Hello, I've got a terrible disease. I think it's called "Rose Mania". To say I am bewitched by roses is putting it lightly!
I currently have about 30 roses (almost all Austins) in a garden I started in 2018. Last year during a very hot and humid period, black spot hit hard. The previous year I had been able to manage BS with an organic spray. Last summer after my roses were dropping their leaves at an alarming rate and spraying was not helping, I resorted to a systemic liquid poured at the base which helped tremendously. Within a month, all of my roses were growing back their leaves. I'm thinking maybe I should just use a systemic treatment this year in early June for all of my roses. (zone 6A Massachusetts) What are your thoughts? Is it harmful to my roses in any way to use a systemic as a preventative?