Bordeaux Mixture / Copper Sulphate for Japanese Maples?

Discussion in 'Maples' started by Kanuni, Dec 12, 2011.

  1. Kanuni

    Kanuni Active Member

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    Here, the common practise is to spray almost everything with copper sulphate / bordeaux mixture as a preventitive measure in the winter months. I guess it also prevents early awakening of the tree if the weather goes hot (correct me if I am wrong please).

    Last winter, my gardener sprayed everything with bordeaux mixture, including the japanese maples twice with one month interval. This year, before letting him do it, I would like to know first whether this is a correct thing to do and whether it can be harmful in anyway for my trees, especially the japanese maples.

    What do you think about this? Should I go ahead and spray them? If so, when and how many times? Do you advise anything else instead of bordeaux mixture / copper sulphate to use in winter as a preventitive measure, or anything to be used in addition to it? Since my climate is at the edge for japanese maples, I would like to make sure I do everything correctly. (I am in Izmir Turkey, next to the mediterranean sea. USDA zone 9b)

    Thanks in advance.
  2. mr.shep

    mr.shep Well-Known Member 10 Years

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    San Joaquin Valley, California
    Unless you are in an area that is known to
    have Spring issues with blight or blast forms
    of Pseudomonas and perhaps Anthracnose,
    then applying a topical fungicide or bacterial
    spray is not recommended for the palmatum
    type plants. I've never used a fungicide spray
    on the palmatum type Maples and much of the
    time advise others not to use the spray where
    they are growing these Maples.

    Yes, there are some areas that may want to
    use a preventative spray for Spring forms of
    Powdery Mildew, Downy Mildew and water
    mold fungi in cooler, wetter and humid Spring
    climates but that generally is a case by case
    situation, depending on how frequent, how
    often, these issues arise and is not the norm,
    not an issue at all around here, for warmer,
    less humid and drier Spring climates.

    [Should someone be in an area whereby there
    are prevalent or intermittent issues with Deep
    Bark Canker or Shallow Bark Canker of Silver
    and Sugar Maple, then it may be advisable to
    use a Copper sulfate spray as a preventative.]

    Be very careful mixing Copper sulfate with a
    light or horticultural oil as the oil can cause
    wood burn for many Maples. Mixing Copper
    sulfate in water is the preferred method of
    choice. Should you want to use this fungicide
    as a preventative spray for the leaf spot, both
    fungal and bacterial, diseases in the Spring
    in areas that are known to be susceptible.

  3. ksc

    ksc Member

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    Hanson MA USA
    Here in MA, USA, we have a terrible problem with winter moths. The suggested treatment is a dormant oil spray before they hatch.The timing of the late winter/early spring treatment is area dependant. After/during leaf out I spray with a Spinosad based product once a week untril they stop eating (usually the beginning of June here in zone 6).
  4. Kanuni

    Kanuni Active Member

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    mr shep, thank you for your post. The problem is, there isn't any knowledge about issues in spring for maples here. I have in total 15 japanese maples, 1 small sugar maple and 1 small red maple, I probably have 95% of all japanese maples in home gardens in this area... (The population of my city is 3.5 million btw) I guess that in future, the number of japanese maples in gardens will increase once people realize that it is doable but until then there is no data nor knowledge about the problems they face in spring.

    The winter and early spring is wet here, with plenty of rain. For fruit trees, copper sprays are recommended here and mostly the trees are sprayed with bordeaux mixture once when the leaves drop and once before bud break (I think). Last year I let my gardener spray all my trees with bordeaux mixture including the japanese maples because of this...

    As per your recommendation about not using sprays, I will not spray my japanese maples this year (also having read about its dangers, I will not spray my fruit trees either and see what will happen). Is there anything else I can use that does not harm the trees and/or environment? For example I like to use a product made only of ws sulphur on my roses (I hate chemicals) for powdery mildew and I haven't had much problems with powdery mildew eventhough many of my neighbors did. Can I safely use this on maples as well (monthly maybe?) after spring when they have leaves? ws sulphur applied on leaves should be safe right? Anything else do you suggest as preventitive measure both in winter to be applied to the bark and in spring to be applied to the leaves?
  5. mr.shep

    mr.shep Well-Known Member 10 Years

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    San Joaquin Valley, California
    there isn't any knowledge about issues in spring for maples

    There is little cultural information on palmatum type Maples
    most anywhere - offline or online. I've already posted more
    general information on some diseases in this forum than you
    will find in any book. Some people feel that Powdery Mildew
    is an issue for them when in reality the real culprit may be
    Downy Mildew in some areas. Most people do not equate
    Anthracnose as being an issue but it can be with some of
    the palmatum type Maples, I've seen it in Oregon and even
    in some locations in the San Francisco Bay area - East Bay,
    West Bay, South Bay and Marin. Tar spot can be a real
    nuisance along the Northern Coast of California on Maples
    both palmatum types and native Big Leaf Maples. Just to
    name a few instances.

    [I will not spray my fruit trees either and see what will

    This may be a huge mistake. Fruit and nut trees are in my
    expertise area for many years. If you are in a location in
    which foliar diseases are an issue such as Peach Leaf Curl
    or worse yet Brown rot or Hull rot then it may be imperative
    to spray your trees. I manage Fruit, Pome and Nut trees
    in a commercial operation. There is no way that we would
    not spray our trees every Spring with a light oil and either
    Copper sulfate or a Copper hydroxide spray as a dormant
    spray and/or a pre-popcorn to early bloom spray.

    Sometime go to this web site and read the recommendations
    for various plants. Keep in mind, that although I am partial
    in my viewpoint, the content therein is considered by many as
    the world standard. The whole premise is that we do not spray
    a pesticide unless it is absolutely necessary. In commercial
    operations there is a specific need to use fungicides for certain
    crops. Even certified organic growers are able to use some of
    these same sprays if need be. Where I draw the line is in the
    use of herbicides, soil fumigants and insecticides and am very
    selective about using them, much more so than most people.]

    Home Page - UC Statewide IPM Program:

    As far as using a dormant oil for specific overwintering insects
    then the use is applicable where needed. The use of oil sprays
    for most people with Maples generally is not needed. All I did
    was point out a caution and to further that caution it is my
    recommendation to only use an oil spray while the Maple is
    dormant - Winter to pre bud swell in the Spring.

    Last edited: Dec 14, 2011

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