Asked on Jul 12, 2013

This is a red Knock Out Rose Bush which is three years old.

Susan From ColoradoCatherine SmithTheresa Campbell


This is one of three in a r aided bed garden that is filled with mulch. This plant is the only plant that I have noticed that the thorns look abnormal. Lots of the thorns are too close together and I've noticed that the roses do not last as long.
Can you please tell me what I need to do. I thought of doing a hard prune at end of blooming season abut not sure. I have never had this before and don't want to lose them.
Thank you
Theresa M. Campbell
8 answers
  • Teresa Underwood
    on Jul 12, 2013

    this rose is unfortunately diseased and will probably die. I did googling on mine in similar state.

  • Theresa Campbell
    on Jul 12, 2013

    I thought knock out roses were disease resistant?

  • Douglas Hunt
    on Jul 12, 2013

    An overabundance of thorns is one sign of rose rosette disease. Knockout roses are not immune to the disease. You should definitely keep an eye on the plant. If it is rose rosette, there is little than can be done other than remove it:

  • Laurie
    on Jul 12, 2013

    I totally agree with Doug, you have rose rosette. While the Knockout roses are very resistance to disease, it was the first type to get hit with rose rosette here in the Dallas area. Rose rosette is spread by mites and there is no cure. You should remove your rose right away and trash it. Do NOT compost it! Here is a link about the disease:

  • Christy Necole
    on Jul 12, 2013

    Thanks for the rose rosette information I have never heard of this at all!!

  • Theresa Campbell
    on Jul 12, 2013

    Thank you very much. It looks like that is what I have on my rose bush and will have to check out the other two rose bushes next to it. Very good and informative website listed above. Thank you to everybody for helping me with my problem. I love this home talk website. It is awesome.

  • Catherine Smith
    on Jul 13, 2013

    Agree with Laurie. Pull them all up and destroy the plants. Do NOT plant roses back in the area again. No rose is completely disease resistant Theresa, but Knock Outs are tough. Unfortunately this rosette stuff is the pits. Try them again in another area.

  • Susan From Colorado
    on Oct 25, 2014

    I just found this question and I am glad I did.. I recently moved 1000 miles and had our gardener friend pot all my roses for the long trip.. within the first season I was very disappointed that they got so few flowers, but also noticed these small thorns.. by the following spring they were all dead and I have been very upset as they had very special meaning for me.. but now I know the reason they did not survive as mine were also covered in these tiny unusual thorns and I just thought maybe I needed to cut the elder branches back.. that would not have helped according to what I am reading here, so thank you all so very much.. question.. should I discard all the potting mix in the pots they are in or will that be okay to pot something different in next spring??

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