A handful of rose bushes came with the purchase of a house almost 3 years ago. They had been neglected in recent years but gave us a beautiful display the 1st summer. Not being an expert myself I researched and followed recommendations. I pruned in February cleaning pruners with alcohol between bushes, fertilized when suggested and cleaned debris accumulated under them. Last summer the buds were blackish and never opened on the white rose bush. I thought maybe botrytis and treated with pre-emergent fungal spray in early Spring. The bush is doing better but roses and buds have bruised looking rims. I checked for thirps and didn’t find any. Do you have further advice or action corrections to suggest? Seems they were better off with the neglect.
Thank you for your question. The rose appears to have botrytis, and you took good corrective measures. As the following diagnostic guide indicates, fungicides are of little use: https://pnwhandbooks.org/plantdisease/host-disease/rose-rosa-spp-hybrids-botrytis-bud-twig-blight So, keep on doing what you’re doing (minus the fungicide), otherwise neglect judiciously, and realize you are in the World Fungus Capitol. Good luck!