Small leaves

Discussion in 'Maples' started by whis4ey, May 15, 2010.

  1. whis4ey

    whis4ey Well-Known Member 10 Years

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    Location:
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    After the most severe winter I can remember, a number of my maples are leafing out with much smaller leaves than normal
    The problem is that, in the past when this has happened, it has been a sign that the tree is under stress, and, sure enough it has died the next year
    This year I can see the end of a 15 year old Asahi Zuru (looking decidedly pitiful), two Garnet (one about 20 years old and the other, a high grafted one of about 10 years) a Shin deshojo that I have had for about 5 years, and a Kinran
    Anybody else having a similar experience?
    Any words of wisdom?
     
  2. maf

    maf Generous Contributor Maple Society 10 Years

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    Not exactly words of wisdom, but I suspect reduced root mass as the cause for the small leaves. I have seen similar small leaf behaviour in two year old containerised seedlings which later turned out to have had their roots eaten by vine weevils (or similar root weevils).

    If this turns out to be the case, then the question is what caused the root decimation? Vine weevils won't check a plant in the ground. The temperatures in Northern Ireland by themselves are not low enough to damage Acer palmatum roots in the ground. Is there a chance they could have been waterlogged in the late winter or early spring when the water table is higher than normal? These plants are adapted for growing on hillsides in free draining volcanic soil in a climate where most of the precipitation is during the months of June to September. Any saturation of the ground during the early months of the year is likely to lead to major root death and subsequent invasion by secondary fungal and bacterial infections.

    You may have considered these possibilities already, but I thought they were worth mentioning again.

    Good luck with these maples.
     
  3. mr.shep

    mr.shep Well-Known Member 10 Years

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    Location:
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    There are a lot of factors that can lead to a
    palmatum type Maple yielding smaller leaves
    than normal. Environmental stress, stress
    due to pathogens, stress due to nutrient
    deficiencies (Zinc and Magnesium deficiency
    can cause “little leaf“. Copper, Calcium and
    heavy metal toxicity can also cause little
    leaf) and sometimes stress due to overfertilization
    and even stress due to the wrong chemical
    constituent and/or formulation of a fertilizer,
    can all cause leaves to become small.

    To better identify what have caused the
    leaves to become smaller in size due to
    stress we may have to see some photos
    of the Maples in question. Generally better
    to see photos of the plant prior to showing
    signs of the stress, photos of the tree under
    duress and photos of the tree after its demise.
    It is not an easy thing to do to post photos
    of a tree we've had for 20 plus years or more
    and later on lost it. I know for me I have to
    accept blame for what happened to the Maple
    even when the plants decline may not have
    been solely my fault. I always think in terms
    of what I could have done to help matters,
    help prolong the life of the Maple, even when
    knowing that the end of the plant might have
    been near no matter what I did.

