Sunday, September 29, 2013

Rose Rosette Disease in my garden

Rose Rosette Disease (RRD) is a rose virus that has invaded my garden.  It is spread by mites blown by the wind from other infected roses. The first indication is new growth that is not typical for that rose, it may be unusually thorny with a red coloration and a witches broom appearance. I suspect the source are roses in a city street median strip about 500 yards from my roses. The virus is systemic so it will eventually affect the entire plant though at first is is just a single branch. This is what RRD looks like on a 10 year old knockout.
This is a close up of RRD growth on this bush.
This is what normal growth looks like on this Knockout.
Next I'll show what appears to be RRD on roses in the garden. The first is The Dark Lady a David Austin rose. It is one of my favorites. First what appears to be infected new growth and then normal growth on the same bush.
No doubt in my mind this rose is infected. I did remove the branch to the bud union. Some rosarians say that if removed early enough the virus may not have spread. The Dark Lady is a sultry red rose...the name fits the rose. I will definitely replace this one.
The next rose affected is ST. Patrick a hybrid tea. Definitely RRD...note the abnormal thorny stems. I cut this limb.
This is RRD on ST. Swithun, a David Austin rose. I cut this branch all the way back.
More RRD on American Beauty, a hybrid perpetual. I'm not thorns and not really witches broom. But I cut it off.
This is Cornelia a hybrid musk with strange growth. Is it RRD...when in doubt cut it back.
Finally new growth on Erfurt, another hybrid musk, that I don't believe is RRD. This is the only branch that I didn't cut.
Time will tell if the virus has spread or if I cut it early enough. If I see RRD type growth reappear on any of these bushes I plan to remove them. I'll bag the debris and send it to the land fill. I'd like to burn it but open burning in the city is not a good idea.

I didn't get a pic of the cut flowers this week but here is an arrangement.


  1. I am so sorry that RRD is causing havoc in your garden, and hope that your early detection and treatment will stop the spread of this dreadful disease.

  2. Your Erfurt also has RRD. Look at the very short internodal distances below that bud. Also the mottle pattern on the leaves. Also the asymmetry of the leaves as well as the leaf margins. I've grown Erfurt for almost a decade and that's not what Erfurt is supposed to look like in the fall.

    Ann Peck

    1. Ann, Thanks for your assessment. I'll cut it back to the bud union tomorrow.

  3. With so many infected roses, I wonder how you determined that you do not have herbicide damage? In addition to the cane cutting to the ground step that you mentioned, I recommend a thorough watering to remove any possible herbicide from your soil.

    1. Henry, two of the roses exhibiting strange growth could be from a herbicide that I used the year before planting to kill the bermuda grass. But herbicides were not used near the other three. The infestation is less than 5% of the roses in the garden but it will increase since all of the roses in city median strips are infected. Until they are removed I expect to see a dramatic increase. One local nursery did not sell roses this year since all of their landscape plantings were infected and they could not guarantee a virus free plant.

  4. Three years ago we planted 6 new rose plants. It wasn't long before we observed that odd witches broom on new growth of one of the roses. We immediately removed the entire plant, bagged and disposed of it. We were very lucky. The other roses thrived. How have your roses fared since this September post?