I'd love some advice on treating blackspot. I tried to control it organically last year and it got totally out of control. Even my disease resistant varieties have it (but are responding to treatment more than the non resistant ones). This is what I'm doing so far:
-spraying wih neem oil weekly
-collecting all diseased leaves before they fall
-keeping pruning instruments clean
-cornstarch, garlic, and bananna peels in the soil
-keeping plants fertilized with Rosetone
Should I use something stronger than Neem either instead of or in addition to it?