Kerria deserves a Second Look



Kerria japonica, The Japanese Yellow Rose, has been around for a long time. It has been sold for years, most commonly by low end mail order companies. For whatever reason, wholesale growers and garden centers rarely include this plant in their mix, and I wonder why? The more I see of this plant and what it can do in the landscape, the more I feel it deserves a second look. Please join me.

Kerria japonica is a hardy (Zone 5) deciduous shrub that matures at 3 to 5 feet in height. It's a dense mounded plant with numerous slender, zig-zagging branches that emerge at ground level. The beauty of Kerria is found in its flowers, stems and foliage. The bright yellow flowers are noticeable reminiscent of an old fashioned rose with its 5 petals. The flowers clearly make this plant a member of the Rosaceae family. In early spring, before the leaves emerge, the numerous yellow flowers create a colorful show. As an added benefit, Kerria will often rebloom off and on all summer long. The effect is beautiful and rewarding. Kerria is also blessed with attractive ornamental stems. From autumn to spring, its bright kelly green stems create a wonderful, fresh impression. Having visited the Cincinnati Zoo and Botanical Gardens in early spring a few years back, I distinctly remember big green drifts of Kerria. I was surprised and delighted to see it used throughout their beautifully landscaped grounds. Around every corner we were greeted by a mass of bright green. This unique combination of color and zigzagged lines creates a lasting impression.

You also have to appreciate the clean and simple foliage of Kerria. The leaves appear birch-like at first glance with its narrow triangular shape, but unlike birch, its leaves are brighter, doubly serrated, and display a pronounced puckering between the leaf veins. Always clean and green the foliage is a distinctive asset.

Culture


This is not a fussy plant that is difficult to grow or manage. Quite the contrary, Kerria is happy in most any reasonable well drained soil. It requires little fertility, and seems to flower best if neglected. Unlike other members of the rose family, Kerria has no serious insect of disease problems. The remarkable thing about this is that it thrives when grown in partially shaded to fully shaded locations. Few plants flower this well in shade! Full sun is also an option, but it does present a few problems. The flowers do not hold up as well and it can show some stem die-back if exposed to winter sun. Neither of these problems are severe, but both can distract from the beauty of the plant. It should be noted that this plant dislikes heavy, poorly drained soil. It will languish and grow smaller by the year. As far as ongoing maintenance, I personally feel this plant benefits from an occasional hard pruning. Cutting the plant to the ground produce a fuller plant, brighter stems and improved flowering.

The Cultivars

The most popular cultivar of Kerria is the old fashioned double flowered form, Kerria j. 'Pleniflora'. Its yellow button-like flowers resembles a chrysanthemum, and at peak bloom they polka dot the plant to create a distinct look. Kerria 'Pleniflora is not one of my favorite plants. To me it looks too contrived. I much prefer the simplicity of the single flowered forms. Two of the best single flowered cultivars are 'Honshu' and 'Golden Guinea'. I can detect only slight and inconsequential differences between these two plants. Both were selected for their large single flowers. If I had to choose only one of them I would pick ‘Honshu’ because its flowers are slightly larger and they have a soft and pleasing fragrance. The plant was introduced by Dr. Clifford Parks of Camellia Forest Nursery in Chapel Hill. Many people choose 'Golden Guinea' strictly because of its name. The name properly describes the size and color of the bloom. No the name Guinea does not refer to a bird or some exotic country, it refers to a large gold coin.

For those of you who need even more excitement in your life, several variegated selections are available. The best variegated type is called Kerria japonica 'Picta'. Not a great name, but a very good plant. Its leaves are graced with a creamy white margin that is not at all offensive like some variegated plants. The overall effect is very nice, and a decent specimen garners much attention. It does have its shortcomings. It can be slow growing when young making it difficult to produce especially when compared to the species. It also has a tendency to throw an occasional green shoot, which must be removed. This is a simple task and most gardeners would gladly pay this price to have such an interesting plant. I have seen another variegated clone under the name of 'Kinkan' or 'Auro-vittata'. This is worthless selection best left to the most ardent collector or relegated to the botanic garden. This "beauty" has green and yellow striped stems that tend to revert at the speed of sound and has small single yellow flowers.
While all Kerria selections have yellow flowers; the cultivar ‘Albaflora’ has blooms that are a near white, butter yellow. The color is more subtle, and I my opinion more pleasing to the eye than the typical bright yellow of the species.

Kerria is a beautiful plant with year long interest. Plant it in mass in a shady location and I think you'll be pleasantly surprised how nicely this plant performs. Very few flowering shrubs perform so well in the shade and you'll love the winter effect provided by its bright green stems.

38 comments:

  1. I have Kerria japonica 'Picta' and agree with you that this is a shrub more gardeners should try. My original plant is on the north side of my privacy fence, and has done quite well. I pruned it back hard after about 5 years and it came back stronger than before. It suckers a bit and one of the suckers ended up on the south side of the fence, by the east side of my house, and I let it grow into a shrub of its own. It has never gotten as large as the one that has more shade. I do have to prune out the occasional all green branch, but like you said, that is not a big deal.

