QuestionsHow to growTrees and ShrubsPests and DiseasesBlack spots on leaves 0 Vote Up Vote Down lorraine ocarroll asked 16 years ago Overnight my honeysuckle became covered in large black spots. Soon after, my nasturtiums began blackening and leaves withered completely. Now see blackening on oregano and potatoes. 1 Answers 0 Vote Up Vote Down Gerry Daly Staff answered 7 years ago There is no disease that can affect that range of plants as they are all from different families. The sudden impact would point to physical damage caused by weather … strong winds, a touch of frost(though unlikely) or hail damage.