Ten rose bushes ranging from hybrids to standard. Fungus, rust, black spot--best method and product for treatment and prevention?
Black Spot, Etc. On Roses
The best fungicide I have found to stop black spot in its tracks is called Mancozeb. I get it from http://www.rosemania.com . A bottle of it lasts a long time so the price is not that bad. I use it if I have black spot get started and cannot gain control. As my main fungicide I use a product called Green Cure. I have zero problems with any funguses if I keep the rose sprayed with it at no more than 14 day intervals. Two scoops of it per gallon. A little scoop comes in the tub of product and you use the big end of the scoop.