Hi, I have some viburnum shrubs which the leaves tend to have a white/yellow effect on them around late October. It only happens this time of the year and I am wondering why this is.
This appears to be a fungal issue, or pH issue, or even both! To correct this, I would recommend applying wettable sulfur to the area, and applying dolomitic lime to adjust pH. This can correct your issue, and even if there is no infection, the sulfur will help keep the soil clean, and free of infection in the future. This article will give you more information on the proper care of these:https://www.gardeningknowhow.com/ornamental/shrubs/viburnum/viburnum-shrub.htm