Cedar Hedge is Dying Please Help!

Discussion in 'HortForum' started by MAG, Sep 29, 2004.

  1. MAG

    MAG Member

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    We have a long row of cedar hedge that appears to be dying. We have already lost a few plants in the row and it looks like more are going fast. We had an arborist look at it and on Aug 11/04 he sprayed for shot bore beatle, keitneia blight and cypress tip moths. Since then they have been getting progressively worse.
    Please see attached Pic.
    We hope it is not too late.
     

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  2. Ron B

    Ron B Paragon of Plants 10 Years

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    Maybe repeated sprays are needed. And a different pesticide would be used for one or more of these than the other(s). If the arborist is not scheduled to come back later for another application at an appropriate time, you should look each suspected pest/pathogen up yourself to see if you can get some idea what you might have, become familiar with what is supposed to be done about it. Also: mites or root rot might be other possibilities, I suppose, although I've gotten the impression the Keithia blight has become fairly prevalant up there.
     
  3. jimmyq

    jimmyq Well-Known Member 10 Years

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    At a glance at your post, your arborist either was poor at communicating his spray techniques or he lied to you. You cant really spray to stop Kethia blight, it is caused generally by excessive humidity (normally from overhead irrigation or persistant summer rains) and only occurs on (ok not only, but mostly), Western Red Cedar.... not Pyramid cedars as yours appear to be. I can't tell from the pictures what may be the problem but I would be happy to stop by and have a look at them in person to try to figure out what the problem is/was. It may not be possible to tell for sure but having a look is easy enough either way. I have never heard of shot bore beetle.... but you may have had cypress tip moth earlier this year. Spraying is usually a last resort rather than a first foray.
     
  4. jimmyq

    jimmyq Well-Known Member 10 Years

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  5. Ron B

    Ron B Paragon of Plants 10 Years

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    Blowing up your photo I see that they are, in fact, Thuja occidentalis 'Fastigiata' or a similar cultivar, and also that there is extensive discoloration outside of the dead (brown) strip. It looks like mite damage to me, something I see rather often on Thuja occidentalis cultivars down here during summer. Take a closer look and see if there is fine webbing with tiny specks, as well as a stippled (speckled) appearance to the affected foliage.
     
  6. cb2908

    cb2908 Member

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    I've just joined since I did a search on dying cedar hedges and found this site.
    I live in Vernon and in our neighborhood all the cedar hedges and junipers are dying just like this. So I hope someone has come up with an answer.
     
  7. jimweed

    jimweed Active Member 10 Years

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    Was that pic taken after the hedge was sprayed or before? It doesn't resemble mite, tip moth or any other insect that I have ever scene. The evenness of the tips that have turned white resemble burning, except in the middle at the bottom that is systematically missed, which kinda rules out a tip blight. Now there does look to be a couple of trees that are dying in the middle. This could be caused by water or root disease or whatever.
    If you want my opinion, I would spray it with copper while it is still cool out, just out of shear plant healthcare. Then I would deeproot fertilize it, to keep it acidic and give it a boost of new growth this spring. Definately monitor the soil dampness all summer and water it as it needs it. Insects are very easy to diagnos, they are visual.
    Tip Moths will show small cocoons on the tips in Apr.
    Mites will turn the hedge grey, then orange, not usually a hedge that size so evenly
    Kethia Blight is more of a problem on tree farms, or like Jimmy says.
    Not sure what a Shot Bore Beetle is.
    Anyway that is an awesome hedge, and I am sure for the most part it will be fine, except where the trees are dying, that is extremely serious. I would definately suggest you attend to that asap.
    Drought is another serious problem, but it is that nice green patch at the bottom middle that confuses me. Hoping your hedge turns for the better ,, Jim
     

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