Aucubas with black ends of their leaves - Ask Extension
Please let me know if this is something we need to take care of, or it will go on its own. The uploaded Aucubas have dark black spots on their leaves,...
Knowledgebase
Aucubas with black ends of their leaves #879565
Asked July 31, 2024, 11:14 AM EDT
Please let me know if this is something we need to take care of, or it will go on its own. The uploaded Aucubas have dark black spots on their leaves, thanks,
Montgomery County Maryland
Expert Response
Darkened leaves on Aucuba can be difficult to diagnose, as there can be several potential (or overlapping) causes. There might be root issues (if the plant's roots got too wet earlier this spring, when the weather was quite rainy), and if some dieback occurred, then the remaining roots might be struggling to keep the foliage hydrated during this drought. The dying leaf tips could also be due to a fungal leaf spot or stem blight.
In either case, no intervention can cure existing symptoms, so you can selectively trim off damaged leaves if you prefer. Fungicide is not needed for the rest of the season, and would be difficult to apply anyway while we experience stretches of hot weather, as most pesticides should not be applied while temperatures are above 85 degrees (or else they risk injuring the plant tissues themselves). For now, just continue to monitor the plant for watering needs, and if any of the discolored leaves fall off, collect and dispose of them so they don't harbor spores for re-infection in the spring.
Miri
In either case, no intervention can cure existing symptoms, so you can selectively trim off damaged leaves if you prefer. Fungicide is not needed for the rest of the season, and would be difficult to apply anyway while we experience stretches of hot weather, as most pesticides should not be applied while temperatures are above 85 degrees (or else they risk injuring the plant tissues themselves). For now, just continue to monitor the plant for watering needs, and if any of the discolored leaves fall off, collect and dispose of them so they don't harbor spores for re-infection in the spring.
Miri
Thank you Miriam!:)
Susy
You're welcome!
