Why Are Some Radishes Black Inside?

Radishes are crisp and tasty, but some of them are black or hollow inside. The black is caused most probably by black-rot disease. This disease can affect the leaves, and the actual radishes: the leaves develop black spots and black veins and the radishes turn black inside, then become hollow and lose their good taste. Radishes may also become black inside if they are stored in a place without enough oxygen. To protect radishes from this dis-ease, their seeds should be soaked in a chemical solution before sowing, and the radishes should be kept in a place with enough oxygen and appropriate humidity after harvesting.