    A case in point is the boxed Iijima sunago
    I posted a photo of in the "Bark" thread
    showing the remnant diseased wood of the
    right fork of the tree that was decimated
    into nothingness in three years time from
    its bout with Tight Bark and Verticillium
    alboatrum
    . What is not shown is that
    the left fork of the tree lived for another
    ten years before it succumbed in the
    same fashion. When we buy a tree
    that is fifteen years old to start with,
    have it for another 20 years and then
    see it decline in three to ten years
    like a metastasis cancer, we lose
    a lot of faith in these plants that
    we may have them for 40 and 50
    years or be able to pass them
    along to our grandchildren and
    beyond. Much of the time our
    initial feeling that these trees can
    live for 50 years and more is being
    unrealistic. Some varieties of
    palmatum type Maples have had
    a history of only being alive for
    people for roughly 15-18 years
    anyway. Some varieties of
    dissectums may have only had
    a life span for 7 years and less
    for several years. Two of them
    were the old Filigree and Silver
    Lace, no matter if they were on
    their own roots or came about
    from seedling selection. After
    years of selective grafting we
    were able to induce more vigor
    into the plant, lessened the
    amount of Verticillium alboatrum
    in those plants and felt that an
    average Maple could live for 15
    years and more for most people.
    Having this notion that these
    Maples could live that long for
    some people was a major
    accomplishment for the nurserymen
    that spent a lot of time working on
    those two Maples in order to perpetuate
    them long enough to sustain a viable
    source of wood for propagation over
    time. No doubt a lot of Maples died
    out like the old form ribbon leafs
    because we failed to graft them at
    a time when we could have helped
    prolong their longevity. We lost out
    because some of us felt that these
    Maples were destined to have short
    term lives and just accepted that we
    would not have them long as collection
    plants. There was not even a belief
    that someday these trees could
    become a viable landscape plant
    for people and if they could not live
    for any length of time in a landscape
    they were not considered to be a
    worthwhile project to even propagate
    in a nursery for resale. Nothing has
    changed in the last 50 years or so
    in the nursery industry, if you buy
    a plant and lose it in one to three
    years time you will be hesitant
    to buy another plant again from
    that same nursery. It is unfair
    to those nurseries offering Maples
    that are known not to live long for
    people but at the same time we
    all are hoping that some of them
    will live a long time for someone.
    It is seeing that one Asahi zuru
    and Garnet live for 40 years that
    keeps the purist and professional
    nurserymen motivated and “remain
    in the game“.

    Off-topic: off on a tangent again below.

    A quick comment about whether
    to water or not during freezing
    soil temperatures. Depending
    on our soil substrate, soil mix
    if you will, I want moisture in
    the root zone, even when the
    root balls are frozen solid. We
    tend to forget that the water
    mold fungi are held in check
    in freezing temperatures. We
    may see some symptoms of
    the water molds in a thawing
    out for in ground and container
    plants. If given a choice of having
    a root system become decimated
    or severely freeze burned over a
    long period of time or having a
    tree be subjected to a water mold
    fungus, I'll deal with the fungus
    any day of the week. Yes, there
    are some soil drenches that can help
    for the fungus but at the same time
    we have to be careful that we don't
    harm the root systems ourselves
    in our tree protective maintenance.
    Much of the time we kill off root
    systems by not knowing when
    and when not to apply a fungicidal
    soil drench. An insecticidal soil
    drench for the root weevil may be
    necessary in areas that are prone
    to have significant infestations but
    even then an application during the
    Fall and Winter months in most areas
    is not recommended. Spring applications
    when the roots are functioning is probably
    the best time of year for a soil drench
    application, in areas where it is felt
    to be necessary but in most Maple
    growing areas it is not going to be
    required and not even needed at
    all.

    It is wishful thinking that a Copper
    based fungicide will help for quick
    decline - Verticillium dahliae but
    a soil drench for Verticillium alboatrum
    and in regions that are known to be
    susceptible to the many forms of
    Pseudomonas syringae, can help
    protect the plant, at the expense
    of some root system development.
    (Even here the Cooperative Extension
    will recommend using a Copper based
    fungicide as a soil fumigant for in
    ground nursery trees, not to suppress
    the bacterium but act as a preventative
    to limit the spread of the bacterium from
    infected trees to non infected trees only).

    Jim
     
  4. whis4ey

    whis4ey Well-Known Member 10 Years

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    Location:
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    Thanks for the comments
    My own idea is that there must be some root problem, brought on by environmental stress. I hardly ever fertilise (maybe I should?) because I seldom grow my maples in pots. Gardening here in heavy undraining clay can cause problems, but it is unusual to see such a mature tree suffer. It and now a 'A P Taylor' has the leaves drying up and dying. The latter tree was just bought last year and planted high in the ground to help with drainage. We have had little or no sun but plenty of winds at times and loads of rain
    All in all it hasn't been a good period for my trees
     
  5. whis4ey

    whis4ey Well-Known Member 10 Years

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    Location:
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    The strange thing here is that the two Garnets are recovering, but Oridono Nishiki has joined the 'dying' plants, which are now all variegated varieties ... Asahi Zuru, Oridono Nishiki and Taylor
    I am ''''''baffled''''''''
     

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