Identification: Dieback on row of Cedars

Discussion in 'Gymnosperms (incl. Conifers)' started by Derek Renaud, Sep 30, 2017.

  1. Derek Renaud

    Derek Renaud New Member

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    Location:
    South Western Ontario
    Hello,

    Along the side of my property I have been battling dieback on my row of cedars the last 3 years. Several plants have been relaced as well. I was originally told it was related to mites. The last two seasons the mites have been targeted with miticides and I believe controlled. Looking with a microscope I see very little insect pressure.

    In South Western Ontario we have humid summers. The side where the dieback occurs is shaded and the lawn is irrigated. I am starting to wonder if this can be related to disease rather than insects.
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    Any advice or input is welcome.

    Thank you in advance.

    Derek
     
  2. Frog

    Frog Rising Contributor Forums Moderator 10 Years

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    When you look up close at the leaf scales, the ones affected and browning, do you see any tiny holes?
     
  3. Michael F

    Michael F Paragon of Plants Forums Moderator 10 Years

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    They're arborvitae (Thuja occidentalis) not cedars (Cedrus spp.).

    It does look more like a fungal disease, but hard to tell without microscopic examination. Shade doesn't help either, they'll always be thin and open where they don't get enough sun.
     

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