I have a large tulip tree (liriodendron tulipifera) under which I have planted many varieties of hostas. There seems to be some liquid dropping from the tulip tree which has covered the hosta leaves with black spots. At times the secretions are shiny. I've noticed the same problem in my back yard with wine berry leaves which are under another tulip tree.
Does anyone know what causes this problem? Is it an infected limb or just a natural situation with tulip trees. Until I had invested a lot of money and time into the hosta garden I had not noticed this.
Also, does anyone know of a safe way to clean the hosta leaves? They look awful.