Diseased roses?? - Ask Extension
My roses are not looking very healthy this year. They had suffered through black spot and some have had powdery mildew in the past, which had both be...
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Diseased roses?? #324497
Asked May 23, 2016, 9:27 PM EDT
My roses are not looking very healthy this year. They had suffered through black spot and some have had powdery mildew in the past, which had both been eradicated. All the canes were cut down in February and everything has grown back with a vengeance, but the buds are molted and unhealthy. I have never had blooms that looked this bad. Are my roses diseased? What can I do to improve their health?
Clackamas County Oregon
Expert Response
Thanks for your question about roses and the photos. One can generally tell a lot about rose health by looking at the foliage, and the foliage on yours looks really good.
A couple of things could have happened to the blossoms. First, we've had some days of unusually warm weather -- the kind that hurriedly forms buds -- followed by several cool days -- when the buds' growth slows tremendously. If cool, rainy weather lasts a while, those buds may not open.
Second, the buds look like they may have been hit by hail.
If I were you, I would remove the injured blossoms by cutting their stems in the normal way and wait for the next wave of blooms.
That being said, Oregon State University Extension has a wealth of information on rose care. I am attaching a two page overview which has additional links for more information. http://extension.oregonstate.edu/mg/metro/sites/default/files/Rose_care.pdf
Good luck.
A couple of things could have happened to the blossoms. First, we've had some days of unusually warm weather -- the kind that hurriedly forms buds -- followed by several cool days -- when the buds' growth slows tremendously. If cool, rainy weather lasts a while, those buds may not open.
Second, the buds look like they may have been hit by hail.
If I were you, I would remove the injured blossoms by cutting their stems in the normal way and wait for the next wave of blooms.
That being said, Oregon State University Extension has a wealth of information on rose care. I am attaching a two page overview which has additional links for more information. http://extension.oregonstate.edu/mg/metro/sites/default/files/Rose_care.pdf
Good luck.
