looks interesting. Does it reseed itself? I am leaning toward native plants of my region. Although as you can guess I am not a purist.
Hey there, Lisa! Thanks for checking in. Yes, both colors (and pink too) self-sow here.
Glad Bloom Day is back! I enjoyed the focus on the burnet family, such variety in one family! I browsed the gallery of your stock photography hoping to find the purple asters and goldenrod.
Thank you for the seeds. I started the zinnias in an empty egg carton on my window sill and they are about an inch high.
Happy almost-spring to you! I have many thousands of images yet to upload to the photo site, but I just added one of the aster and goldenrod shots in your honor: Symphyotrichum and Solidago. Good for you getting the zinnias started already. I hope they grow and bloom beautifully for you this summer.
When the image of purple asters and goldenrod popped up on the screen it almost took my breath away! I have a further question about the stock photography–if I purchase it does it give me the option to print it for framing or as a Mixtile? Can it be enlarged for printing?
Thank you for the honor!
You are so kind! I just sent you an email; let me know if it doesn’t come through.
Lovely, helpful article. I planted a young Alba a couple of years ago and it hasn’t done much yet. How nice to hear that it generally takes several years for them to really get going (especially if transplanted after the initial planting . . . hmm). Digging Dog Nursery online has several selections of Sanguisorba plants for mail order.
Ah yes, transplanting would very likely set it back for another year or two. But once it really settles in, I bet you’ll be delighted with it. Thanks for the source suggestion. I almost included a few links in the post, but availability changes from season to season, and people get annoyed when they read a post I wrote years ago and find that the links no longer work; sigh.
I must have inherited Robert’s bunnies because if I don’t protect my plants as soon as they emerge in the Spring, the rabbits completely devour them overnight.
My eight plants are 2 years old, originally from your seed, and reached 6 feet tall last year! They were pampered for two years, growing in a nursery bed rich in organic matter and received plenty of water. I tried staking them later in the season but I was too late. I wonder if they prefer rich soil and moisture to reach their full potential. I have 3 more plants that are located in a more dry location and they seem to be only about 4 feet tall and never required any staking.
I didn’t realize they take so well to pruning – thank you for sharing your wisdom; I shall manage them better this year.
I really appreciate you taking the time to share your own experience with the plants. There’s not much information out there about Japanese burnet, so I know only how it behaves here. Your comments are very helpful!
I just loved to be introduced to japanese burnet. But since I’m in the other hemisphere- in Brazil to be more exact- I don’t have great expectations about growing them. Thanks for the beautiful pictures, though, and congratulations for such a wonderful and highly inspiring place.
It was very kind of you to write, Orlando. I’m sorry you can’t try the burnet for yourself, but then, I’m sure you get to enjoy many plants that I can only dream about growing. Such is the way of gardening!
Hi Nan Thanks for the comprehensive tutorial about sanguisorba! The photos are so useful to learn which combinations look good. I have a struggling plant from your seeds several years back. It’s in difficult clay, my bad. Just started seeds for ‘Lilac Squirrel’ from HPS. The name has enormous appeal and I hope it produces. And I promise to treat it more kindly. Good to see a post from you again!!!!
Hi Tiiu! You may be pleasantly surprised yet by your Japanese burnet seedling. They do look like they’re sitting there for a while, then suddenly look splendid one spring and thereafter. Good luck with your seeds of ‘Lilac Squirrel’. The super-fluffy pink burnets don’t bloom very well for me, but the blooms really are eye-catching.
No one wants to talk about cutting something to the ground anymore! (Alternating canes and pollarding are other sensitive topics.) I am not familiar with these plants; and wouldn’t you know, several of the companion plants are strange to me as well. The close up pictures are more compelling to me than the pictures that show what the plants actually look like.
Hi Tony. As far as perennial pruning goes, I can understand why many people would not want large holes in their garden in early summer, just when things are expected to look perfect. And really, I find the Japanese burnet most attractive when it gets as tall as it likes. But it’s helpful to have pruning techniques to use when the situation calls for them.
Add me to the list of gardeners growing this plant thanks to you! I think it will bloom this year, the plants came along very well last summer. Now I’m looking forward to seeing them even more.
I saw your Instagram link on the side of this post. I’m such a slacker on technology, but I may have to give it a try so I can keep up!
Great to hear that, Frank! I hope you enjoy growing the burnet as much as I do. And yeah, I too resisted Instagram for a long time, but it’s been very interesting. You get to know a lot of creative people, enjoy some spectacular scenery around the world, and see many fantastic plants too.
Nan: Your post is such a welcome sight! It feels like spring is here. Here in NJ we just had a 10″ snowfall on the first day of spring! I have started the seeds you sent last fall. They are germinating, and I’m very much looking forward to planting them in my garden. Thank you so much for sending them!
Thanks, Nancy! Every time I hear that someone has had good luck with the seeds, I feel like a proud parent. And yes, it’s finally spring over here too. Long may it last!
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