propagating Kerria japonica 'Pleniflora'

Discussion in 'Plant Propagation' started by janetdoyle, May 15, 2009.

  1. janetdoyle

    janetdoyle Active Member 10 Years

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    Location:
    Victoria [Saanich, actually, northeast of Victoria
    I found two plants of Kerria japonica 'Pleniflora' by luck the other day, in a plant nursery, after several others had told me they couldn't get it this year...I only saw the single flower version and didn't care for that so much. I really like this shrub, I like its graceful flopping-over shape combined with the small yellow pompom flowers, especially attractive where I saw it along a street, up above the sidewalk in a shrubbery garden atop a stone wall, and the long floppy branches were spraying over the edge of the wall towards the sidewalk. I also saw the shrub this spring planted in a tall narrow pot, with the stems rising up tall and very green, in the protected tropical garden in Butchart Gardens near Victoria... it didn't look so "floppy" for some reason in that style and the green stems looked stiffer, possibly because it wasn't laden with bloom.

    I am waiting for my two plants, purchased while in bloom, fairly reasonable size, about 2 feet tall, I'd guess maybe a couple of years old, to harden up in their planted location, presently staked to prevent stems breaking. I have planted the original two in a semi-sunny spot, although I see that the plant is recommended for part shade. Since almost everything grows better in sun, I tried this location for a change -- it gets sun after 1 pm facing northwest, and is shaded a bit by a couple of small trees/larger shrubs in the same garden.

    A couple of the newer stems broke off the root very easily as I was taking the plants out of their nursery pots, and I have dipped them in a rooting hormone and planted them near each other in the garden soil, in a protected semi-shaded spot, trying to keep them moist. One looks a bit wilted, with the top curving over, the other is standing straighter and looks fine. I would like to propagate several new plants, and don't have a track record for doing this.

    I would like to plant one in a pot in the style I saw in Butchart, possibly growing it indoors in winter...

    The style of the shrub suits my garden in a couple of spots and the bloom colour is a nice true yellow.

    Can anyone enlighten me on how easy it is to propagate Kerria from cuttings or from stems from the root?
     
  2. kaspian

    kaspian Active Member 10 Years

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    Maine coast, USA, zone 5
    It sounds like you've got the right idea. Kerria is said to root easily from soft wood cuttings. If your cuttings are wilting (which can happen easily if you to root them outdoors), then there are a couple of things you could try.

    - You could reduce moisture loss by trimming back some of the leaves (about half, say).

    - You could protect the plant by covering it, for at least part of the day, with something like a 2-litre plastic soda bottle with the end cut off. If you cut the bottom off, a modest amount of air can escape through the hole in the top, which helps prevent too much heat from building up. Even so, it can get very hot inside there, if the plant is exposed to too much sun.

    - You can move the cuttings indoors, rooting them in ordinary potting soil in an east- or north-facing window, with or without some kind of cover to retain moisture.
     
  3. growest

    growest Active Member 10 Years

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    I would limit the cutting to about 4-5 inches...longer is going to be tougher for the stem end to provide enough moisture for such a length of stem.

    Also I'd be sure that the cutting is all this year's growth, not any woody stuff. As a rule cuttings are only taken from current year's growth, unless they are hardwood cuttings which happen in winter so doesn't apply to your kerria in May. If you could put some kind of humidity cover over the cutting/s it would reduce the wilting and give the thing a fighting chance at rooting.
     
  4. Millet

    Millet Well-Known Member 10 Years

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    Actually Kerria japonica can be propagated either by hardwood or softwood cuttings. - Millet (1,343-)
     
  5. janetdoyle

    janetdoyle Active Member 10 Years

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    The two stems which broke off were only about 8 inches or so anyway, they were at the side of the plants coming out of a drainage hole in the nursery pots [seemed really vigorous plants] and so far, with daily watering, are doing just fine, look a little more spritely -- I removed half of the leaves as of above advice. The main two plants are doing better than I have seen a newly purchased shrub do in a long time -- either it's the warmer weather or the supplier was a really good one [the producer of the plants was a name I haven't seen available before, no idea yet where it's located, but I like their work...]
     

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