What is this, will it spread to maples, & what kills it?

Discussion in 'Maples' started by winterhaven, Jun 24, 2009.

  1. winterhaven

    winterhaven Active Member Maple Society 10 Years

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    Location:
    Western Washington, USA
    I've got three disease issues right now...

    A. The first white stuff I suspected was powdery mildew - but I've never seen it in person (to my knowledge) so I asked a person at the local nursery. It's also on two azaleas in a more advanced form. Nurseryman's diagnosis: azalea gall.
    1) Is this Azalea Gall
    2) Will it spread to maples
    3) Will the cure for it be bad for the soil - I had planned on putting in my new, large Purple Ghost right next to this thing.

    B. The next stuff is on an Arbutus Marina.
    1) What is it?
    2) Will it spread to maples?
    3) What is the treatment?
    4) Is the treatment harmful to maples?

    C. Please see my post in Peaches and Cream at http://www.botanicalgarden.ubc.ca/forums/showthread.php?p=207778#post207778

    Any advice is highly appreciated.
     

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  2. maf

    maf Generous Contributor Maple Society 10 Years

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    Location:
    Northamptonshire, England
    Hi winterhaven, my thoughts on this:

    A and B look like fungal problems, knowing the name is not too important as the best method of control is to remove and burn the affected foliage to prevent the spores spreading.

    A - I can't see any galls so maybe it is powdery mildew rather than Azalea gall, or maybe they have just burst already. They are both fungal diseases anyway.

    B - likely a rust of some type.

    These pathogens are usually troublesome if a shrub is too dry at the roots (has there been much rainfall?) or malnourished etc; a water/feed/mulch would be good. I wouldn't turn to chemicals at this stage.

    As to whether they can affect maples, that is hard to say as some only live on a specific host species while some are less picky, but remember they are usually only a problem for dry or weak trees.

    For C I would remove any blackened tips and wait and see at this stage. Hopefully just the stress of transplanting as you thought.

    Good luck.
     
  3. winterhaven

    winterhaven Active Member Maple Society 10 Years

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    Location:
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    Not much rainfall at all - we've set a record number of days without rain. I thought I was keeping up on the watering, but now that I think about that area more carefully... yah, I can see it needing more water.

    My concern is that I want to put in a tree near there and I'm worried the transplanting will weaken it. Hmm. To heck with it. I want to put my tree in the ground. I'm going plant it early tomorrow morning while it's still cool and get it in the ground.

    I hope so. Thanks. I appreciate the feedback and thoughts.
     

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