My virginia sweetspire bushes and spirea bushes have red spots or marks on the leaves. Some spots are round while others are different shapes. We have had an enormous amount of rain this summer. My plants are located in the front of my house that does not get the sun until afternoon. My beds are mulched, however when I noticed the red marks I pulled the mulch from the bottom of the bushes to help the ground dry out. I can't find much information on red marks on leaves. Will this hurt the plants and what can I do to help them. I really don't want to get rid of them. Thank you.
Certified GKH Gardening Expert
It appears to be fungal leaf spot disease. The shady morning growing conditions and wet environment are contributing to the susceptibility. You can't change the sun exposure, and you won't be able to cure the existing leaf spots, but you can prevent further infections this season with a systemic fungicide spray. I like propiconazole (start again in spring for preventive action):