We had a powdery mildew problem a few weeks ago. We alternated spraying with potassium bicarbonate, and also some bacteria that is a biocide. That and careful humidity control took care of it completely in less than a week.
ucb883 Reviewed by ucb883 on . Powdery Mildew Spots on Fan Leaves The spots rub off easy but do come back. Environment is good! I think it started during the time when clones were misted. What is the best way to remedy. Thanks. Rating: 5