what causes grayish color on leaves of tomato bush?
My tomato bush is in a container. After the first harvest of tomatoes, all the leaves have turned to a grayish color, yet still producing fruit.
Sounds like powdery mildew. This article tells you more about the disease, and organic control methods. http://www.longislandhort.cornell.edu/vegpath/photos/powderymildew_tomato.htm