Black spots on winterberry leaves - Ask Extension
This fall my winterberry leaves were covered with black spots about the size of a lentil. They were slightly raised and appeared on each side of the ...
Knowledgebase
Black spots on winterberry leaves #922576
Asked December 01, 2025, 4:47 PM EST
This fall my winterberry leaves were covered with black spots about the size of a lentil. They were slightly raised and appeared on each side of the leaves, as though the spots had grown through the leaves. Anything to worry about?
Baltimore City County Maryland
Expert Response
This looks like a fungal disease called Tar Spot, and while we see the condition most often in maples, that group of fungi can infect winterberry and other species as well. Fortunately, it's only a cosmetic problem, so the health of the plant isn't significantly affected. No treatment is needed (or effective once symptoms manifest), but if you prefer, you can rake up the fallen leaves and dispose of them (or hot-compost them) to reduce the amount of overwintering spores. That's not guaranteed to prevent infection in future years, as spores for many plant diseases can be windblown (and disease spread and severity can be highly dependent on weather any given year), but it may help to avoid prominent outbreaks.
Miri
Miri
