Monday, September 27, 2010

Knot a Weed!

Persicaria amplexicaulis 'Taurus' and Schizachyrium scoparium, 'The Blues' Little Bluestem

Ahhh, the lovely, indispensable (and unfortunately named) knotweed, Persicaria.

Growing up in the midwest, we actually had knotweed growing in shady portions of our garden, amongst the hostas and (shudder) bishops weed. It was small, spindly and not much to look at, with little pink bottlebrush blossoms and, I'll admit, a weedy demeanor. Unbeknownst to me at the time, there was a host of garden-worthy varieties already being used (mostly in Europe). Who knows who it was that first started championing them, but I first noticed them in the plantings of Piet Oudoulf (my hero!). He used them to great effect, in large swaths, as edgers, and mixed in with other wild-looking plants like Rattlesnake Master, Sanguisorbia and Eupatorium. I don't think I really even liked them at first, even then...they reminded me too much of the weed I'd battled in a previous life. I've warmed up to them considerably, however, and now love them, in almost every form they offer!

'Taurus', pictured above (and to the right), is one of my favorites. It's too early to tell how it will fare in my garden, but they've grown considerably from when first planted only a month or so ago, and are starting to really take off. I honestly thought they might have been a dwarf version of the similar plants I'd seen in other gardens, the leaves and habit seemed so tiny and compact. It seems they only needed a month to settle in, and now are starting to rapidly increase in size...granted, they were tiny plants when I got them, but they've probably tripled in size within the span of a few months. Now that it's cooler and we've gotten some nice doses of rain, they are going like gangbusters. They have not stopped flowering since they were planted (I deadheaded all the blooms at that time...but they were already flowering a week later). Their flowers are a somewhat startling shade of fucshia at first, gradually toning down to a deep, rusty red. I love how wild, yet delicate they look, and they contrast wonderfully with the Little Bluestem Grass they are paired with. Their medium-sized, heart-shaped leaves are a wonderfully vibrant shade of green, and when stressed, they mottle with lovely red and orange tones (I'm wondering if they will have fall color due to this trait, we'll wait and see).



Persicaria virginiana
This may be my favorite Persicaria, at least for the moment. I positively adore its wonderful, light green leaves with their bold mahogany chevron. They really stand out and look wonderful next to everything, plus, they are soft and sort of "quilted", I can't walk by without reaching out and squeezing the leaves. I really like them next to the 'Blackie' Sweet Potato Vine, and it even looks nice weaving through the neighboring Salvia 'Purple Majesty'. It's actually started flowering last week...and they are strangely beautiful, but not immediately noticeable.


Persicaria microcephala 'Red Dragon'
Ok, I admit, I wanted this plant because a neighbor grows it, and I've envied it since the day I saw it! I've seen 'Red Dragon' elsewhere and thought it was only ok. The color was dull, the stems were spindly, the flowers, very "meh". When I saw this neighbor's plant though, I realized it COULD be beautiful. She corsets and cuts hers back in early summer, just as it starts to sprawl, resulting in a lovely plant. The color does wash out a bit later on, but it's still beautiful. The burgundy leaves have chevrons of green and silver, and when backlit by the sun, it looks like stained glass.



As if all this wasn't enough, it's also really easy to propagate! Earlier this summer, I accidentally snapped a few stems off as I was weeding, and decided there was nothing to lose, so I stuck them in a glass of water. Below, you can see them a month later, they started sending out roots after only 3 days! I decided once it started sending out new leaves underwater, it was time to plant them in the garden. Below, right, is the newly-planted 'Red Dragon' cutting. I've recently noticed a few self-sown seedlings of the same plant in the garden...although, now that I know how easily cuttings root, these seedlings could just be parts of stems that have fallen on the ground and rooted.

roots-jpg persicariasprout

So, there you have it...Knotweed, aka Persicarias. They are tough, vigorous, and dare I say it, even a little whimsical...a tall order for any plant. A side note, Persicarias really haven't caught on in my area yet, and as such, are relatively hard to find in local nurseries. Luckily, I found them this spring at one of my favorite nurserieies, Joy Creek Nursery, in Scappoose, OR.

I leave you with a shot of an actual knotweed in my parking strip! It's true, just the other day, I realized I did have a "weedy" knotweed right here in my garden. It's tiny, only a few inches high, but has survived all summer and is now flower...I might even dig it up and move it into the charming would it be in front of 'Taurus'! These plants may be weeds to some, but I wouldn't be without them!



  1. I think the 'taurus' is very pretty. Scott Calhoun's book about plant combinations uses rattlesnake master a lot. I haven't been able to find it here. I will have to look for the 'taurus'. Also, the persicair virginiana is such a great color. I'm glad to learn about that one, too. I have 'red dragon' ... good to know that I can just stick clippings in the ground. I learned a lot from this post! Great blog!!

  2. This is a really great blog! Wonderful pictures and words. Am really going to enjoy following!

  3. Hi Scott,
    I have that weed in my garden, too. Last year I used it in a floral arrangement for my dining room table. I did not know they actually sell it, although I think it is quite lovely!

    Thanks for the info.

  4. I love the Persicarias too, I have Red Dragon and Painter's Palette. I think I will try cutting the Red Dragon back. I bought three from Bluestone this spring, and they are already sprawling all over the area where I planted them. Nice to know the cuttings root so easily too.

  5. Love the color echo with the Little Bluestem. It is a great combo. Super post!

  6. Those are some very nice persicarias! I've only killed 'Red Dragon' once, so I should try again. Have you tried firetail? - it's like an overgrown taurus!

