I tried using a 10% bleach solution to clean my flower buckets in my shop, and now I'm seeing weird spots on the rose stems. | Florists - Freelance Forum - The Community for Independent Professionals
My buddy at his nursery had the same thing happen last year. He used a strong bleach mix on his buckets and it left these chemical burn marks on all the hydrangea stems. The spots looked almost rusty. He switched to just using a little dish soap and really hot water for cleaning, and it stopped completely. Those bleach marks never really went away on the affected stems though. It can really mess with the plant tissue.