My elderberry bush is looking sickly. Some of the leaves are healthy looking, but you can see the wilted greenery in the one photo. The flowers seem to have started, but then were stunted by something.. I don't see any bugs around. This plant is at the edge of a wooded area. Should I just remove this whole plant to reduce chance of spreading the "disease?" I prefer not to use pesticides. Looking forward to your explanation and suggestions.