Great Plants for Northern Gardens: Day 12 — Fleece Flower

Giant fleece flower

Giant fleece flower makes a dramatic backdrop for daylilies and other colorful perennials.

Giant fleece flower (Persicaria polymorpha) is an underused perennial that is a real showstopper in the garden. Quick to establish, within two to three years of planting it sends shoots up 5 feet. In late spring they will start bearing masses of creamy white flowers. Fleece flower continues to bloom profusely all summer, the flowers mellowing to a tawny tan in September. Because the plant is so tall, the blooms provide a real focal point in the garden, especially at a distance, and they rarely flop over. At maturity the plant will increase to a 5-foot-wide clump, so give it some room.

Persicaria polymorpha is a member of the knotweed family, but unlike that invasive thug Japanese knotweed it stays put and only increases its size where it’s planted. It doesn’t reseed either. Drought tolerant and hardy to USDA Zone 3, giant fleece flower prefers moist, fertile soil and requires at least a half day of sun. You can divide the tuberous roots in spring, and divisions should include a portion of the stem. You’ll find that it makes a
great backdrop companion to daylilies, roses, and ornamental grasses.

Giant fleece flower is available at a number of Twin Cities nurseries that specialize in perennials, but you may not find it at a general garden center. It’s worth tracking down however, because you’ll find few plants that require so little care and provide almost shrub-like scale with so much long-blooming splendor all throughout the summer. Once in bloom it’s certain to attract a lot of attention from your garden visitors.

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  1. Gail McKenzie on September 20, 2014 at 12:12 pm

    I have a fleece flower which is three years old..
    A number of the stalks ( stems ) are turning black
    and the plant appears to me dying.Can you advise me
    I can do to save it? Thank you so much for any help
    you can give me.
    Gail McKenzie

    • Portal Gardener on March 12, 2015 at 7:53 pm

      You never specified a Planting Zone… In 6B (with this and last year almost a 5), from year 1 they’ve started to die back around early to mid Sepember.
      I’ve cut them back every year to as far as 3″ shoot stumps during Fall Clean-up, those will rot away during overwinter leaving you thinking that you’ve just lost this huge plant.
      Fear Not… next years growth will emerge in the early Spring with stunning new shoots while widening the plant, and at the same height you had this year.
      I also found that they will fill back in nicely during the growing season if they are gently pruned due to rain broken stalks, or removing unsightly spent blooms.

  2. Portal Gardener on March 11, 2015 at 9:19 pm

    I also purchased 2 of these three years ago… only during an extreme wet peroid did I notice dark to black shoots late in the season (Zone 6B). The plants have always bounced back and performed well.
    For the first time I decided to dig one of them up and move the root ball this past fall, and to my surprise… it wasn’t much of a root ball. It looked like a 7″ clump of driftwood with 3 massive roots that were heading back to China regardless how deep I dug.
    For my own piece of mind, I sprinkled some rooting hormone powder on the mass before replanting in it’s new location. I also had some tubor’s that were a casualty of war that also got a dose of powder and planted in another location.
    Once the “Melt” has happened, and the newbies should start to emerge… I’ll report back! This plant is well worth the investment!
    The only draw back that I’ve noticed is that in early summer and after the blooms have begun, Large Black Flies are drawn to the panicles, and shortly afterwards the June Bugs swoop-in..

  3. Kathy Pieper on March 29, 2015 at 9:54 pm

    I’m not from the cities so would really appreciate the name of the nurseries that carry this plant. Can not find a seed source either. Thanks for any help

    • JO SAWYER on June 3, 2021 at 11:38 am

      I ordered mine online. It was in good shape and is growing well.

  4. Debbie on July 14, 2015 at 7:32 pm

    I planted one of these plants about a month ago. My plant was about 3′ tall with just a few stalks but each had several flowers. It looked like it was doing very well till this past weekend. All flowers are now an unattractive medium brown and Something is munching on the leaves. We also noticed quite a few flies on the leaves. My husband made a diluted mixture of baby soap and chili pepper and lightly sprayed the plant. Does anyone have any suggestions? I plan to call the NH nursery where I purchased it to ask their advice. Thanks

    • Mary Lahr Schier on July 15, 2015 at 9:29 am

      Has it been very rainy where you are? You might want to check for slugs. Definitely go back to the nursery. Some nurseries will offer a one-year plant guarantee, and the nursery people can likely diagnose the problem for you. Thanks for commenting!

  5. Bill on February 22, 2016 at 9:34 am

    I live in northern Wisconsin, and have found this plant to be aggressive. It may NOT be as aggressive as its cousin, it will send out shoots. Beware!! I put one in a large flower pot and submerged it in my flowerbed. The other, I totally removed because of its runners.