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  2. Jeannie6:50 AM

    Would love to grow this. I live in the high desert in Santa Fe at 7500 ft. What are the water requirements? Can it live at 7500 ft in elevation?

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  3. What about 'Buttercup'? Or is this just an overenthusiastic application of a cultivar name to the single-flowered form?

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  4. Kerria 'Buttercup' is new to me. It may be as you say a regional common name for the single form of Kerria.

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  5. I bought a house five years ago with a Kerria Japonica 'pleniflora' growing in the "neglected" side yard (heavily wooded), though I didn't know it at the time. At one time the house was owned by a nursery owner so it had/has a lot of unusual plants. Since the Kerria was up on a rise, behind some other (8-ft.) shrubs, I didn't even notice it until June of the 1st year, when it sent suckers with beautiful yellow blossoms shooting overtop some of the branches of the other shrubs.

    Though I started to tackle some of the big problems that year (such as pulling the English ivy away from the trees) I didn't clear the ground of ivy; it's still there. Incidentally I didn't figure out what the yellow-blossomed plant was until the 3rd year, when I came across a picture of the Kerria in my garden book.

    So far so good. Shade? Check. Well-drained? Check. Pruned? No, so I did, toward early fall of that year, when I also cleared the ground in that area of English ivy, ripped the ivy out of the ground, and cut it away from other plants (though there aren't many there to start with). Unfortunately, that was the last I saw of the plant - it died and never re-appeared.

    That left me with two questions: one, what went wrong? Two, how do I replace it? I haven't found a garden center that stocks it.

    No roots were ripped from the ground; I didn't lop it off "to the ground"; I left some canes (though they were all brittle BTW) 2 ft. high, others were cut (or "snapped") just about to the ground.

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  6. It is hard to say what went wrong. Normally this plant is very difficult to kill.

    Fall pruning can at times encourage growth at a time when the plant needs to slow down and head into dormancy. But I find it hard to believe that this is the cause.

    Kerria should be available at better garden centers. Certainly you can buy it mail-order or via the internet.

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  7. In response to that posted above from Jeannie in Santa Fe NM,
    Hi I live in Utah (an ex-pat from south eastern England) and purchased four kerria japonica pleniflora from an online store here in the US. All four have done remarkably well but I discovered that they actually do better on an east facing wall. Utah gets the extremes of temperature and I live at 4600ft. I cannot imagine the plant not surviving the altitude where you are. It will do better with the cooler temps at that altitude. Water requirements: I have not noticed it suffering when I don't water every day. I water once every four to six days in the summer, twice and for only 40 minutes each. Our summers are hot (+100F sometimes) and this has not deterred the plants from doing well. Hope this helps.

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  8. In response to that posted above from Jeannie in Santa Fe NM,
    Hi I live in Utah (an ex-pat from south eastern England) and purchased four kerria japonica pleniflora from an online store here in the US. All four have done remarkably well but I discovered that they actually do better on an east facing wall. Utah gets the extremes of temperature and I live at 4600ft. I cannot imagine the plant not surviving the altitude where you are. It will do better with the cooler temps at that altitude. Water requirements: I have not noticed it suffering when I don't water every day. I water once every four to six days in the summer, twice and for only 40 minutes each. Our summers are hot (+100F sometimes) and this has not deterred the plants from doing well. Hope this helps.

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  9. jerome Johnson10:45 PM

    Tim: While it is nice to read your resume/profile, I feel it to be a bit distracting and self-serving. I know it was not your intention to elevate yourself above the gardening fray-but it is much akin to signing your name:
    Sincerely yours,
    Jerome Johnson, BA, MFA, Ph.d (now isn't that boring?)

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  10. Anonymous3:48 PM

    Lots of folks in my neighbourhood used to have Kerria hedges. People took cuttings and spread it around. Last year apparently almost all of them died. I didn't see any of them while they were sick, but it was described to me as "rust". The leaves turned brown and the plants died. I appear to have the only one which is still OK. Does anyone know what this might have been, and what I could do to keep it at bay?

    thanks Mick

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  11. Anonymous8:10 PM

    Ok, So I have wondered for years: Can I get kerria to grow in Central Texas (zone 8). Well drained I do have, but I also have a long hot summer.

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  12. Anonymous5:39 PM

    Jerome Johnson,
    The beautiful thing about blogs is that you do not have to read them or participate if they are not of interest to you. Or, if you are too educated to enjoy them.

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  13. Anonymous11:49 AM

    can I grow keeria in zone 5 in oklahoma?

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  14. Anonymous10:14 AM

    Wow I find it hard to believe that most Garden Centres do not stock Kerria's. As a manager of a Garden Centre I have been purchasing this plant for many years. It is wonderful I actually came on line to research "Honshu" to see if it was hardy in our area. Zone 5 central Ontario. I have never stocked this one before.

    Question is Kerria not also know as "The yellow Rose of Texas?" I seem to remember reading that at some point.

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  15. Anonymous10:10 AM

    Can Kerria be grown in Mississippi?

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  16. Kerria can be grown in Mississippi.

