QuestionsHow to growVegetable GrowingWeeds, Pests and DiseasesProblem with potato plants 0 Vote Up Vote Down Marietje Murphy asked 16 years ago a few of our potatoe plants have died, the stalk has gone black at the bottom 1 Answers 0 Vote Up Vote Down Gerry Daly Staff answered 7 years ago This is blackleg disease of potatoes. Remove and destroy the affected plants and there are usually just a few. It is a seed-borne disease and purchased seed potatoes are more likely to be free of the disease, though not always unfortunately.