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kentucky_rose

Identify problem

I have had a lot of this problem this year.

Picture #1

Picture#2

Picture #3 other side of first picture

Any insight into cause, prevention, and treatment would be appreciated.

Comments (16)

  • 10 years ago
    last modified: 10 years ago

    Can you give us close-up photos of the areas? Could be cane borers, but can't tell from these photos. Also, what varieties, anything up with weather, etc. CSI-level info.

    kentucky_rose zone 6 thanked diane_nj 6b/7a
  • 10 years ago

    i am sad.

    kentucky_rose zone 6 thanked Christen Genova
  • 10 years ago

    Diane and Nippstress, I do have cane borers and I have cut roses and discovered a hole in the stem that I cut. So they get in other ways than just a fresh cut, which I try to seal with Elmer's exterior wood glue and I have even tried a green adhesive acrylic paint from Michael's. Winter damage, not pruning far enough down the stem makes sense. But why are the new laterals dying? Borers? Don't remember which plant I cut the stems from in the above pictures. My leaves have been dropping, too. They look naked. Not all are due to BS and spider-mites. They grow back and then begin dropping, again. Could that be caused by winter damaged stems?

    Close-up of above picture.

    Red Intuition similar problem.

    Snuffy with similar problem. It is a BS magnet! TIA.

  • 10 years ago
    last modified: 10 years ago

    I find my HT roses grow better if I prune away those thin laterals. I don't care if my HTs get pruned down to a single cane--I just wait for mine grow new ones to replace what I've removed in the early Spring.

    kentucky_rose zone 6 thanked zack_lau z6 CT ARS Consulting Rosarian
  • 10 years ago

    Zack, I think the thin laterals were new spring growth and some canes have gotten thinner, nobbier over the season.

  • 10 years ago

    I find also helps to cut canes to the same length during the early Spring pruning--the taller canes grow faster and the short ones get left behind--better to cut the short ones all the way back to the bud union.

    kentucky_rose zone 6 thanked zack_lau z6 CT ARS Consulting Rosarian
  • 10 years ago

    Zack, thanks. I am guilty of the above.

  • 10 years ago

    The weather might be part of the problem. When the temps soared out of control here all my plants displayed unusual growing patterns, blooms and problems.

    Do you have grasshoppers? This year pests have been a constant problem in my garden. Also, this years weather patterns are a breeding ground for disease. Do you have a spray program?

    kentucky_rose zone 6 thanked carlotaroser
  • 10 years ago

    Carlotaroser, I have seen a few grasshoppers, but problem has been ongoing this season. I spray with fungicides and insecticides. We have had a wet season and the temps have been in the nineties some days. I was wondering if some of the leaf drop was slugs?

  • 10 years ago
    last modified: 10 years ago

    You may carefully inspect the dropped leaves for insect damage or disease.

    kentucky_rose zone 6 thanked zack_lau z6 CT ARS Consulting Rosarian
  • 10 years ago

    This morning I cut and examined some canes on Joy and problem was cane borers. I glue and use insecticide, they still get in. Any suggestions?

  • 10 years ago

    I seal all of my cuts as well and they still get in. I seldom able to find any entry point. They pierce the cane somewhere and lay the larvae. But it's not where I cut and glued.

    kentucky_rose zone 6 thanked Patty W. zone 5a Illinois
  • 10 years ago

    I agree with Cynthia. I'm still cutting off canes like that too. They were damaged some over winter but still looked green in the spring so I left them thinking they were OK. However, being already weakened, they've slowly died off.

    kentucky_rose zone 6 thanked seil zone 6b MI
  • 10 years ago

    Looks like a major problem of cane borers. The more I look, the more I find.

    i am having to go way down the cane to remove all of the borers. Below is a picture of just removing a spent bloom.

    If you enlarge picture, you can see the white larvae.

  • 10 years ago

    Since the blue cups help with thrips, would white cups help with the sawflies?