Hedges: Help on cedar hedge death...

Discussion in 'Gymnosperms (incl. Conifers)' started by Laris, Nov 1, 2007.

  1. Laris

    Laris Member

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    Bowen Island, BC
    I recently ( early May ) planted a hedge of Thuja Emerald Green Smargard and on close inspection this week it appears that they are all dead. They look green on the outside but seem to have been infested with spider mites? ( there is webbing present ) and are dead on the inside.
    Their location was part shade, decent soil, and along a cedar fence.
    I didn't think spider mites were that much of a pest. Before I go ahead and replant this hedge, I wonder what the most likely cause of death would be:
    air flow, the mites, or the part shade?
    I'd like to replant along this same fence and am looking for suggestions if this turns out to be the wrong plant for this place.
    Thanks!
     
  2. Ron B

    Ron B Paragon of Plants 10 Years

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    More likely lack of water or too much water in soil, if balled in burlap original field soil rootballs may have dried out and been resisting moisture coming in from soil around them. If you crack some open you may find dust. If not, dig in soil around them and look for signs of standing water or other forms of excessive dampness. If site prone to sogginess and infested with water molds that have rotted roots and killed planting, re-planting fresh stock into same situation liable to produce similar outcome.

    Cultivar name 'Smaragd' is improperly translated into Emerald for domestic sales, full botanical name of plant is Thuja occidentalis 'Smaragd'.
     
  3. Laris

    Laris Member

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    Hmmm, definitely not a soggy site and they weren't burlapped plants but rather potted ones and originally very healthy stock. So that would leave too dry but with all this rain? Webbing? Where the webbing occurs the branches are grey, not brown but grey.
    I have 2 cherry trees in front of them, I've pruned it back to allow more light and air, I wonder if they offered too much shelter from the rains...
     
  4. RonLiz

    RonLiz Member

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    I would suspect spider mite - as 40 out of 100 Smaragds planted last Nov, are dying. I was careful about their planting and watering this summer. I read about doing a test for spider mite by using a white paper under a 'bronzed' section of the tree and giving the tree a shake. I came up with tiny little dots, and when smeared on the page left red streaks which indicates mites. I have been hosing the trees twice a week [during the dry season] which is suppose to help getting rid of the mites. I also cleaned out all the debris inside the tree where mites will winter. Not sure yet if I have saved any. Did your trees start showing bronzing on the warm side [sunny] first, as that is an apparent sign also of mites.
     
  5. Laris

    Laris Member

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    No, they are dying on the fence side, so I think it would be an indication of poor air flow and perhaps a protected side the mites like better? I have 3 now that are completely dead and so need to be replaced. I'm annoyed as these are supposedly sturdy plants...at least they aren't as expensive as Hicks Yew though.
     
  6. alex66

    alex66 Rising Contributor Maple Society 10 Years

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    for me the cause is not good dreinage in the hole ,this is the cause of fungi that"attack" the roots system ,or the trunk is planted more deep (when planted tree the trunk can on ground level)if you soil have no fast dreinage planted more up like on small hill this is a good solution;if you are near this tree the lawn with automatic system of watering turn the "pop up"far to the trunk...
     

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