seilMI said:Lynda, there has been some research that says washing the leaves can actually help prevent fungal diseases. The thought is that it dislodges the spores so they can't take hold.
OK - here's my story. In early summer, I power washed and stained a elevated deck. I have 11 roses planted below the deck, all in a straight line. Over the summer and to date, I have sprayed the deck with water about every 2 days. Inevitably the roses get sprayed also. What I noticed, is none of the roses showed any signs of blackspot. I wish I could state that as to the rest of my garden beds as I live in blackspot heaven. It seems as though, I can attribute the "control" of blackspot to "frequent" overhead watering that does not appear to allow for the spores to fasten to the leaves. The key word may be "frequent".
The pH of my water is 7.
