If any of you have Ligustrum (aka Privet), plants in your landscape, there’s a good chance they may have Cercospora Leaf Spot on their foliage.
Symptoms to look for include irregular brown spots with yellow margins on the upper leaf surface and brown spots with purple margins on the underside. These symptoms are particularly noticeable on older plantings which also display thinning canopies, and although more noticeable in late summer-fall, can occur anytime day temperatures are 7o-80 degrees and down to 60 at night. This fungal disease at best is difficult to control, and although many homeowners have this problem, they consider it of minor importance and ignore any treatment. Only after several years of decline do they become concerned, and by that time there’s not a lot that can be done, so they remove the infected plants.
By now you may be asking is there anything I can do, and my answer is yes. Avoid over watering, especially at night, clean up any infected leaves, thin out the canopy to provide good air movement, and provide good culture. Applying repeated applications of Daconil, Dithane, or Cleary 3336 also seem to help. Remember, when using any pesticide, always read and follow label directions.
For more information about this disease click here.
asktheplantmaster 
I have lots of milkweed this year. It came out extra thick. I am having a problem with a orange and black bug that I think is called the milkweed bug. How do I get rid of them before they destroy my milkweed. I keep finding black spots on the leaves and a lot of yellow leaves.
I do have one Chrysalis, that should before a Monarch in a few days, but haven’t found any other eggs or cats yet, but are still looking of course.
Hope you can help me.
Judith,
Sorry for my delay in responding to your recent comment from my website. I really appreciate your visiting it and welcome any and all comments.
You asked about controlling the milkweed bug. I suggest you apply Safer Insecticidal Soap which can be purchased at most box stores or garden centers. However, I think by now they have probably left your plants and moved on. If not the soap should work. Because you want to protect the monarchs, be very careful in the pesticides that you use, such as neonecatides, as they can kill the butterfly by ingesting the pollen or nectar.
Again thanks for your question, do not hesitate to contact me with any other questions or concerns.
Howard Jeffries