Garden Pests and Diseases: Anybody know what this is?, 0 by plantladylin

plantladylin wrote:
I have this grayish looking growth on the foliage of one of my Hoya plants and don't have a clue what it is or how to treat it. I'm hoping someone might recognize it and have some advice. It's only affecting the reverse side of the leaves and only on three leaves. I've quarantined the plant because I sure don't want it to spread to my other plants. I hate the thought of having to destroy the plant so I'm hoping someone will be able to tell me what this is, some kind of scale, canker, fungal infection ...

Thanks in advance for any advice and help.

Lin