I have a long winding driveway lined with oaks. I've planted impatiens there for several years. They look beautiful and they are not bothered by hungry deer or squirrels (another BIG problem), but I am tired of spending all that time and money purchasing new plants and replanting every year, so does anyone know of a perennial flower that will grow in shady areas that are deer proof? (It seems deer proof plants are also squirrel proof). PLEASE help me, otherwise I'm going to have to put rocks all over the area.