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.

—Tom McKusick


  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

  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!

  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.

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