Every year there seems to be another emerging threat to our plants that is fungal in nature. Nantucket’s intrepid gardeners are all used to fighting with black spot on roses and powdery mildew on border phlox, but there are many other spores and spots floating around out there that effect other species. One the up-and-comers is an infection that effects privet: Alternaria Leaf Spot.
This fungus causes ugly necrotic spots on the leaves, followed by yellowing and leaf drop. Severely effected plants can have substantial defoliation by the end of the growing season. Like many fungal diseases, symptoms usually first appear inside the plant where air circulation is low. This often makes early detection a problem, so treatment is delayed.
As far as we know, this fungus is more of a problem in production nurseries where thousands of privet plants are grown close together, providing a constant supply of inoculum for reinfection. Although we have seen spots similar to these on privet on Nantucket in the past, our customers didn’t report any widespread issues with this fungus last summer.
For more information on Alternaria Leaf Spot, check out this link to Cornell extension: http://ccesuffolk.org/assets/galleries/Agriculture/Commercial-Nursery-and-Landscape-Management/Alternaria-leaf-spot-on-privet-fact-sheet-revised-4-11.pdf
We source our privet from reputable growers and haven’t found alternaria leaf spot to have been a problem with our suppliers in the past. However, we do inspect each shipment as it arrives and will continue to make selling the highest quality plants our goal.