Downy mildew, powdery mildew and white mold harm vegetable plants, causing blight and rot. Slime molds do not harm plants. Leaf mold, which is composted leaf litter, not a fungal growth, actually benefits plants.
About this Author
Alice Moon is a freelance writer with more than 10 years of experience. She was chosen as a Smithsonian Institute intern, working for the National Zoo in Washington, D.C., and has traveled throughout Asia. Moon holds a Bachelor of Science in political science from Ball State University.