Knowledgebase
Pink and Brown spots on roses #835913
Asked June 16, 2023, 8:54 AM EDT
Hello. I'm writing to ask for help in identifying these odd spots on my roses.
The pink spots tend to show up on my white roses. I've had them before.
The brown spots are new for this summer. They appear on the petals of blooms that are still growing, making them look like they're wilting even if they're new blooms.
The roses are watered regularly with soaker hoses and fertilized with a rose fertilizer. They were planted in compost with cow manure and myko fungi. I am otherwise successful in growing roses, both of the English shrub variety by David Austin Roses, and floribundas/hybrid teas.
I would appreciate advice. Thank you!
Kalamazoo County Michigan
Expert Response
I just went out to remove the two roses with the pink spots and was shocked to discover that the spots had spread to all the other blooms among the three shrubs. I did some deadheading last night; the spots were not there.
Incidentally, I attempted to treat the brown spots with a BioAdvanced 3-in-1 spray.
Thanks for reaching out with this question. It looks as if you might have gray mold or Botrytis blight on your roses. This pathogen has a wide range of temperatures at which it can develop and if it's been humid in your area, that may explain why you are seeing all of the sudden. You should be sure to clean up any of the infected petals that may have fallen around your plant to prevent further spread. You may also want to back off on the fertilizer, since too much nitrogen can lead to fast, floppy growth that is more susceptible to infection from this type of pathogen. Other that that, you should see this problem clear up as we move into the drier conditions of summer. Here is a link to a great resource on rose care from the University of Maryland.
https://extension.umd.edu/resource/rose-identify-and-manage-problems
Thank you very much for getting back to me with this helpful information. Much appreciated.