  7. I seem to have bad luck with the Persicarias- my Red Dragon died in the bad winter before the last {Portland} bad winter. MY painters palette, died last winter, though I think I was being punished for pinching a stem from a church garden on my walk.

  8. Loving the
    Persicaria microcephala 'Red Dragon' you just shared! Can't wait to stop back again and enjoy your creative images.

    Happy Gardening - Bren

  9. Some would beg to differ on this Scott, but I do love the purple blooms on virginiana. :)

  10. The line between weed and disirable is thin in this genus. I guess it's all a matter of perspective.

  11. You've taught me something this morning..and that's always good :) I haven't seen the cultivated versions of persicaria before..except "kiss-me-over-the-garden-gate", which I think is related (but I may be wrong). I particularly like that purple one, but all the colors are pretty, including the leaves and stems.
    We have the "weedy" version here on the farm, growing in profusion! We call it Smartweed. Japanese beetles love it! I love the knotty little flowers as long as the plant is growing somewhere away from my gardens. We had a lovely stand of it blooming outside the milkhouse until a couple of weeks ago. When it begins to set seed it has to go! There's plenty more where that came from :)

  12. Hmmm... I wonder if it would grow in my neck of the woods. I sure like the look of it. I have an unfortunately named flower, Joe Pye Weed, that I like a lot, too.

  13. Hi Scott, Were you warned about P. virginiana? If you allow it to go to seed you'll be digging up seedlings for years. Literally. I'm still digging out progeny from at least five years ago.

    You didn't mention P.'Painter's Palette.' Its green, white and pink mottled leaves are yummy! And of course Kiss-Me-Over-the-Garden-Gate which is in its prime right now. Want some seed?

    I never call it Knotweed. It's Persicaria. LOL And it's simply Joe Pye. Not Joe Pye and that final four letter word. No siree. :)

  14. Thanks for the comments, everyone!

    Amy: It is really pretty…and much more so in person! I have actually never seen Rattlesnake Master for sale…not anywhere around where I live (Portland, OR). I see it used in so many garden books and magazines…I wonder where they get all those wonderful plants?!?

    Charlotte: Thanks so much for stopping by!

    Zoey: I love that! They really are quite pretty, I think people are just starting to warm up to them.

    Dirty Girl: Indeed :-)

    Alison: They do seem inclined to sprawl. I've decided to let them do what they want this year (although I did stake the Red Dragon…I kept finding stems wandering through plants 8' away!). Next year I'll be a little more judicious with pruning and staking…especially Red Dragon…it's beautiful, but needs some "guidance", shall we say ;-)

    Compost: I do too! It's one of those combos I sort of imagined in my head when I spotted 'Taurus' in the nursery and it's worked out far better than I thought!

    Gardeningasylum: You should give it a try again…it's so lovely! I've not been able to find 'Firetal' locally, but am keeping an eye out!

    Linda: HAHA…that's funny, I'm always tempted when walking by gardens to do just that…but my Protestant upbringing instilled a bit to much guilt to actually do it…now if it was a broken stem on the ground, all bets are off!

    BGgarden: Thanks so much for stopping by!

    Racquel: Oops…I think the blooms you're referring to are the 'Purple Majesty' Salvia it's planted next too…if you're referring to the pic above…here's the flowers for P. Virginiana below…they are kinda tricky to photograph!

    Les: Totally…I think the definition of weed is something like "The wrong plant in the wrong place"

    Kerri: Thanks so much for the compliment! I know, I was surprised at first when I saw people growing it on purpose! We were the same way on the farm, as long as it wasn't a nuisance, we let it be!

    Kate: I think it would grow for you…but I'm never sure of zonal boundaries ;-) I ADORE Joe Pye Weed…it's one of my top 10 plants of all time!

    Grace: I wasn't warned…but pretty much figured anything related to the weeds I grew up with could have the tendency to be weedy itself! i'll have to definitely keep an eye out for those seedlings…thanks for the heads-up! Strangely, although I saw 'Painter's Pallette' last year in nurseries (and kick myself for not buying some) I couldn't find ANY this year…it's so odd :-( I adore Kiss-Me-Over-The-Garden-Gate! I saw some in a neighborhood gardens a few weeks ago and, again, made a mental not to grow some next year…I would NEVER turn down seeds :-)

  15. I think that first kind is what I keep forgetting to ask a friend of mine for a start of or seeds for. She's the one I got my kiss me over the garden gate seedlings from. I think they'd look good in a bed together.

    I didn't know those plants were related to each other. Thanks for the information.

  16. I forgot to say the one in the third photo reminds me of painter's pallet. I wonder if they are also related. Oh, silly me. I just looked up painter's pallet and found that it is the same thing. The color of yours is a little greener and has less red than mine. Yours also is without the bug holes mine have in the leaves.

  17. Hi Sue...thanks for the comments! Let me know if you want some...not sure how well they would surive the trip, but I can take some cuttings next spring for you...I'm sure they are as easy to start as the Red Dragon! I think you are right about those two plants being the same...just different culitvars with different patterns on the leaves.

  18. Scott, this is a great post on the knotweeds. Not many perennials perform well here in zone 10, but P. amplexicaule is one of the few exceptions. I just planted three Firetail in the garden yesterday. There's so many varieties now, the chartreuse leaf one, a pale pink, a white, but the old standby Firetail is probably the most robust for me.

  19. Thanks Denise! I'm glad 'Firetail' does well for you...they are great plants! I'm amazed at how many new varieties there are out there, I'm constantly seeing new ones on other people's sites and always make a mental not to look for them!

  20. Hi Scott,
    I am cleaning out my mailbox. I came across where you offered me knotweed seeds. I don't remember if I let you know my neighbor friend gave me some.