|I have been having a problem with my Shasta daisy and black-eyed Susan plants. One day they are growing and blooming really well, and then the next day one will turn black and die, while the other plants of the same type will stay healthy. This happens in the spring or fall. What is happening?
|Both of these plants are subject to stem rot caused by a fungal organism. Unfortunately, there is not much you can do to treat it except pull and destroy the affected plants. It is soil-borne and will be particularly bad in wet, cool spring and fall weather. I suggest pulling the affected plants and leaving the spot bare for the summer or putting in something that is not in the aster/daisy family. If you have an area with soil that drains better than the current site, transplant your flowers to that area, or create a raised bed to help keep their roots well aerated. Also, make sure you have plenty of circulation between plants so reduce further incidence of the disease. Hope this takes care of the problem.