White Mold on Stems of Plants

Asked July 28, 2016, 10:24 AM EDT

Hello, I have observed what looks to be white mold on several different plants, including Ammi, Hydrangea, Shiso, and African Blue Basil. The plants are planted in different parts of my yard. Mostly it has just been on the stems, but today I observed it on the underside of Annabelle Hydrangea leaves, as you can see in the attached photos. What is causing this? Do I need to eliminate it? If so, is there an organic way to do so? Thank you. Best, Lisa Derx

Howard County Maryland

3 Responses

This is not mold. Rather, it is the white waxy substance produced by planthoppers. It is not damaging and does not require any treatment. Here is info about it from our website: http://extension.umd.edu/hgic/planthoppers-flowers


Relieved to hear this isn't a problem! Thank you so much.