Blossom end rot is a physiological disorder in plants that can be identified when the lower ends of squash turn brown and fail to develop properly. This disease also commonly affects tomatoes, peppers and watermelons.
Blossom end rot is frequently caused by low calcium in the soil or low pH levels. Uncommonly high or low temperatures and drought can also cause blossom end rot. This disorder can not spread between plants, but it can appear sporadically or be a persistent problem until the underlying causes are corrected. Having garden soil tested before planting is recommended to prevent the onset of blossom end rot. Additives can be mixed into the garden soil if test results indicate that nutrient levels are low.