Thursday, 2 October 2014

Is this "Sudden Death Syndrome"?

My Cotinus ("Royal Purple") has suddenly gone looking very sick.


At this stage of the year its leaves are usually very "autumny". They fade from deep purple to an orange-tinted russet colour, in which the ribs and veins are very prominent - like this:


Photo from 2011

However, this year things are very different. Some of the leaves have just gone a horrible brown:


That doesn't look to me like "Autumn colours". That looks dead.


Even some of the less brown leaves are curling up, which is not normal.


Not all the leaves are affected (yet), but even the best of them have a dull matt look, whereas I would normally expect them to be quite shiny still.


I have no idea what might be the cause of this. Possibly insufficient moisture, although big shrubs like this one normally tolerate much worse conditions than we have had recently. I know that September has been warmer and drier than usual, but nothing too dramatic. I rather suspect that the Cotinus has been struck down by a disease.

Since the leaves would be dropping off anyway, I don't think there is much I can do apart from wait until next Spring and see if it revives. I hope it does, because I love that tree!

20 comments:

  1. I hope it lives for you. I love plants that turn beautiful colors in the fall. Our leaf season has just started here.

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  2. Could be verticillium wilt. RHS have good diagnostic photos - blackening across stem in cross section...

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    1. Thanks, Phil. I have looked at the RHS website, and I think you may be right. The fact that it may appear suddenly during hot dry spells seems in keeping with our September weather. I'm just hoping that the disease will not affect the whole plant.

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    2. I tried layering my Cotinus "Grace", and so wounded a stem before burying it. That let the fungus in, and I lost the original plant. Strangely the layer was a success, but I imagine it is carrying the lurgy...

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  3. It certainly doesn't look very well at all. I hope you find the cause and can rectify it before it's too late.

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    1. If it is Verticillium Wilt, the plant is probably doomed. The RHS says there are no chemical remedies available. :(

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    2. Unfortunatelly. I saw such example during my internship at Kew gardens.

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  4. That's a shame if it cannot recover, it really is looking poorly.

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  6. My smoke bush did this last year - I cut out the affected parts and so far so good!

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    1. Hi Gill; OK then, I'll follow suit...

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  7. The same thing happened to my hydrangea petiolaris - maybe cutting off the dead parts will help to rejuvenate it.

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  8. p.s. how did you get the UKVG on your side bar - it won't work for me - the site isn't letting me know when anyone leaves a comment for me either - any advice?

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    1. Hi Elaine; I have sent you a personal email about this.

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  9. I think many plants suffer from sudden death and the causes are numerous, not least belated reaction to water logging, drought caused by overcrowding or just lack of rainfall and of course numerous pathogens. It is sometimes difficult to know that a pathogen was able to invade because of these physical things.
    Last year I lost a large cotinus- nearly a metre high with sudden death at this time of the year.
    It had been given me as large container grown plant the previous Spring and of course I was aware it would need occasional heavy watering that Summer. It seemed to be thriving and then, bingo it was showing exactly the same symptoms as yours!. I wondered if I had relaxed my watering too soon in a dry Autumn!

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    1. Thanks Roger. At least I know I'm not alone! About half of my shrub looks OK still, so I'm hopeful that at least some of it will survive.

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  10. Nah, not sudden death. Not enough water. Give it a slow soak around the roots. Or cut out the brown stuff now because it is ugly and painful to look at. It's just self pruning to protect itself. A lot of plants in the sumac family (Anacardiaceae) do this.Then after it drops it leaves, cut it back some more so next year it doesn't outgrow its water. Mine does this crinkling at the top, too, near the end of the season. I love this tree, too. I first saw it in Cambridge Botanic Garden in the 1980s and when I got home to southern California, I had a long search to find one but eventually did.

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  11. I think lack of water. Just my two pennies worth

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  12. I do hope it recovers. A mature weeping tree near here (I don't know what it is) suddenly died in the middle of summer. All the leaves just suddenly went brown and crispy for no apparent reason. Such a shame, it was a thing of beauty.

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  13. Just had the same thing happen in a garden I'm working in. I cut out the dead wood and found black stains in the sapwood, so cut back all the way to the point I could no longer find any staining - thinking it was some sort of canker or some such. I've now come to the conclusion it's verticillium wilt. Oh dear. http://www.extension.umn.edu/garden/yard-garden/trees-shrubs/verticillium-wilt/

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