Root fungus problem
I have been trying to plant more native plants, and this year had a great stand of Mist Flower. However, it suffered a major die-back in several of my beds. We have quite a bit of shade, and had a wet spring this year in Houston, so perhaps that contributed to the problem. Some of my Asclepias and goldenrod suffered a similar fate. I am attaching two photos - I am just assuming that it is a fungal problem. Do you have any suggestions about what I can do? Thank you very much!
From the photos, it appears to be a fungal problem commonly known as Southern blight, caused by the fungus Sclerotium spp. This fungus can infect many different types of plants , including numerous ornamentals. IF this is a critical management situation, it is suggested that a confirmatory diagnosis be obtained to help with future planting plans.
For some more information about this disease problem, see the following links: