Rhododendrons: shriveled new growth

Discussion in 'Ericaceae (rhododendrons, arbutus, etc.)' started by Mama Cass, Aug 6, 2005.

  1. Mama Cass

    Mama Cass Member

    Messages:
    3
    Likes Received:
    0
    Location:
    Kirkland, WA, USA
    I am a condo dweller and am trying to be a good samaritan taking care of the rhododendrons planted in our complex. They seem to be sorely negelected. I'm watering them and notice new growth on one is coming out shriveled and wrinkled. Is this a pest or a fungus and how to deal with it? Leaves on another are spotted brown.
    Please advise me. Thanks
     
  2. Ron B

    Ron B Paragon of Plants 10 Years

    Messages:
    20,624
    Likes Received:
    510
    Location:
    WA USA (Z8)
    Brown spots could be mildew, shriveling might be drought injury. When the plant gets too far dried out before being brought back with watering the new growth may have died in the meantime.
     
  3. douglas

    douglas Active Member 10 Years

    Messages:
    261
    Likes Received:
    0
    Location:
    princegeorge b.c
    hi

    any chance of a pic

    Are they close to the run off of a Cedar or Pine roof/siding

    Has your condo been worked on for the leaky condo type stuff/
    and a new stucco been done in the last 2 years

    Also check out around the drip zone of these plant and make sure that plastic was not used as a weed barrier. It may be 2 to 6 inches down below the surface.

    Regards Doug
     
  4. Mama Cass

    Mama Cass Member

    Messages:
    3
    Likes Received:
    0
    Location:
    Kirkland, WA, USA
    Thanks for your response. I hope this gives you a passable image. I also noticed little tiny white dots on many leaves on the same bush. None of the condo conditions queried in a previous response are true for my condo. Thank you, Mama Cass
     
  5. Eric La Fountaine

    Eric La Fountaine Contributor UBC Botanical Garden Forums Administrator Forums Moderator 10 Years

    Messages:
    3,494
    Likes Received:
    199
    Location:
    Vancouver
  6. GRSJr

    GRSJr Active Member 10 Years

    Messages:
    143
    Likes Received:
    0
    Location:
    Raleigh, NC
    When shriveled new growth appears here, it's due to a fly that lays her eggs in the buds. Spraying with Cygon just as the buds begin to open and then 3 weeks later gives total control here.

    I learned this from Ted Richardson, a wholesale Rhododendron grower in the NC mountains. It's been effective for the last 15 years.
     
  7. Mama Cass

    Mama Cass Member

    Messages:
    3
    Likes Received:
    0
    Location:
    Kirkland, WA, USA
    Thank you. I will give this a try, although the new growth is well out now and no longer just a new bud.
    Mama Cass
     
  8. GRSJr

    GRSJr Active Member 10 Years

    Messages:
    143
    Likes Received:
    0
    Location:
    Raleigh, NC
    Probably too late for this year then, but it may cut down the infestation next season.

    Give it a whirl nest year and let me know how well it works.

    Cygon has been removed here while they give it a new name and double the price. Perhaps other systemic insectacides will work as well, but I've only had experience with Cygon.
     
  9. Daniel Mosquin

    Daniel Mosquin Paragon of Plants UBC Botanical Garden Forums Administrator Forums Moderator 10 Years

    Messages:
    10,312
    Likes Received:
    457
    Location:
    Vancouver, British Columbia, Canada
    Hi, I apologize to all involved in this thread (and particularly Mama Cass) - I've had these photographs from the original poster sitting in my inbox for a while - I think they arrived while I was on vacation last August, and I'm only now getting to them as I attempt to slim and trim my 350+ email inbox before going on vacation again.

    Again, my apologies.
     

    Attached Files:

  10. Ron B

    Ron B Paragon of Plants 10 Years

    Messages:
    20,624
    Likes Received:
    510
    Location:
    WA USA (Z8)
    Don't know about scattered puckery leaves, but new growth with white dots in summer is insects. Look closely for bugs, like aphids. The notches in the leaves in your pictures are weevil damage.
     
  11. GRSJr

    GRSJr Active Member 10 Years

    Messages:
    143
    Likes Received:
    0
    Location:
    Raleigh, NC
    Shriveled new growth is usually the result of a fly that lays her eggs in the buds. Cygon 2E applied just as the buds are about to burst cures the problem. I got this from a commercial grower in the NC mountains, and it's worked very ewll.

    Problem is, Cygon 2E has been removed from the US and Canadian markets. I understand that Merit is the preferred replacement, but I have no experience with it yet.
     
  12. K Baron

    K Baron Well-Known Member

    Messages:
    1,032
    Likes Received:
    2
    Location:
    North Vancouver, B.C., Canada
    Are these Rhodos planted on a slope? under the building's eves? If they dry out in our dry summers, this has a dramatic effect on their growth cycle, the weevils have had their feast and will continue to do so. During the spring and summer nights, spread out a white tarp under the plant, and at 4 am, check them out, shake the branches and see how many of those weevils you have harvested! Try this on a weekly night ritual, it could only help the plants and give you an early start to your day! Try pouring cold tea baths on the new growth, the acid may be a natural cheat to arresting the mildew...well at least it,s woth a try and you can do this after your cup of tea in the morning!:)
     

Share This Page