  6. Ruth S on June 6, 2020 at 4:54 am

    I have a Giant fleece flower which now grows to 7ft tall. It is 6 years old and grows abundantly in Zone 2b. It has full sun. . and stands alone in the middle of the garden. There is nothing special I do to it. I don’t mulch it either it has lots of snow cover in 3- -40C. Many people admire it and I wish I could get clear instructions on how to propagate it.. especially a video would be helpful.

    • Robin Neudorf on August 12, 2020 at 12:35 pm

      I too am in zone 2b. I’ve had my giant fleece flower for about 4 years. After the first year I had to move it. So in spring I dug it up, used a shovel to split it into 2 clumps. Replanted each clump and they both grew amazingly well! Now they’re in need of moving again (just too big for where they are) so next spring I’m going to do the same. Likely get 3 or more from each plant too. They are very easy to propagate. Good luck!

  7. Karen on July 29, 2020 at 7:02 pm

    I too have this plant in zone 2b and we had as low as -42 degrees Celsius this winter. It came up in the spring heartier than the previous summer and I love it. It is currently 5′ tall and wide. I plan on dividing it to put the 2nd plant on the other side of my Nepeta (purple catmint)…looks wonderful together. Purple, white and some orange lilies in the mix, lovely combination.

    • Lorilei on August 6, 2020 at 1:28 pm

      Karen i would love to see a picture of what this part of your garden looks like!

      • Shannon on June 1, 2021 at 12:52 am

        I have had two Persicaria polymorphas in my south central Wisconsin garden for over a decade.

        I do literally nothing to them, not even cutting them back. I let the dry stalks fall over and pick them up in spring. I have never watered them after planting, and I’ve never fertilized them. They are 7 ft tall and about as wide.

        They are utterly spectacular, with no pests or disease. They have not run at all, but merely broadened into larger clumps over the years. I cannot recommend them highly enough.

  8. Maureen Barthelemy on August 19, 2020 at 8:30 pm

    I’ve had this in my garden for 3 years, on the south side of my home, not a lot of sun because of 60 year old white and red pines. Just measured one of the stalks and it is over 8 feet tall! There are 4 stalks, so is not a fast grower/spreader in the shade garden. Other plants around it are hostas, wild ginger, meadow rue, jack-in-the-pulpit and large leaved aster. Bought it at an UM Extension Master Gardener sale. I am in Zone 3, SE St. Cloud.

  9. Berny Jacob on February 28, 2021 at 5:52 pm

    Would like feedback to Giant Fleeseflower’s wind hardiness & alkaline tolerance.

    It is available from T&T seeds, Winnipeg,

    • Mary Lahr Schier on March 4, 2021 at 10:32 pm

      I’m not sure about alkaline tolerance, but I’ve seen fleeceflower growing really well in southwestern Minnesota which is extremely windy.

      • jeff sherfey on March 13, 2021 at 8:33 pm

        Does this have a aromatic smell to it?

        • Mary Lahr Schier on March 15, 2021 at 8:33 pm

          I’ve never smelled one, but according to this article, it’s a bit like cilantro. You either love it or hate it.

  10. Mary on April 13, 2021 at 9:12 pm

    Beautiful plant.

  11. Bert of Georgia on June 7, 2021 at 4:55 am

    I just planted two in Zone 7b (NW GA) around the end of May 2021. Only the Stem attached to the wooden-root has grown, about 6″ in 2 weeks. The other stem (no wooden root) does not appear to be growing at all. Nevertheless, I’ll continue to nurture both with water and see what happens.

  12. Sherry Hawkins on June 9, 2021 at 7:12 pm

    I plant a tiny baby one 3-4 years ago. Never took off, each year it would start out looking like it would do better, then the leaves would turn yellow, then black, then fall off 🙁 never made it past 1-2 feet tall. I finally gave up this year, dug it up and threw it out.

  13. Laurie Hurt on June 28, 2021 at 7:22 pm

    Where can you find this plant? What nursery?

    • Mary Lahr Schier on June 29, 2021 at 4:33 pm

      This can be difficult to find in the nursery trade, especially now that we are past the spring rush. You may want to look online or ask your local nursery if they can get it for you. I know the Friends School plant sale has carried it in the past.

    • Kathleen Johnson on July 27, 2021 at 8:35 pm

      All Seasons Garden Center in Grand Forks, ND has them. When I bought mine in end of May, they had a number of pots available.

  14. Miep on June 29, 2021 at 5:56 pm

    I took down a dead caragana that was next to the persicaria and ordered an oak to replace it… The Persicaria has been so happy not to have a neighbour that it got HUGE this year. I feel terrible digging it out, and would love to save it, but do they transplant ok in the summer?

  15. Freda Gowan on July 22, 2021 at 8:15 pm

    I have a fleece flower and am curious if deer will eat it. Thank you in advance

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