Today in the world of agriculture plants are demanding the utmost care to protect from various diseases. These diseases can create several damage to different plants & their growth.This paper characterizes different diseases of rose plants, common stages followed in plant disease identification methods. Few changes are suggested in the preprocessing stage to improve the quality of results. Lot of research is going on in this area with the help of Machine learning & Image processing. As some diseases of rose plant are common with many of the cash crops like cotton, this work can be further extended to the automatic plant disease identification method of many such plants.