Q.black spots on roses
I purchased Mancozeb fungicide to stop the black spots on my rose leaves. It came in a pint bottle and the instructions just say to spray it on. There were no instructions that says just spray it on or dilute it. So I put it in a spray bottle and it wouldn’t spray. Then I bought another spray bottle and it is still too thick to spray on. How am I supposed to put it on if it is too thick???
Am I supposed to dilute it or what/how to apply.
I can't speak to the products that you have or any application instructions; you will need to contact the manufacturer for any questions.
However these links are what we suggest for treatment of Black Spot disease.