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  17. I am happy to have found this info about Kerria. The one I am growing comes from a cutting, the parent plant grows healthy and wild in some woods near my house.

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  18. Anonymous8:35 AM

    Can Kerria 'Honshu' be grown in full sun? I just purchased one from my local Krogers store but it did not have growing specifications listed. I planted it in full sun - without any protection. Will it survive? (I planted it yesterday. Should I dig it up and put it in a partly shaded area?) Thanks

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  19. It will grow in full sun but it is happiest in partial shade. If you have a place in partial shade I would move it while the plant is young.

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  20. Ed Tondu6:13 AM

    Tim,

    I commend to your attention Viburnum Bodnandense Dawn developed by www.bodnantgarden,co.uk . Mine on the northeast side of my house (zone 6 - zip 11355) under a redbud tree blooms reliably in early April, rivalling the abeliophyllum distichum on the (sunny) western side of my house as the earliest blooming shrub. Is it hardy enough for Michigan? If not, could hardy specimens be selected by you?

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  21. what about the rust problem on the Kerria Japonica? I've had a large bush for several yrs. in shaded location every yr. rust. Usually I use a fungicide is this what you do for rust?

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  22. Popped in from a link on Botany Photo of the Day. I wish such a plant would grow in the middle of TX.

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  23. These grow like weeds here in Central North Carolina. Does well with our 20/30f winters and our 100f and humid summers. They look best when kept clean by removing old limbs once they are finished blooming and allowing the new limbs to take their place. Although if you want it to grow into a big shruby mess with sporatic blooms through out the Summer you would only need to remove dead or damaged limbs.

    Arthur in the Garden. Raleigh, NC
    http://arthurinthegarden.blogspot.com/

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  24. Anonymous4:32 PM

    The rust problem is called Phomopsis Twig Blight. This happened to mine as well.

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  25. Anonymous3:23 PM

    Can this be grown in South Florida

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  26. Perhaps Northern Florida, but no, Kerria is not a good choice for South Florida.

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  27. Anonymous1:28 PM

    Do you think Kerria would survive zone 3a (5miles north of the zone 4 line) NW Minnesota?

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  28. No, I don't think Kerria is a good plant for zone 3a. It might get by in a protected area and even flower if you have good snow cover.

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  29. Anonymous11:44 AM

    I just purchased a home in Kansas and thought the Kierra were weeds. The neighbor advised me to take them out. I started to but loved the flowers and just couldn't take it all out. The thought was to wait for the flowers to die off. It is at least five tall and three feet wide. How do I prune it without killing it?

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  30. Beth Goforth10:44 AM

    Ther have always ( at least the 50 years that I have lived here)been Keria schrubs in many of the gardens in my neighborhood near Memphis,TN. About 10 years ago they all died in a single season. Last year I say one trying to come back. Any idea why they died and did anybody else notice this?

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  31. Anonymous9:44 AM

    Do deer like Kerria? We are cursed with plant eating deer in Bloomington IN.

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  32. Kerria is generally considered safe to plant in areas with deer. That being said, when deer are starving they will eat anything.

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  33. Anonymous11:45 AM

    I saw kerrias in Germany and searched one out when I got back home. I rue that decision. I hope I will be successful in killing it when I finally tackle trying to rip it out. Others have said that it grows like a weed. Take heed. THIS PLANT IS INVASIVE. It has spread out in all directions in my foundation bed and out into the lawn. The deer have not touched it, darn! It will be quite a chore to eliminate it but I must. I have the double form and the pom pom orange blossoms are lovely but the plant is not. Are others' kerrias more tidy? There can be variety in a species, in different cultivars, just as there are some forsythias that are more unruly than others. I am in zone 4 and it does too well here.

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  34. Just because a plant grows fast, suckers or spreads does not make it invasive. Invasive plants are those that displace native habits by (most typically) producing copious amounts of viable seed. From what I have seen Kerria is NOT INVASIVE.

    If you are looking for a slower growing kerria then select the variegated form called Picta for it is much slower growing than the others.

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  35. I didn't mean that it's an invasive species but the roots are invasive. Google "invasive spreading roots" and you'll see lots of hits for that usage of the term "invasive." I've always thought of plants like Lysimachia, Rudbeckia laciniata or more commonly, mints, as being invasive in that sense of the word. One needs to be careful to plant them where it won't matter if they spread. It's unfortunate that the term invasive has two meanings in general use. Perhaps "aggressively spreading" or "vigorous spreader" would be less confusing terms. Thanks for the suggestion about Picta but it is very short for that spot and doesn't have the beautiful pompom flowers. I am sadly in the process of engaging a landscaper to rip up the kerria. I think I'll plant a couple of tree peonies in its place. "Its" is not exactly the right term either as there are hundreds if not thousands of shoots in that spot from one original little plant!

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  36. Anonymous5:57 PM

    I have several Kerria Japonica and thet all came through the winter looking bad. About 1/2 of 70% of the stems on each bush appear to be dead..Do I let good stems bloom and then cut them back so they will grow back from the roots, cut out the dead tops or what..Any suggestions..

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