What is wrong with my delphinums? they all live in the same area and have black spots all over the lower leaves! Not aphids, I checked, but now a later-growing delphinium is showing signs of it on the new growth. Not Good!! What is it and how do I get rid of it? Will It spread??
It's a fungus, you need to remove the bad leaves(put them in a bag and throw in the garbage and wash your pruners and hands). Then spray with a fungicide containing chlorothalonil, like Daconil. You will need to spray at least twice, 7-10 days apart.
