Rose Rossette Disease - Ask Extension
I have three plants of knock out roses planted in a row, two of them shows some sort of abnormality, on their leaves and blooms. One of those two show...
Knowledgebase
Rose Rossette Disease #867409
Asked May 07, 2024, 11:57 AM EDT
I have three plants of knock out roses planted in a row, two of them shows some sort of abnormality, on their leaves and blooms. One of those two show the same things last year as well. I am not sure if this is RRD or just pesticide of just new growth. I’m attaching pictures for you to see them.
Thank you!
Wake County North Carolina
Expert Response
Hello,
There are a couple of main indicators that your rose bush has rose rosette disease. The first thing you may notice is that your rose is growing in an unusual way. By this I mean that new growth is clustered together in a bunch rather that what you are used too. This unusual growth is called a witches broom and the shoots in this growth area tend to be red in color. The second indicator is that you will notice new growth shoots have an abundance of thorns. Yes, roses have thorns, but normally not this many thorns. Once you see it you’ll likely think “I don’t remember seeing that many thorns on a rose bush before.” And you would be correct. It can be an impressive number of thorns.
While these two symptoms are clear indicators of the presence of RRD (rose rosette disease), if you would like confirmation, you can cut off one of the symptomatic shoots, wrap it in dry paper towels, and place it in a sealed plastic bag and bring it to NCSU PDIC clinic. Here is a link for details;
https://pdic.ces.ncsu.edu/how-to-submit/
Also, you can wait and see if the new growth turns green. If it does and you do not see an unusual amount of thorns, ( which I do not in your images), you probably do not have rose rosette disease. I have one rose bush that does the same but it doesn't stay red so I am watching it just in case. If it is RRD then you will need to dispose of it so it doesn't effect another rose in the area.
Here is a link for more information;
https://hgic.clemson.edu/factsheet/rose-diseases/
Good luck and let us know if you have any other questions.
There are a couple of main indicators that your rose bush has rose rosette disease. The first thing you may notice is that your rose is growing in an unusual way. By this I mean that new growth is clustered together in a bunch rather that what you are used too. This unusual growth is called a witches broom and the shoots in this growth area tend to be red in color. The second indicator is that you will notice new growth shoots have an abundance of thorns. Yes, roses have thorns, but normally not this many thorns. Once you see it you’ll likely think “I don’t remember seeing that many thorns on a rose bush before.” And you would be correct. It can be an impressive number of thorns.
While these two symptoms are clear indicators of the presence of RRD (rose rosette disease), if you would like confirmation, you can cut off one of the symptomatic shoots, wrap it in dry paper towels, and place it in a sealed plastic bag and bring it to NCSU PDIC clinic. Here is a link for details;
https://pdic.ces.ncsu.edu/how-to-submit/
Also, you can wait and see if the new growth turns green. If it does and you do not see an unusual amount of thorns, ( which I do not in your images), you probably do not have rose rosette disease. I have one rose bush that does the same but it doesn't stay red so I am watching it just in case. If it is RRD then you will need to dispose of it so it doesn't effect another rose in the area.
Here is a link for more information;
https://hgic.clemson.edu/factsheet/rose-diseases/
Good luck and let us know if you have any other questions.
