White spots and holes in leaves.
I am a beginning gardener in Indiana and am trying to grow everything organically. I have four rosebushes that are loaded with blooms, but the leaves don't look healthy. Lots of them have grayish-white splotches and holes in them. Many of the holes are a bit heart-shaped, or they have two humps. I have not seen any bugs on the plants at all, but I am assuming it must be either bugs or disease that is injuring the leaves. I had this same problem on another rosebush a couple years ago and never figured out what the problem was. Can anyone tell me what might be causing this damage, and also how I might be able to get rid of it without using chemicals?