Tsuga mertensiana & Picea sitchensis help

Discussion in 'Pacific Northwest Native Plants' started by EarthyGirl28, Apr 14, 2021.

  1. EarthyGirl28

    EarthyGirl28 New Member

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    Location:
    Coquitlam, BC
    We lost 2 trees planted last year (Mtn. Hemlock & Sitka spruce) and have no clue why.

    The Sitka was a seedling - one of the many we distributed at out wedding, 21 years ago. It had been in a large pot (as we lived in a condo, until a couple of years ago), and was planted just last year, in a fairly shady spot (morning and late afternoon filtered sun).

    The Hemlock was planted last year as well, in a partly shaded spot (shade in the mid to late afternoon).

    The environment is riparian/woodland; they are on the bank, uphill from our creek, in SW Coquitlam. Much care was taken in preparing the site: organic compost/fresh topsoil was mixed with the soil in situ; rock dust added for long term nutrients; organic "booster" fertilizer watered in (rec. by the nursery) to aid in their establishment.

    Sadly, the Hemlock is as brown and dead as can be - worst I've ever seen and the Sitka was more gradual, but a similar fate befell it.

    Does anyone have any ideas as to what may have caused this? the Hemlock was a robust potted nursery purchase, and the Sitka was so-so - we thought, because it needed more room.
     
  2. Margot

    Margot Generous Contributor 10 Years

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    Location:
    Nanoose Bay, BC Canada
    Being planted on a bit of a hillside makes me wonder if the trees got enough water. Mountain hemlocks in particular like moisture. Because the tree roots would not have had time to extend beyond the original planting hole, they should not have been allowed to dry out at any point. It would have been a good idea - and maybe you did this - to leave a hose dripping very slowly over the root zone during the dry months.

    Also, in a perverse way, you may have created an environment where the roots were not tempted to grow beyond the very rich soil in the planting hole. Experts like Dr. Linda Chalker-Scott advise against improving the soil at all but, instead, mulching with a thick layer of arborist wood chips.
    Problems with Planting Trees
     
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  3. Ron B

    Ron B Paragon of Plants 10 Years

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    Roots grow away from the center of a plant unless blocked by an impenetrable barrier. The main issue with amending of planting hole backfill is how movement of water into and out of the hole may be affected by this having been done.
     
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  4. EarthyGirl28

    EarthyGirl28 New Member

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    Thanks, everyone, for your thoughts on this.
    I am surprised to hear that the soil shouldn't be amended, because this is what I've always done and what is always recommended by nurseries and gardening shows, etc., but at the same time, it makes sense not to, after reading this. I am going to have my arborist come over to assess the problem and start over. If he says anything different than what's been said here, I will report back! :)
     

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