Thank you. So the chances on knock out roses in Texas are slim?

I mostly just remove the whole bush, but in one instance I tried to remove the cane, which seems to have worked. It is an Out of Rosenheim. I found signs of infection at the tip of the cane, and removed that cane. I also gave the entire bush a severe haircut, hoping to rid of earlier infection. It has been two years and no problem so far (and knock on wood). All the search I am aware of says that pruning does not help, though.

One of the problems with practical experience here is that those cases where rosarians report that severe pruning worked may have been on plants that never had rose rosette virus but showed symptoms from herbicide damage (if molecular testing was not done).

If only one cane shows (apparent) new infection at the tip, I recommend cutting the complete cane off (particularly on a large bush such as a climber). But, until more complete studies are available, I consider this action only as a "maybe".

The other problem is that we just moved into this house, so I have no idea how long it's been there. I may try removing the canes as an experiment, bit it sounds like it won't work.

Thank you all for sharing your experiences!

It does work on some roses. In my gardens it seldom worked on Hybrid Teas because the fall infections didn't show up until the following spring.

I have roses that got it fifteen years ago, I cut out the cane that first showed it and I recognized the problem early and fifteen years later, the rose is healthy.

Fortunately for me and my roses, Henry's herbicides never were used near my roses. After all, Herbicides......killl.....duh.

E W do you have any photos to share. If it is indeed rrd and it is showing extreme infection on more than one rose. Then it is to late to try pruning. In my case it works best in the very early stages at the first sign of unusual growth.

The other possibility is herbicides were used before you moved in.

My success rate with pruning is about 50/50. It CAN definitely work. It takes time for the infection to become systemic through the entire plant. As mad_gallica stated, the earlier you catch it, the better the chance of saving the rose. Ann's comment about hybrid teas is the flip side of that. Autumn infections are the least likely to be found early, therefore the most likely to be fatal. The roses that show symptoms in the earliest Spring growth (from an Autumn infection) are goners, in my experience.

I've saved Golden Celebration, Prosperity, and Mme Lombard, but lost Drop Dead Red, Tranquillity, Night Owl and Cardinal de Richelieu. This is just in the last three years. Until then, I lost ALL the infected plants, since I didn't know there was even a possibility of saving them.

I'm currently watching the old garden roses Arethusa and (in commerce as) Park's Yellow Tea Scented China. Fingers crossed...

I'm not going to lie. I didn't know this was an issue until yesterday. I've enjoyed taking care of roses for the past few years and thought some roses just faded out eventually. I never knew what caused the witches broom effect. So I've been cross contaminating for a little bit. I'm investing in some bleach and have new loppers on the way. I really don't want to dig them up and try to figure out what to put there instead.

I had read that it has a rather long latency...if you prune, it might go away for some time and then resurface. Although 15 years , as in Ann's experience, would make me quite confident it was gone. I cannot say from personal experience as I've always shovel pruned...I don't want to worry about circulating in a live plant with the possibility of infecting others.

BenT,

A part of my bravado comes from having a binoc microscope and being surrounded by hay fields.

I can check sick and not sick roses for the vector mites and I used to check every time I removed part of a rose. The Hay Fields come into play because that's where so many predaceous thrips hang out- they are what eat the regular thrips ( thrips that first appear in spring and then magically the population drops off.....except it's not magic, it's predators))

There are a lot of strange things out there. I was fortunate to sit with Jim Amrine and ask lots of questions.

On most all of my 'sick' roses, all I see are carcasses. Unlike some multiflora where the vector mites have been counted in the hundreds. (Indiana and Iowa)

The following statement was made by someone who lives in Tennessee:

"Fortunately for me and my roses, Henry's herbicides never were used near my roses. After all, Herbicides......killl.....duh."

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H.Kuska comment: yes, herbicides used at label concentrations sprayed directly on roses will probably kill the roses, but that is not what is being considered when rosarians are talking about herbicide damage due to drift. This type of herbicide damage is normally concentration dependent and can be due to mutations in the plants genes.

The reason that many weeds are becoming "immune" to common herbicides is a subject of intense interest to plant scientists. Fortunately this July 20, 2017 reviewed published research paper is available free. The introduction section should be useful for a historical review of the field.

Title: "Herbicide injury induces DNA methylome alterations in Arabidopsis"

https://peerj.com/articles/3560/

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Apparently, off site drift of dicamba herbicide is becoming a major concern in Tennessee.

https://www.google.com/search?newwindow=1&site=&source=hp&q=tennessee+dicamba&oq=tennessee+dicamba&gs_l=psy-ab.3...1585.18080.0.21815.18.17.0.0.0.0.199.1797.9j8.17.0....0...1.1.64.psy-ab..1.15.1500.0..0j35i39k1j0i67k1j0i131k1j0i20k1j0i22i30k1j33i160k1.g16Axu8MqIs