Thanks for reaching out. Sorry to say, for some reason, the photo won’t open at all. Could you kindly try to send a photo again?

Thanks,

Kate McLynn, Extension Volunteer Team

Yes, this one came through and is quite clear, thank you.

Unfortunately, this looks like Southern Blight, noting the round “mustard seed” sclerotia.

As you have observed nearly every plant we grow in our ornamental and in our food gardens is susceptible. The fungus Agroathelia rolfsii (=Sclerotium rolfsii) is long-lived,  lurks in the soil until the right conditions such as heat and humidity occur for it to activate.

There isn’t a cure, but you can prevent further spread by removing and discarding all affected plant parts and the top layer of soil, a couple inches if you can manage. https://content.ces.ncsu.edu/southern-blight-of-herbaceous-ornamentals
A. Rolfsii thrives in moist acidic conditions. So apply agricultural lime.

Optional but advisable, this is a good time of year for solarizing, being sure to moisten the soil & trench in the plastic edges for a tight seal, which will kill the fungus near the surface. https://content.ces.ncsu.edu/weed-management-on-organic-farms#Solarization

A. rolfsii requires light, so after solarizing (if doing), otherwise jump to step two, which is to bury the area under soil from elsewhere in the garden.  If needed, you can or reduce the amount of soil needed by first applying a thick layer of wood chips (avoid using material from plants that are A. rolfsii susceptible. Then cap with a few inches of soil from elsewhere in the garden.

Then plant the area with non-susceptible plants for the about next 5 years or so. Suggest Little Bluestem, an attractive native grass of modest height that can tolerant higher pH soil than some plants, but there are many beautiful grasses, https://extension.umd.edu/resource/ornamental-and-native-grasses-landscape/.

Clean all garden tools, pots, etc. Involved thoroughly to avoid spread.

Mulch with an organic mulch (non susceptible), avoid disturbing the soil and allow time and soil biome to help extinguish the A. rolfsii.

So glad you spotted it before it spread further!

Please feel to reach out with further questions and keep us posted!

Kate McLynn Extension team volunteer

Much appreciated!